Usmle review

Danil hammoudi.md

Sinoe medical association

 

 

Plasma cells are the end-effector cells of the B-lymphocyte lineage that produce and secrete antigen specific antibodies.

 

 

 

B-lymphocyte

Antibody

 

 

 

Plasma cells originate from antigen specific B cells after a number of activation, proliferation, and differentiation steps.

 

 

 

Malignant Plasma Cells

 

However, when plasma cells become malignant due to a variety of causes multiple myeloma is the result.

To the left is an immunohistochemistry stain of a bone marrow biopsy.

 The University of Arkansas for Medical Sciences was one of the first hospitals to use this particular method of staining for the CD-38 marker found on all plasma cells (in red).

 

·        The normal plasma cell is a long-lived, mononuclear cell that does not divide.

·         Plasma cells develop from an earlier precursor, the slowly proliferating plasmoblasts.

·        These cells migrate to the bone marrow from lymph nodes after stimulation by antigen and helper T cells.

·        Plasma cells produce most of the IgG and IgA in the serum, at a production rate of 1 ng per cell per day.

·         After several weeks to months, apotosis (programmed cell death) of normal plasma cells occurs in the bone marrow.

·        In contrast to normal plasma cells, myeloma cells have the appearance of immature plasmoblasts.

·         Myeloma cells do not differentiate completely and are slow to proliferate.

·         Their failure to differentiate is believed to be the result of chromosomal translocations, deregulation, or mutation of particular cancer genes.

·        Although the exact etiology of MM is unknown, current evidence supports a "two-hit" hypothesis

·         The two-hit hypothesis suggests that,

1.      first, a cancer-stimulating event causes a subclinical monogammopathy;

2.       then a second event leads to the development of MM.

·        Exposure to these combined oncogenic events leads to the expression of the cancerous potential within the plasma cell.

·        As a result, myeloma cells show continuous growth and prolonged survival.

·        The survival of these myeloma cells is further enhanced by the presence of interleukin-6.

·         Myeloma cells contain receptors for interleukin-6, and when interleukin-6 binds to this receptor, it promotes tumor growth and prolongs cellular survival.

·         The combination of growth and prolonged survival lead to the clinical features of multiple myeloma

 

 

 

Plasma cell proliferation may occur in several anatomical sites as witnessed by the existence of multiple plasma cell-rich areas:

  • lamina propria of the intestine
  • medullary cords of lymph nodes
  • white pulp and periarterioral sheaths of the spleen
  • submucosa of the upper airways
  • bone marrow

 

 

 

 

 

 

 

 

 

 

Malignant Plasma Cells

When plasma cells become malignant, the disease multiple myeloma is diagnosed, a neoplasm characterized by the accumulation of monoclonal plasma cells which show 3 features:

  • IgG or IgA is the primary isotype of the secreted monoclonal immunoglobulins.
  • Malignant plasma cells localize uniquely within the bone marrow. These cells are referred to as multiple myeloma cells.
  • These cells also produce a number of cytokines, some identified as osteoclast activating factors, which in abundance cause the osteolytic lesions characteristic of multiple myeloma due to their abnormal resorption of bone, resulting in some cases in osteoporosis.

 

 

The normal cell counts are listed here demonstrating normal blood cell composition.

However, with multiple myeloma, all these blood cell counts become significantly reduced, leading to anemia, neutropenia, and thrombocytopenia.

 

 

multiple myeloma

  1. Multiple myeloma is a malignant tumor of plasma cells that causes widespread osteolytic bone damage.
  2.  Multiple myeloma is the most common primary tumor of bone and is found in the spine, skull, ribs, sternum and pelvis but may affect any bone with hematopoietic red marrow
  3. Multiple myeloma is a debilitating malignancy that is part of a spectrum of diseases ranging from monoclonal gammopathy of unknown significance (MGUS) to plasma cell leukemia
  4. Multiple myeloma can cause a wide variety of problems.
  5. The proliferation of plasma cells may interfere with the normal production of blood cells, resulting in leukopenia, anemia, and thrombocytopenia.
  6. The cells may cause lytic lesions in the skeleton or in soft tissue masses[osteoclast activating factors] .
  7. Feared complications of this malignancy are

1.      bone pain,

2.       hypercalcemia,

3.      and spinal cord compression.

  1. The aberrant antibodies that are produced lead to impaired humoral immunity, and patients have a high incidence of infection, especially with encapsulated organisms.
  2. The overproduction of these antibodies may lead to

1.      hyperviscosity,

2.      amyloidosis,

3.      and renal failure

 


·        most common primary malignant neoplasm of bone

·        50-70y; M:F 2:1

·        symptoms: vague bone pain of progressive severity, fever, anemic sxs

·        complications: pathologic fractures

·        solitary plasmacytoma: solitary osseous focus of MM (uncommon)

 

x-ray findings:

·        loss of bone density - from diffuse marrow involvement

·        "punched out" lesions - esp. skull, long bones

·        diffuse bone destruction - esp. pelvis, sacrum

·        invasion of soft tissues - often paraspinal, extrapleural mass

·        osteosclerosis - very rare

·        metastatic calcifications - particularly kidneys, occ. lungs

NB: does not involve pedicles of spine

·        The malignant cell of myeloma is believed to originate at a stage of B lymphocyte ontogeny in a cell more primitive than the end stage mature plasma cells which make up the bulk of the tumour.

·         Unique immunoglobulin gene rearrangements can be demonstrated in the malignant plasma cells of most individuals and these rearrangements are stable throughout the course of the disease.

·         Immunoglobulin gene rearrangement studies demonstrate that the process of somatic hypermutation has already occurred in the malignant clone, thus indicating that the cell of origin is at the stage of pre-plasma cell or memory B cell in lymphocyte differentiation.

·         Such mutations in the immunoglobulin gene, by uniquely identifying the gene sequences of the idiotype, have allowed the development of sensitive assays for minimal residual disease based on the highly specific sequences of the complementary determining regions (CDRs) of the immunoglobulin gene as well as the development of in situ hybridisation staining of individual malignant cells to determine more accurately blood contamination and tissue distribution.

·        Although previously thought to have been infrequent, recent studies have demonstrated the existence of chromosomal abnormalities in almost all patients with myeloma

·        Abnormalities frequently involve the immunoglobulin heavy chain gene locus on the long arm of chromosome 14, often with translocations to a number of different non-immunoglobulin genes containing partner chromosomes.

·         The site of translocation on chromosome 14 is different, however, from the sites of translocations seen in other B cell malignancies.

·         In myeloma, the translocation involves the immunoglobulin switch regions which regulate heavy chain class switching to either the alpha, gamma, or epsilon chains.

·        The non-immunoglobulin partners include chromosomes such as 11q, 4q, 6p and 16q, and newly identified oncogenes have been shown to be present at some of these breakpoints.

·         Such genes include cyclin D, fibroblastic growth factor, and interferon regulatory factor IV.

·         Interestingly, these cytogenetic changes are also present in patients with monoclonal gammopathy of uncertain significance (MGUS), suggesting that they are fundamental to the disease process but that additional events are required to develop fully the malignant phenotype.

·         Another frequent and significant chromosome abnormality is the loss of chromosome 13, which has proven to be a significantly adverse prognostic indicator in patients with myeloma.

·        Various other genetic abnormalities have been observed in patients with myeloma.

·        These include ras mutations, retinoblastoma gene loss, p53 mutations and cyclin D inhibitor abnormalities.

·        Such abnormalities are more often observed in patients with advanced disease and thus may be a reflection of increasing genetic instability as the malignancy progresses

 

 

·        The Role of Human Herpes Virus 8 (HHV8) Infected Stroma in Myeloma

·        Studies on the bone marrow stromal cells of myeloma patients have identified a key role for these cells which secrete cytokines crucial to the growth of the malignant clone, as well as an involvement in a variety of mechanisms which lead to the prevention of apoptosis in malignant plasma cells.

·        For instance, Interleukin 6 (IL-6) produced by bone marrow stromal cells has been demonstrated both to enhance growth and prevent apoptosis of malignant plasma cells.

·        HHV8 is a newly identified herpes virus which was first described in cases of HIV associated Kaposi's sarcoma.

·        It has also been identified in two other B cell disorders, primary effusion lymphoma and multi-centric Castleman's disease.

·         In these cases the virus is localised to the malignant cells.

·         By contrast, some groups have recently documented HHV8 sequences in the genome of the stroma cells of patients with myeloma but not in the stromal cells of other lymphoid malignancies.

·        HHV8 has been reported in both bone marrow biopsies and peripheral blood, and although different sequences have been determined among different patients, the same sequence has always been found in one particular patient at different sites.

·        These and other workers on HHV8 have found, for instance, a viral homologue for the IL-6 gene, thus raising the possibility that virally infected stromal cells could potentiate the malignancy

·        By contrast, European and other US-based studies have not always identified the virus, raising the question of whether this agent is truly aetiological or, perhaps, a reflection of HHV incidence in various population groups.

·        Thus any possible role for this virus in the development of myeloma at this stage remains unclear and any potential studies to assess the possible utility of antiviral therapies have not yet been initiated.

 

 

·        The presenting symptom of multiple myeloma is usually pain. The patient may have a normocytic, normochromic anemia secondary to marrow failure and an increased ESR.

·        Hypercalcemia may cause confusion, weakness and lethargy. Other symptoms may include cachexia, spinal cord compression and renal insufficiency.

·        Bacterial infections are common because of a lack of normal immunoglobulin production.

·         Monoclonal immunoglobulin is found on serum electrophoresis. Light chain subunits of immunoglobulin are called BenceJones proteins and are present in urine.

·        The radiological appearance of multiple myeloma is characterized by irregular lytic defects of different sizes. These lytic areas are often described as "punched out" and have no periosteal reaction.

·         Erosion begins intramedullarly and progresses through the cortex.

·         MRI is useful for delineating spinal lesions.

·         Bone scan can fail to have increased uptake in 25% of patients suggesting a plain film skeletal survey should always be done.l

·        On gross examination, the marrow space has been replaced by a diffuse gelatinous red brown tissue. Tumor nodules of approximately 1 cm in size may be present.

·        Microscopically, multiple myeloma is composed of sheets of plasma cells. The degree of cytologic atypia of these cells has no prognostic value.

·         The osteolytic lesions are caused by increased osteoclastic resorption that is stimulated by cytokines released by-the plasma cells.

·        Treatment of multiple myeloma consists of palliative chemotherapy or bone marrow transplant.

·        Only patients with complete remission of their disease experience any bony healing.

·        Bisphosphonates are used to inhibit resorption of bone and subsequent hypercalcemia.

·         Untreated, a patient with bony lesions will only survive an average of 6-12 months.

·         The cause of death is usually infection or a hemorrhage.

 


·        A hallmark of the diagnosis of MM is the demonstration of monoclonal kappa or lambda light chain on serum or urine electrophoresis.

·        An elevated IgG component is the most frequent abnormality found (53%), followed by elevated IgA (25%) and elevated IgD (1%).

·        About 20% of those with MM also have an M-spike on electrophoresis due to the monoclonal light chains (Bence Jones protein).

·          Urine protein electrophoresis is the most efficient test to detect these monoclonal light chains (Bence Jones proteinuria).

·        Less than 1% of MM patients present with no monoclonal proteins detected, thus resulting in what is termed the "nonsecretory" form of the disease.

·        In these cases, immunofluorescent staining of plasma cells is necessary to identify the monoclonal light chains.

·        Definitive diagnosis is made by bone marrow aspiration/biopsy confirming plasma cell proliferation.

·        A plasma cell content of 15 to 20% is necessary for definitive diagnosis (normal is less than 5%).

·        In addition to the nonsecretory form of MM, some patients have a monoclonal gammopathy of undetermined significance.

·        These patients have elevated serum monoclonal IgG or IgA without evidence of MM.

·        Monoclonal gammopathy is relatively common, occurring in about 0.15% of the general population.

·        Long-term follow-up of these patients is critical given that overt MM can develop in 16% of these patients.

·        Continued surveillance using radiography and protein electrophoresis is necessary.

Mortality/Morbidity:

  • Multiple myeloma affects the kidneys in several ways. The most common means of renal injury are
    1. direct tubular injury,
    2.  amyloidosis,
    3. or involvement by plasmacytoma.
  • Physicians manage the acute picture with plasmapheresis to rapidly lower circulating abnormal proteins.
  • Conventional therapy may take weeks to months to show benefit.
  • Renal impairment resulting from myeloma carries a very poor prognosis.

  • Spinal cord compression is one of the most severe adverse effects of myeloma.
  •  Reports indicate that as many as 20% of patients develop spinal cord compression at some point during the course of their disease.
  • Symptoms typically are back pain, weakness in the legs or paralysis, numbness, or dysesthesias in the lower extremities.
  • However, patients may present with upper extremity symptoms.
  • The mechanism of these symptoms may be the development of an epidural mass with compression, a compression fracture of a vertebral body destroyed by myeloma, or, rarely, an extradural mass.
  • The dysfunction may be reversible, depending on the duration of cord compression;
  •  however, only rarely is the dysfunction fully reversed.

 


  • A frequent complication of multiple myeloma is pathologic fractures.
  •  Bony involvement typically is lytic.
  • Physicians should orthopedically stabilize (ie, typically pin) and irradiate these lesions.
  • Careful attention to a patient's bony symptoms, intermittent radiographic surveys, and the use of bisphosphonates may be useful to prevent fractures.
  • Patients with myeloma commonly develop hypercalcemia.
  •  The mechanisms include bony involvement and, possibly, humoral mechanisms.
  • Treatment for myeloma-induced hypercalcemia is the same as for other malignancy-associated hypercalcemia;
  • however, the dismal outcome observed with hypercalcemia in solid tumors is not observed in myeloma.

 

 

·       
Risk Factors

Age:

Perhaps the most significant risk factor for multiple myeloma is age, the median age at diagnosis being 72 years.

Multiple myeloma is rare in people under 40, with a progressive increase in incidence with age.

To the right is a logged graph that shows the dramatic increase in incidence from age 40 to >80.

 

In a study detecting MGUS with M-protein serum levels, the incidence increases 20-fold when comparing patients aged 30-49 and patients aged 70-89.

 

 

 

Race:

  • Multiple myeloma is about twice as common for African Americans as white Americans in the United States.
  • The incidence of disease is lowest in Japan, with only a 2.7% detection of monoclonal protein in the serum in persons over age 60 as compared to a 10% detection in the U.S.

 

 

 

Genetics:

  • The incidence of multiple myeloma is lowest among Japanese and Chinese people regardless of which country of residence, suggesting that the disease is determined more by genetic than environmental factors.
  • Neither blacks nor whites showed a change in incidence when comparing different countries of residence.

 

 

A large study was done on white & black males to determine whether there was an association of human leukocyte antigens of class I and Class II with the disease:

  • Black cases had higher frequencies for
      1.  Bw65,
      2. Cw2,
      3.  DRw14.
  • White cases had higher gene frequencies for
      1. A3
      2. Cw2.
  • These findings suggest that the Cw2 allele confers susceptibility to the development of multiple myeloma, but doesn't explain the higher risk among blacks.

A study was done using 43 families to determine the genetic association among those with either MGUS or multiple myeloma:

  • Of the 43 families, MM or MGUS was detected in 7 first-degree relatives (parent and child), 23 second-degree relatives (siblings), one third degree relative (aunt, niece), and 3 fourth degree relatives (first cousins).
  • However, no clear Mendelian pattern of inheritance has been established for MM or MGUS.

 

 

 

 

Smoking:

Studies have shown that the risk of developing myeloma is 3-fold greater in subjects who have ever smoked than in those who had never smoked.

 

 

 

 

Occupation:

Studies have also shown a positive association between the following specific occupations/industries and myeloma:

  • agriculture (predominantly farming)
  • metals
  • rubber manufacturing
  • occupations where workers are exposed to benzene or asbestos
  • petroleum refining and petroleum production
  • fuel combustion
  • wood, leather, and textile production
  • painting
  • hair dye manufacturing

 

 

 

No Longer Considered Risk Factors:

Radiation Exposure:

Although studies done on Hiroshima/Nagasaki radiation exposure survivors between 1950 and 1976 showed a positive association with multiple myeloma, reanalysis of the data using updated methods (Dosimetry System) shows no such association with the disease nor frequency of a monoclonal gammopathy.

 

 

 

 

 

Socioeconomic Status:

A case-control study at Duke failed to demonstrate any association of myeloma with family income, education, occupation, dwelling size or an index of crowding in the home.

 

 


Symptoms


The symptoms of multiple myeloma most commonly include one or more of the following:

·        bone pain and skeletal fractures, including compression fractures of the spine, which can cause severe pain and neurologic symptoms

·        infections, especially bacterial infections of the respiratory and urinary tracts

·        generalized symptoms including fatigue, weight loss, and general malaise, which can relate to anemia

·        hypercalcemia, which can cause nausea, vomiting, altered mental states, depression, headache, and in severe cases, coma

·        loss of kidney function, which can cause fatigue, a buildup of fluid in the lower limbs, and excessive thirst

·        hyperviscosity (a thickening of the blood caused by excessive protein) can cause bruising, rash, nosebleeds, vision loss, headache, dizziness, and peripheral neuropathy (numbness, tingling, burning pain in the extremities)

 

 

 

In about one third of patients, multiple myeloma is detected before symptoms appear, through routine blood tests that pick up elevated levels of immunoglobulin proteins

The symptoms of MM vary from person to person, and will depend on the extent and stage of the disease. The symptoms are caused by the malignant plasma cells and the myeloma paraproteins they produce.

Symptoms involve three major body systems; the skeletal system, the renal system and the bone marrow.

·        The Skeletal System

The most common symptom associated with MM is bone pain.

Bone pain is experienced by approximately 70% of myeloma sufferers.

Pain is frequently felt in the

·         lower back,

·          ribs

·          spine,

·         and is caused by myeloma cells eroding the bones causing them to fracture easily.

On x-ray imaging, the areas of myeloma activity can be seen as "punched out" lesions on the bone surface

 

Bone erosion may lead to hyper-calcemia (high blood calcium levels). People suffering from hyper-calcemia may experience symptoms of confusion, nausea, tiredness, constipation, thirst, increased urine output, and dehydration.

 

·        The Renal System

Kidney problems occur in approximately 50% of patients with MM at some stage of their illness.

Kidney function may be affected for a number of reasons.

 Firstly, the myeloma proteins circulating in the blood can be deposited in the kidneys and cause obstruction and inflammation.

 (Those abnormal proteins excreted in the urine is called Bence-Jones protein.)

 

Secondly, calcium from the eroded bones may be deposited in the kidneys causing obstruction and inflammation.

Kidney failure can result if these causes of kidney function are left untreated, especially if dehydration should develop.

 

Other aggravating factors may include urinary tract infection and high blood urate level that MM patients are also prone to develop.

 

 

·        The Bone Marrow

Plasma cells are predominantly found within the bone marrow, which is the location of blood cell production. When the plasma cell becomes malignant it gradually takes over of the bone marrow, preventing it from producing normal blood cells. As such, myeloma sufferers may experience

·        anemia,

·         thrombocytopenia

·        leukopenia.

 

 

Another complication of multiple myeloma is hyper-viscosity.

This condition occurs in approximately 5% of individuals with myeloma.

It refers to the presence of high concentrations of myeloma paraprotein in the blood.

 These paraproteins increase the ‘viscosity’ or thickness of the blood, potentially impairing blood circulation.

The viscous blood flow may provoke a heart attack or stroke.

 Similarly impeded circulation to small blood vessels in the eyes may cause visual disturbances or blindness.

 Restricted blood circulation to the vessels of organs or limbs may lead to pain and tissue necrosis.

 

Presenting symptoms include

1.      bone pain,

2.      pathologic fractures,

3.      weakness, anemia,

4.      infection (often resulting from pneumococcal infection),

5.      hypercalcemia,

6.      spinal cord compression,

7.      or renal failure.

Physicians increasingly are identifying asymptomatic patients through routine blood screening.

 Typically, a large gap between the total protein and the albumin observed on an automated chemistry panel suggests a problem (ie, protein minus albumin equals globulin).

  • Bone pain
    • This is the most common presenting symptom. Most series report that 70% of patients have bone pain at presentation.
    • The lumbar vertebrae are one of the most common sites of pain.
  • Pathologic fractures and bone lesions
    • Pathologic fractures are very common; 93% of patients have more than one site of bony involvement.
    • A common presentation is a severe bony event.
  • Spinal cord compression
    • The symptoms that concern physicians are back pain, weakness (the most common cause of weakness in patients with myeloma is anemia, which may be quite severe), numbness, or dysesthesias in the extremities.
    • Patients who are ambulatory at the start of therapy have the best neurologic outcome.
    • This complication occurs in approximately 10-20% of patients at some time during the course of disease.
  • Bleeding
    • Occasionally, a patient may come to medical attention for bleeding resulting from thrombocytopenia.
    • In some patients, monoclonal protein may absorb clotting factors and lead to bleeding, but this development is rare.
  • Hypercalcemia
    • Patients may have hypercalcemia if they present with confusion, somnolence, bone pain, constipation, nausea, and thirst.
    • This complication may be present in as many as 30% of patients at presentation.
  • Infection
    • Abnormal humoral immunity and leukopenia may lead to infection.
    • Pneumococcal organisms commonly are involved, but shingles (ie, herpes zoster) and Haemophilus infections also are more common among patients with myeloma.
  • Hyperviscosity
    • Epistaxis may be a presenting symptom of myeloma with a high tumor volume. Occasionally, patients may have such a high volume of monoclonal protein that their blood viscosity increases, resulting in complications such as stroke, myocardial ischemia, or infarction.
    • Patients may report headaches and somnolence, and they may bruise easily and may have hazy vision. Patients typically experience these symptoms when their serum viscosity is greater than 4 times that of normal serum.
  • Neurologic symptoms
    • Carpal tunnel syndrome is a common complication of myeloma.
    • Meningitis (especially resulting from pneumococcal or meningococcal infection) is more common in patients with myeloma.
    • Some peripheral neuropathies have been attributed to myeloma.

Physical:

  • Patients may have pallor resulting from anemia.
  • Patients may have ecchymoses or purpura resulting from thrombocytopenia.
  • Bony tenderness is common, resulting from focal lytic destructive bone lesions or pathologic fracture.
  • Neurologic findings may include a sensory level change (ie, loss of sensation below a dermatome corresponding to a spinal cord compression), weakness, or carpal tunnel syndrome.
  • Extramedullary plasmacytomas
    • These plasmacytomas, which consist of soft tissue masses of plasma cells, are not uncommon.
    • Plasmacytomas have been described in almost every site in the body.
    • Although the aerodigestive tract is the most common location, reports also describe orbital, ear canal, cutaneous, gastric, rectal, prostatic, and retroperitoneal lesions.
  • Amyloidosis
    • Some patients with multiple myeloma develop amyloidosis.
    • The characteristic physical examination findings that suggest amyloidosis include the following:
      • The shoulder pad sign is defined by bilateral swelling of the shoulder joints secondary to amyloid deposition.
          1. Physicians describe the swelling as hard and rubbery.
          2. Amyloidosis may also be associated with carpal tunnel syndrome and subcutaneous nodules.
      • Macroglossia is a common finding in patients with amyloidosis.
      • Skin lesions described as wax-colored papules and nodules may occur in patients with amyloidosis and most commonly are observed on the face, lips, ears, and torso.
      • Postprotoscopic peripalpebral purpura strongly suggests amyloidosis.
      • Patients may develop raccoonlike dark circles around their eyes following any procedure that parallels a prolonged Valsalva maneuver.
      • The capillary fragility associated with amyloidosis may account for this observation.
  • The accepted schema for diagnosis is as follows:
    • I = Plasmacytoma on tissue biopsy
    • II = Bone marrow with greater than 30% plasma cells
    • III = Monoclonal globulin spike on SPEP with an IgG peak of greater than 3.5 g/dL or an IgA peak of greater than 2.0 g/dL or UPEP (in the presence of amyloidosis) greater than 1 g/24 h
    • a = Bone marrow with 10-30% plasma cells
    • b = Monoclonal globulin spike present but less than category III
    • c = Lytic bone lesions
    • d = Residual normal IgM of less than 50 mg/dL, IgA of less than 100 mg/dL, or IgG of less than 600 mg/dL
  • The following combinations of findings are used to make the diagnosis:
    • I plus b
    • I plus c
    • I plus d
    • II plus b
    • II plus c
    • II plus d
    • III plus a
    • III plus c
    • III plus d
    • a plus b plus c or a plus b plus d

Causes:

  • Genetic causes
    • The Mayo clinic found disease in 8 siblings out of 440 patients; these 8 siblings had different heavy chains but the same light chains.
    • Ongoing research is investigating whether the human leukocyte antigen (HLA)-Cw5 or HLA-Cw2 may play a role in the genesis of myeloma. In small studies, researchers have identified both of these antigens in an increasing number of patients with myeloma.
  • Environmental or occupational causes
    • A British case-controlled study of 399 patients with myeloma reported a relative risk of 1.8 for patients exposed to the agriculture, food processing, and chemical industries.
    • A second study (ie, 100 cases, 100 controls) in Baltimore showed an increased risk of 3.7 for patients exposed to petrochemicals, 3.5 for patients exposed to asbestos, and 3.5 for patients exposed to laxatives.
    • Conflicting data exist regarding an association between hair dye and myeloma. The American Cancer Society prospective mortality study suggested that individuals who have used hair dye for a long time (ie, >20 y) have an increased risk of developing myeloma.
  • MGUS: Approximately 19% of patients with MGUS develop multiple myeloma within 2-19 years.
  • Radiation
    • Radiation is linked to myeloma.
    • In 109,000 survivors of the bombing of Nagasaki, 29 died from myeloma from 1950-1976; however, some recent studies do not confirm that these survivors have an increased risk of developing myeloma.

 

 

 

 

 

HOW IS MYELOMA DIAGNOSED ?

 

The initial approach to the patient is to establish the diagnosis by:

1. Detection of an M-protein in the serum or urine.

2. Detection of more than 10% plasma cells on a bone marrow examination.

3. Detection of lytic bone lesions or generalized osteoporosis in skeletal x-rays.

4. Presence of soft tissue plasmacytomas.

 

 

Other important tests which help to evaluate patients include:

·        b2 microglobulin

·        C-reactive protein

·        blood count

·        calcium level

·        kidney function

·        type of abnormal myeloma protein [bence jones protein type]

Bence Jones protein: a portion of the abnormal myeloma protein referred to as the "light chains

monoclonal (M) protein: the protein made by myeloma cells

·        A critical diagnostic criteria, however, is the characteristic abnormal plasma cell pathology. It is no longer adequate to assume that the demonstration of lytic bone lesions plus a paraprotein is sufficient for the diagnosis. Morphological confirmation can usually be easily sought from bone marrow aspiration or from fine needle aspiration of a skeletal lesion or plasmacytoma. The main differential diagnoses are

·         MGUS,

·         smouldering myeloma,

·        systemic amyloidosis,

·         lymphoma

·         metastatic carcinoma.

·        Newer radiological investigations, such as magnetic resonance imaging (MRI) of the spine, have proven to be extremely useful, especially for the accurate demonstration of neurological complications.

·        In the future, whole body MRI may become the radiological investigation of choice for all myeloma patients.

·         An application of particular importance may be the accurate separation of solitary plasmacytoma from disseminated multiple myeloma.

·        Several additional investigations are of importance in predicting the prognosis and guiding treatment decisions in individual patients.

·        These include

1.      the bone marrow plasma cell labelling index (PCLI)

2.      and blood levels of beta-2-microglobulin ("ß2M),

3.      C-reactive protein,

4.       thymidine kinase

5.      lactic acid dehydrogenase.

 

·        Of these, the ß2M and PCLI are the most powerful predictive assays.

·        The differentiation of smouldering myeloma from active (treatment-requiring) myeloma is not always easy.

·         The decision to instigate specific therapy, as opposed to observation, is based on a number of criteria.

·         Of the laboratory investigations, the PCLI is particularly useful.

·        Using dual colour fluorescent techniques, this assay measures the percentage of plasma cells (bearing the light chain of the malignant clone) in S phase of the cell cycle (detected by propidium iodine or bromodeoxyuridine).

·        Recent adaptation to the flow cytometer has dramatically reduced the labour-intensiveness of this test and thus widened its application.

·        A strongly elevated labelling index suggests that the patient has active disease, while a low labelling index is a sine qua non of smouldering myeloma or MGUS.

·        ß2M largely reflects renal function and is in itself an important prognostic indicator for myeloma.

·         In combination with the PCLI, it provides the most accurate prognostic information, not only in patients who are treated with conventional chemotherapy, but also in patients who are submitted to high dose therapy and transplantation protocols.

·        For instance, a patient under 60 years of age, who presents with a low ß2M and a low labelling index, has a median survival of over six years when treated with conventional chemotherapy alone.

·         The application of information from prognostic marker studies is obviously of great relevance when considering the use of high dose therapy protocols and especially allogeneic transplantation.

 

 

Following this a number of tests will be ordered.

  1. Blood tests are routinely ordered to determine blood cell counts. In approximately 80-90% of cases, the paraproteins produced by the malignant plasma cells can be detected and quantitated in the blood.
  2.  Many patients who have the myeloma protein in their blood also have fragments of myeloma protein in their urine.
  3.  To detect and measure the urinary protein fragments, patients are asked to do a 24 hour urine collection.
  4. . Additional blood tests can ascertain the function of vital organs, blood calcium level, clotting factors, blood grouping, and virology screening such as hepatitis and HIV status.

 

 

  1. X-rays of the bones (Skeletal survey) are frequently taken to determine the extent to which they are affected.
  2.  Typically, x-rays are taken of the chest, spine, pelvis, arms, legs and skull.
  3. Occasionally, CT scans and/or MRI scans are also required.

 

 

Chest X-rays are likely to be taken if a chest infection is suspected.

Blood, phlegm, urine and stool cultures may also be collected to identify the site of infection, especially if fever is present. ECG (electrocardiograph) and GBPS (gated blood pool scan) may be required to assess your heart function.

The diagnosis of multiple myeloma requires examination of the bone marrow.

This procedure is called a bone marrow biopsy, and is performed under intravenous sedation and local anaesthesia. Examination of the bone marrow will show an excessive numbers of plasma cells with an associated reduction in the normal cells.

A bone marrow biopsy is an outpatient procedure performed under local anaesthesia and sedation. Using a special disposable needle and syringe, the doctor will withdraw a small amount of marrow blood from the hip bone (or uncommonly the breast bone), along with a tiny core of bone marrow tissue.

The procedure takes around twenty minutes to complete and involves minimal discomfort.

It is only after these tests are performed that an accurate diagnosis can be made.

The most appropriate therapy can then be recommended taking into account the findings of these test results, current symptoms, age and health history.

 

 

 

 

The following diseases can be associated with secretion of a monoclonal protein (M-Component) in the blood:

·        monoclonal gammopathy of undetermined significance (MGUS)

·        multiple myeloma

·        Waldenstrom's macroglobulinemia

·        malignant lymphoma or primary systemic amyloidosis

Stage Information

 

 

Isolated plasmacytoma of bone

  • If a solitary lytic lesion of plasma cells is found on skeletal survey in an otherwise asymptomatic patient and a bone marrow examination from an uninvolved site contains less than 5% plasma cells, the patient has an isolated plasmacytoma of bone.
  • About 25% of patients have a serum and/or urine M-protein;
  • this should disappear following adequate irradiation of the lytic lesion.
  • When clinically indicated, magnetic resonance imaging (MRI) may reveal unsuspected bony lesions which were undetected on standard radiographs.

 

Extramedullary plasmacytoma

  • Patients with isolated plasma cell tumors of soft tissues, most commonly occurring in the tonsils, nasopharynx, or paranasal sinuses, should have skeletal x-rays and bone marrow biopsy.
  • If these tests are negative, the patient has extramedullary plasmacytoma.
  • About 25% of patients have serum and/or urine M-protein; this should disappear following adequate irradiation.

 

Macroglobulinemia

  • Macroglobulinemia is a proliferation of plasmacytoid lymphocytes secreting an IgM M-protein.
  •  Patients often have lymphadenopathy and hepatosplenomegaly, but bony lesions are uncommon.
  • There is no generally accepted staging system.

·         The term macroglobulinemia describes an increase in the serum concentration of a monoclonal IgM.

·          Most patients are asymptomatic and do not require treatment.

·         The most common symptoms and signs, when they develop, are

§          fatigue,

§         manifestations of hyperviscosity (headache, epistaxis, visual disturbances),

§         and neurologic abnormalities.

§          Lymphadenopathy and splenomegaly are found in about one third of patients.

§          The increased intravascular concentration of high molecular weight IgM leads to an expansion of the plasma volume, a dilutional anemia, and in extreme cases, congestive heart failure.

§         Sludging of the blood can be seen in conjunctival and retinal veins with dilatation and segmentation of vessels ("link sausage" appearance), retinal hemorrhages, and papilledema.

§         Similar problems with the circulation of blood in the CNS can cause ataxia, nystagmus, vertigo, confusion, and disturbances of consciousness.

·        The various disorders associated with the appearance of a monoclonal IgM include:

1. Monoclonal Gammopathy of Undetermined Significance (MGUS). Patients are asymptomatic, the M-protein is stable, and there is no lymphadenopathy, splenomegaly, or bony lesions.

2. Waldenstrom's Macroglobulinemia (WM). Patients are symptomatic, have lymphoplasmacytic marrow infiltration and a rising serum IgM concentration, and may have lymphadenopathy or splenomegaly. Rarely, patients with WM have lytic bone lesions. (Refer to the PDQ summary on Adult Non-Hodgkin's Lymphoma Treatment for more information.)

3. Absolute lymphocyte count exceeding 5,000 cells per cubic millimeter. The patient may be classified as having chronic lymphocytic leukemia (CLL) if the lymphocytes are of the small, well-differentiated variety. CLL must be differentiated from the lymphoplasmacytosis that may occur as a peripheral blood manifestation of WM.

4. Lymphoplasmacytic lymphoma. When a lymph node biopsy demonstrates the pathologic characteristic of a lymphoma, this becomes the diagnosis.

5. Chronic cold agglutinin disease. Patients have a high cold agglutinin titer and no morphologic evidence of neoplasia. These patients often have a hemolytic anemia that is aggravated by cold exposure. The IgM has kappa light chains in more than 90% of these patients.

 

Monoclonal gammopathy of undetermined significance

 

  • Patients with MGUS have an M-protein in the serum without findings of multiple myeloma, macroglobulinemia, amyloidosis, or lymphoma and with fewer than 10% plasma cells in the bone marrow.
  • These patients are asymptomatic and should not be treated.
  • They must, however, be followed carefully since about 2% per year will progress to develop one of the symptomatic B-cell neoplasms and may then require therapy.

 

 

 

MGUS

Smoldering Multiple Myeloma

Overt Multiple Myeloma

 

  • Serum M-Protein (Usually <3 g/dl
  • Few than 10% plasma cells, and no aggregates on biopsy
  • No anemia, renal failure, or hypercalcemia
  • Ancillary tests negative
  • Bone lesions absent on radiographic bone survey
  • Bone marrow contains <10% plasma cells without aggregates on biopsy
  • Bone marrow plasma cell L1<1.0%
  • Plasmablasts absent
  • Serum M-protein (usually >3 g/dl)
  • 10% or more marrow plasma cells or aggregates on biopsy
  • No anemia, renal failure, or hypercalemia attributable to myeloma
  • Ancillary tests negative
  • Bone lesions absent on radiographic bone survey
  • Bone marrow contains <10% plasma cells without aggregates on biopsy
  • Bone marrow plasma cell L1<1.0%
  • Plasmablasts absent
  • M-protein present in serum or urine
  • 10% or more marrow plasma cells or aggregates on biopsy
  • Ancillary findings (one or more): must not be attributable to another cause
  • Anemia
  • Lytic lesions (osteoporosis satisfies if there are 30% or more plasma cells in marrow)
  • Bone marrow L1 > 1%
  • Renal insufficiency (not due to adult-acquired Fanconi syndrome or light-chain deposition disease)
  • Hypercalcemia

 

  • Abnormalities in certain oncogenes and tumor suppresor genes develop at specific times:
  • C-myc is an oncogene which normally promotes cell division and its expression allows for polyclonal plasma cell expansion. Its presence is required for the further development of plasma cell tumors.
  • After this normal process of expansion, a loss of RB or p53 combined with K-ras overexpression allows for uncontrolled myeloma cell proliferation by increasing expression of autocrine IL-6.
  • Oncogenes N-ras and K-ras are more often found in myeloma after bone marrow relapse.
  • Changes in p53, a tumor suppressor gene which normally slows down cell division or causes cells to die at the appropriate time, are associated with spread to multiple organs.

 

 

 

 

Fibroblasts and macrophages in bone marrow stroma release interleukin-6 (IL-6)

IL-6 has the following characteristics:

·        helps normal plasma cells grow

·        excess production of IL-6 by dendritic cells is an important factor in developent of plasma cell tumors

·        clinical studies have revealed that excess IL-6 productive may result from infection with Kaposi's sarcoma-associated herpes virus

Macrophage

 

 

 

Chromosomal abnormalities:

Chromosomal studies involving over 1400 patients have been done since 1959, with 1/3 of MM patients having clonal chromosomal abnormalities.

500 cases were reported including 166 with extensively presented karyotypes.

 

Aneuploidy is a common finding with multiple myeloma:

·        hyperdiploidy mostly involves chromosomes 3,5,7,9,11,19, and 21

·        hypodiploidy commonly affects chromosomes 13,8, and x

·        A common specific abnormality among patients is the t(11;14)(q114;q32) translocation involving the bci-1 oncogene.

Deletion of chromosome 13 is not uncommon and carries a poor prognosis.

Lab Studies:

  • Complete blood count to determine if the patient has anemia, thrombocytopenia, or leukopenia
  • Comprehensive metabolic panel to assess a patient’s total protein, albumin and globulin, BUN, creatinine, and uric acid, which is high if the patient has high cell turnover or is dehydrated
  • Serum protein electrophoresis, urine protein electrophoresis, and immunofixation
    • Serum protein electrophoresis (SPEP) is used to determine the type of each protein present and may indicate a characteristic curve (ie, where the spike is observed).
    • Urine protein electrophoresis (UPEP) is used to identify the presence of the Bence-Jones protein in urine.
    • Immunofixation (IFIX) is used to identify the subtype of protein (ie, IgA lambda).
  • A 24-hour urine collection for the Bence-Jones protein (ie, lambda light chains), protein, and creatinine
    • Quantification of proteinuria is useful for diagnosis (>1 g of protein in 24 h is a major criterion) and for monitoring the patient’s response to therapy.
    • Creatinine clearance can be useful for defining the severity of the patient’s renal impairment.
  • Quantitative immunoglobulins (ie, immunoglobulin G [IgG], immunoglobulin A [IgA], immunoglobulin M [IgM])
    • A minor diagnostic criterion for myeloma is the suppression of the nonmyelomatous immunoglobulin.
    • Also, the level of myeloma protein (ie, M protein level), as documented by the immunoglobulin level, can be useful as a marker to assess the patient’s response to therapy.
  • Beta2 microglobulin
    • Beta2 microglobulin is a very strong predictor of outcome; some studies suggest it is more powerful than stage.
    • Beta2 microglobulin is a surrogate marker for the overall body tumor burden.
    • The level of beta2 microglobulin is increased in patients with renal insufficiency without myeloma, which is one reason that it is a useful prognosticator in myeloma. The prognosis of patients with myeloma and impaired renal function is reduced.
  • C-reactive protein
    • C-reactive protein (CRP) is useful for prognostication.
    • The CRP is a surrogate marker of interleukin (IL)-6 activity. IL-6 often is referred to as the plasma cell growth factor.
  • Check serum viscosity in patients with CNS symptoms, nosebleeds, or very high M protein levels.

Imaging Studies:

  • Skeletal series
    • Perform a complete skeletal series at diagnosis, including the skull (a very common site of bone lesions in multiple myeloma), the long bones (looking for impending fractures), and the spine.
    • Diffuse osteopenia may suggest myelomatous involvement before discrete lytic lesions are apparent.
    • The findings on this evaluation may be used to identify impending pathologic fractures, allowing physicians the opportunity to repair debilities and prevent further morbidity.
    • Do not use bone scans to evaluate myeloma. Cytokines secreted by myeloma cells suppress osteoblast activity; therefore, no increased uptake is observed.
  • MRI scan
    • Findings on MRI scans of the vertebrae often are positive when plain radiographs are not.
    • For this reason, evaluate symptomatic patients with an MRI scan to obtain a clear view of the spinal column and to assess the integrity of the spinal cord.

Procedures:

  • Obtain bone marrow aspirate and biopsy samples to count the percentage of plasma cells in the aspirate (reference range <3%) and to look for sheets or clusters of plasma cells in the biopsy specimen.
  • Cytogenetic analysis of the bone marrow may add significant prognostic information. Abnormalities of chromosome 13 (predominantly monosomy 13) predict a poor outcome. In addition, in MGUS, the presence of monosomy 13 may correlate with subsequent development of myeloma.

Histologic Findings: In patients with myeloma, plasma cells proliferate within the bone marrow, typically in sheets. Plasma cells are 2-3 times larger than typical lymphocytes; they have eccentric nuclei that are smooth (round or oval) in contour with clumped chromatin and have a perinuclear halo or pale zone. The cytoplasm is basophilic. Many descriptions of myeloma cells describe characteristic, but not diagnostic, cytoplasmic inclusions, which include Mott cells, Russell bodies, grape cells, and morula cells. Bone marrow examination reveals plasma cell infiltration, often in sheets or clumps. This infiltration is different from the lymphoplasmacytic infiltration observed in patients with Waldenström macroglobulinemia.

Staging: Staging is a cumulative evaluation of all of the diagnostic information garnered and is a useful tool for stratifying the severity of patients' disease. The staging system for myeloma is somewhat complex, but it is well correlated with outcome.

  • Stage I involves all of the following:
    • Hemoglobin greater than 10 g/dL
    • Calcium less than 12 mg/dL
    • Radiograph showing normal bones or solitary plasmacytoma
    • Low M protein values (ie, IgG <5 g/dL, IgA <3 g/dL, urine <4 g/24 h)
  • Stage II involves criteria that fit neither stage I nor stage III.
  • Stage III involves any one of the following:
    • Hemoglobin less than 8.5 g/dL
    • Calcium greater than 12 mg/dL
    • Radiograph showing advanced lytic bone disease
    • High M protein value (ie, IgG >7 g/dL, IgA >5 g/dL, urine >12 g/24 h)
  • Subclassification A involves creatinine of less than 2.0 g/dL.
  • Subclassification B involves creatinine greater than 2.0 g/dL.
  • Stage I has median survival of longer than 60 months, stage II is 41 months, and stage III is 23 months. Stage B disease has a significantly worse outcome (eg, 2-12 mo in 4 separate series).

 

 

Amyloidosis infiltrating the tongue in multiple myeloma. Reproduced with permission from the American Society of Hematology Slide Bank.

·        Plasma cells are a subset of B cells, which are the producers of humoral immunity factors termed antibodies. Antibody molecules are composed of two polypeptide chains: a light chain and a heavy chain.

·        Cleavage results in the production of Fab and Fc fragments; the Fab fragment is termed the Bence-Jones protein and is found in the urine of patients with myeloma.

·        An individual plasma cell can produce antibody molecules of only a single immunoglobulin to combine with a single antigen.

·        As such, a plasma cell is termed monoclonal.

·        Most infections produce a polyclonal response, since multiple antigens are present on a single bacillus or virus and activate multiple plasma cells.

·        Electrophoresis during infections demonstrates an increase in multiple types of proteins as a result of the multiple humoral and cellular products produced to combat the invading organism.

·        However, if malignant transformation occurs in a single plasma cell, its clones produce only a single type of immunoglobulin, and electrophoresis demonstrates a monoclonal peak corresponding to this particular immunoglobulin.

·        Infection, as well as collagen vascular disorders, rheumatoid arthritis, and ulcerative colitis, also can produce diffuse hypergammaglobulinemia.

·        Waldenström macroglobulinemia, leukemia, lymphoma, and myeloma produce monoclonal peaks.

·        If a monoclonal protein elevation is discovered in a patient and additional tests often do not reveal an underlying etiology, the condition is termed monoclonal gammopathy of undetermined significance.

·        Most of these patients do not progress to multiple myeloma but must be followed up regularly to evaluate for an increase in monoclonal protein levels or the development of lytic bone lesions.

·        The cause of multiple myeloma is unknown.

·        Current theories involve chronic antigenic stimulation of a plasma cell, which results in transformation and the development of myeloma.

·        However, once a plasma cell is transformed, it is known to produce innumerable clones, which spread hematogenously to other myelogenous areas.

·        Once there, these neoplastic cells form sheets that replace the normal bone marrow.

·         In addition, the myeloma cells produce osteoclast-stimulating factor, a cytokine that results in bone destruction.

·         The plasma cell activating factor interleukin 6 is found within bone marrow, resulting in plasma cell proliferation.

·        The osteoblastic response in myeloma tends to be suppressed, resulting in the severe demineralization and bone destruction characteristic of the disease.

·        Secondary hypercalcemia is present

 

Durie and Salmon proposed the initial clinical staging system for multiple myeloma in 1975. Measured myeloma cell mass was correlated with 5 clinical features as follows:

  • Hemoglobin level
  • Serum calcium
  • Number of bone lesions on a radiographic skeletal survey
  • Immunoglobulin level
  • Serum creatinine

Using these 5 features, a 3-stage system was proposed that divided patients into low, intermediate, and high myeloma cell burden.

  • Stage I consists of all the following:
    • Hemoglobin >10 g/dL
    • Serum calcium <12 mg/dL
    • Plasmacytoma to no lytic lesions on a skeletal survey
    • Low immunoglobulin production (immunoglobulin G [IgG] <5 g/dL or immunoglobulin A [IgA] <3 g/dL)
  • Stage II patients are defined as fitting into neither stage I nor stage III.
  • Stage III patients demonstrate one or more of the following:
    • Hemoglobin <8.5 g/dL
    • Serum calcium >12 mg/dL
    • More than one lytic bone lesion on a bone survey
    • High immunoglobulin production (IgG >7 g/dL or IgA >5 g/dL)

 

Amyloid deposition due to the light chains is a frequent complication of multiple myeloma.
The lytic lesion is believed to be due to activation of osteoclasts by cytokines liberated by the plasma cells. These cytokines include IL-1 and TGF-beta.
IL6 may be produced primarily by stromal cells, activated by the plasma cells.
IL6 levels are used to measure progress of the tumor.,

In constructing this staging system, researchers found that stage I patients had a median survival of 191 months, stage II patients survived from 11-54 months, and stage III patients survived from 5-34 months.

In the United States, approximately 10,000 persons per year die from the disease. Without treatment, most patients die in less than 1 year; with treatment, life expectancy may be extended 2-3 years.

Race: No racial predilection exists.

This is a view of the skull from above, after the scalp has been removed.
Note the "punched out" circular, hemorrhagic lesions (some indicated by arrows).
These are the tumor deposits in the bones of the skull.

rib

A higher power view of a deposit of malignant melanoma in bone marrow.
Some of the typical, mature adipocytes of bone marrow are seen in this field.
Most of the other cells in this image however, resemble each other.
A typical cell can be seen at the tip of the black pointer.
It is a large cell, with a nucleus that is placed at one end of the cell.
The cytoplasm is abundant and stains blue (ie. basophilic).
A paler relatively understained area is seen near the nucleus.
These features typify a plasma cell.
Careful examination of this field reveals that most of the cells in this field resemble that cell.
Malignant myeloma is a tumor of plasma cells that arises usually in the bone marrow.

Bone marrow aspiration and biopsy reveals increased numbers of plasma cells (classically >30%, but may be only 10-30%), often forming clusters or sheets of cells replacing normal marrow elements. This results in anemia, leukopenia, and thrombocytopenia.

The growth factor IL-6 is produced in excess in MM and correlates with the proliferation of myeloma cells.

 

The plasma cells seen in the marrow can be mature - with classic PC features or immature - with prominent nucleoli.

Binucleate and multinucleate PCs can be seen.

Masses of immunoglobulin may form intracytoplasmic globules or Russell bodies.

 

Myeloma cells may also contain crystalline inclusions of immunoglobulin (below left).

Cells containing multiple immunoglobulin globules are known as Mott cells (below right).

The excessive production of an abnormal immunoglobulin is the second major characteristic of myeloma.

The abnormal Ig is most often IgG (50%) and sometimes IgA (25%), but rarely (<1%) IgM,IgD, or IgE.

Production of excess light chain is frequent and is excreted in the urine as Bence Jones proteins.

About 20-25% of cases produce only light chains which are often detectable only in the urine.

Fewer than 5% of myelomas are nonsecretory.

I mmunoglobulin filled cytoplasm may invaginate into the nucleus creating the appearance of an intranuclearinclusion (a Dutcher body).

 

 

Excess Ig in the peripheral blood may result in Rouleaux formation in which immunoglobulin coated RBCs cling together (resembling overlapping pennies).

 The ESR may be increased secondary to hyperviscosity.

 

Hyperviscosity is most common with IgM, but can be seen with polymerization of IgA and IgG3.

M-proteins can interfere with clotting factors and fibrin polymerization, and can block aggregation by coating platelets.

roulaux formation

 

In approximately 75% of patients excess immunoglobulin light chain precipitates in renal tubules forming dense tubular casts and leads to tubular cell atrophy and destruction in a condition known as "myeloma kidney".

Although we think of Ig as being in plasma, remember that the majority of Ig is extravascular.

 

In about10% of myeloma patients a waxy substance known as amyloid is deposited in vessel walls and extravascular tissues secondary to excess light chain (usually l) production.

Amyloid stains lightly eosinophilic with H&E, red-orange with Congo Red, and is birefringent when polarized.

Amyloid stained with Congo red.

Polarized birefringent amyloid.

 

The EM appearance of amyloid is that of a mass of nonbranching linear fibrils of indeterminant length, 7-10 nm dia.

Accumulation of amyloid primarily in glomeruli, but also in vessels and interstium is a major cause of renal failure and death.

Heart failure is 2' to amyloid deposition in the conduction system.

GI tract infiltration can cause macroglossia, hemorrhage, malabsorption, diarrhea, and obstruction. Vascular damage results in amyloid purpura of the face (eyelids & periorbital tissue), neck and chest. Soft tissue accumulation may lead to the carpal tunnel syndrome.

 

The major diagnostic criteria for myeloma (any two are needed for the diagnosis) include:

- bone marrow plasmacytosis of > 30% of all marrow cells or masses of infiltrating plasma cells

- extraosseous plasmacytoma

- monoclonal gammopathy ( IgG > 35 g/L and IgA > 20 g/L )

- urinary light chain excretion of > 1g / 24 hours

Minor criteria (one or more of which together with one major criteria are needed for the diagnosis) include

- marrow plasmacytosis of < 30%

- lytic bone lesions

- evidence of a monoclonal protein but lessor amounts than above

- hypoglobulinemia of normal proteins

The prognosis for myeloma is highly variable, but left untreated, most patients survive only 6-18 months. Survival correlates with the extent of disease at diagnosis.

Myeloma Staging

Stage I

Stage II

Stage III

all criteria must be meet

-Hgb >100g/L

-normal serum Ca

-normal bone X-ray or

single bone plasmacytoma

-sm amounts of monoclonal Ig

-IgG < 50g/L

-IgA < 30g/L

-urine light chain<4g/24hr

low myeloma cell mass

neither Stage I or II

intermediate myeloma cell mass

one or more criteria needed

-Hgb < 85g/L

-serum Ca > 12mg/dL

-multiple lytic bone lesions

-large amounts of monoclonal Ig

-IgG > 70g/L

-IgA > 50g/L

-urine light chain>12g/24hr

high myeloma cell mass

Median survival is approximately 6.5 years for stage I myeloma; 5 years for stage II myeloma, and 2 years for stage III myeloma.

 

b2 macroglobulin is another prognostic factor that is predictive of prognosis: levels greater than 6mg corresponding to stage II or III disease.

The presence of amyloid, an IgA M-protein, or CD10 + myeloma cells are poor prognositic factors.

During the early stages of myeloma, especially in asymptomatic patients, the doubling time is long and growth slow, thus initially one may forego treatment.

Classic myeloma requires treatment for pain, hypercalcemia, renal failure or anemia. Although no curative therapy exists, a number of theraputic modalities are available. While surgery and radiotherapy play a role in treatment of spinal cord compression and pathologic fractures, chemotherapy is the primary basis of therapy. Standard chemotherapy is remains prednisone and L-phenylalanine mustard (Alkeran) or melphalan. Supportive therapy for dealing with hypercalcemia, infection, and hyperviscosity is essential to good patient care.

Death is most often secondary to infection or renal failure.

 

·        Multiple myeloma is a diffuse disease of the bone marrow. Almost 90% of patients with myeloma have osseous involvement. Although any bone can be affected, 4 distinct radiographic patterns of involvement are seen, including (1) normal bone mineralization without a discrete lytic lesion, (2) diffuse demineralization and no lytic lesion, (3) a single lesion (plasmacytoma), and (4) widespread lytic lesions.

·        The predominant sites of involvement are within the axial skeleton and include the vertebral column, ribs, skull, pelvis, and femora. Most patients have either a number of lytic foci or diffuse demineralization at diagnosis. Fewer than 10% of patients with multiple myeloma are diagnosed with only a plasmacytoma found on radiography. Interestingly, extraosseous myeloma deposits occasionally are found, most commonly in the lungs, nasopharynx, or paranasal sinuses.

·        Clinical Details: The underlying pathology of multiple myeloma is expansion of a single line of plasma cells that replace normal bone marrow and produce monoclonal immunoglobulins. As a result, in more than 80% of patients, the disease manifests with bone destruction and pain. Since bone loss occurs mostly in the axial skeleton, patients with myeloma are at risk for compression fractures of the spine and pathologic fractures of the major weight-bearing bones of the body.

·        The classic presentation is low back pain in an older man, with resultant discovery of demineralization or a myelomatous deposit. The classic presentation has dropped to a frequency of 37% from a high of almost 70% in the 1960s, which may be related to increased surveillance for other diseases and the incidental discovery of myeloma or may be a result of increased awareness of the nonclassic manifestations of the disease.

·        Patients with myeloma develop disorders relating to replacement of myelogenous marrow by plasma cells. In particular, anemia is a primary manifestation of the disease (>90% of patients). Patients also may develop frequent unexplained infections resulting from an inability to mount an immune response by normal plasma cells (decreased in number by the favored production of malignant myeloma cells). Generalized weakness resulting from anemia is a frequent finding, as are the neurologic symptoms believed to be related to disruption in calcium homeostasis. More than 40% of patients with myeloma develop weight loss related to their disease. Finally, as many as 13% of myeloma patients have bleeding disorders, mostly related to low platelet production.

·        The diagnostic laboratory finding in myeloma is monoclonal hypergammaglobulinemia. IgG myeloma is the most common, followed by IgA myeloma. As a result of bone destruction, hypercalcemia is a common manifestation and can be difficult to manage. Other laboratory abnormalities include hyperuricemia (resulting from elevated cell turnover), elevated sedimentation rate, and increased levels of alkaline phosphatase.

·        Renal disorders are a common manifestation of multiple myeloma. Myeloma cells produce large numbers of proteins. Fragmentation of some of these immunoglobulins produces a special protein (ie, Bence-Jones protein) that was elucidated in the original description of the disease. This protein, as well as others produced by the malignant plasma cells, may be deposited in the kidney tubules. The proteinemia in myeloma often exceeds the resorptive ability of the kidney, resulting in proteinuria, and in particular, spillage of Bence-Jones protein. In addition, amyloidosis is a frequent finding (8-15%) in patients with myeloma and further contributes to parenchymal dysfunction. Calculi often are found because of elevated uric acid and calcium levels. All of these factors eventually can result in renal failure and death.

The unequivocal diagnosis of myeloma is made when the following 3 criteria are satisfied:

  • A minimum of 10-15% of a bone marrow aspirate demonstrating plasma cells
  • Radiographic survey demonstrating lytic lesions
  • Monoclonal immunoglobulins in the urine or blood

Note that as many as 37% of cases currently are discovered in asymptomatic patients. Most commonly, examination of the blood for an unrelated reason reveals an elevated protein level and leads to the eventual diagnosis of myeloma. These patients may not always meet all 3 diagnostic criteria. Other laboratory studies have been proposed to provide an unequivocal diagnosis of myeloma, including the use of special stains and the detection of nuclear abnormalities. Beta-2 microglobulin has been shown to be the peripheral marker most associated with activity and progression of disease.

Preferred Examination: The preferred initial radiographic examination for both the staging and diagnosis of myeloma remains the skeletal survey. Patients suspected of having multiple myeloma based on bone marrow aspirate or hypergammaglobulinemia should undergo a radiographic skeletal survey. Conventionally, the survey has consisted of a lateral radiograph of the skull, anteroposterior and lateral views of the spine, and anteroposterior views of the pelvis, ribs, femora, and humeri. Inclusion of these bones is important for both staging and diagnosis.

The finding of more than one lytic lesion in a patient with myeloma indicates stage III disease. Focused examinations of newly painful bones are of value in assessing for impending pathologic fracture.

Limitations of Techniques: The skeletal survey has limitations. Most importantly, a large number of patients diagnosed with asymptomatic myeloma may have radiographically occult myeloma deposits. At least 30% cortical bone loss is required to visualize a destructive process, such as myeloma, with radiographs. In addition, myeloma is a disease of older patients. Myeloma can present with diffuse demineralization, which may be indistinguishable from the pattern found in patients with osteoporosis.

MRI has been suggested as an additional imaging examination in patients with myeloma. MRI has the advantage of rapidity and sensitivity for the presence of disease; however, specificity is limited. Recent papers have suggested that an MRI examination of the spine may be of value in staging patients with myeloma, since radiographically occult lesions may be found that can change therapeutic intervention

 

 

Cellular Classification

Diseases associated with an M-protein included in this presentation are:

1. Asymptomatic plasma cell neoplasia with minimal evidence of disease aside from the presence of an M-protein (monoclonal gammopathy of undetermined significance, or MGUS).1

2. Symptomatic plasma cell neoplasia

a. primarily affecting bones

i. multiple myeloma (94%)

ii. solitary plasmacytoma (3%)

b. extramedullary plasmacytoma (3%)

These usually occur in the nasopharynx, tonsils, or paranasal

sinuses.2

3. Macroglobulinemia. Patients often have lymphadenopathy and hepatosplenomegaly; less than 5% have lytic bone lesions.

a. asymptomatic

b. symptomatic

Monoclonal (M) "spikes" usually occur in either the b or g regions.

 An individual plasma cell produces only one type of light chain, either k or l light chain, but never both.

 In plasma cell disorders a clone of cells produces a single light chain type, either k or l .

In plasma cell disorders a clone of cells produces a single light chain type, either k or l . If the clone is large enough, sufficient immunoglobulin is produced to be visible as a "spike" on gel electrophoresis, identifying a monoclonal population of cells.

Nearly all malignant cell populations are monoclonal, where as nearly all reactive populations are polyclonal.

In a reactive state, antigen is presented to multiple lymphocytes each of which will make a slightly different antibody. Some lymphocytes/plasma cells will make k light chains and some will make l light chains. Even among all the l producing cells, most individual cells each make a slightly different antibody, producing increased amounts of heterogeneous immunoglobulins, or a (polyclonal gammopathy).

 

 

The key favorable prognosticators for the durations of complete remission, event-free survival, and overall survival:

  • absence of "unfavorable karyotopes" (on chromosome 13)
  • low levels of beta-2-microglobulin
  • no more than 1 year of prior myeloma therapy

Autologous transplantation is considered feasible and safe in patients > 65 years.

 

Systemic Therapy Options in Myeloma

  • Oral alkylating agents±corticosteroids
    e.g. melphalan or cyclophosphamide
  • High dose corticosteroids
    Multiagent regimens
    e.g VAD, PCAB, ABCM, VBMCP/VBAP
  • Interferon alpha - alone or in combination with chemotherapy
  • High dose therapy with stem cell support - autologous or allogeneic
  • New/investigational
    thalidomide
    immune therapies

 

Idiotypic myeloma cells can be found in the blood of myeloma patients in all stages of the disease.1,2 For this reason, when treatment is indicated, systemic chemotherapy must be considered for all patients with symptomatic plasma cell neoplasms. Patients with monoclonal gammopathy of undetermined significance (MGUS) or asymptomatic, smoldering myeloma do not require immediate treatment, but must be followed carefully for signs of disease progression.

Patients with an M-protein in the serum and/or urine are evaluated as follows:

1. Measure and follow the serum M-protein by serum electrophoresis. The M-protein can also be followed by specific nephelometry immunoglobulin assays, however, these assays always overestimate the M-protein because normal immunoglobulins are included in the result. For this reason, baseline and follow-up measurements of the M-protein should be done by the same method.3

2. Measure and follow the amount of M-protein light chains excreted in the urine per 24 hours. First, measure the total amount of protein excreted per 24 hours and multiply this value by the percentage of urine protein that is M-protein, as determined by electrophoresis of concentrated urine protein.

3. Identify the heavy- and light-chain of the M-protein by immunofixation.

4. Measure the hemoglobin, leukocyte, platelet, and differential counts.

5. Determine the percentage of marrow plasma cells. More than one site may need to be sampled because marrow plasma cell distribution tends to be spotty.

6. Take needle aspirates of a solitary lytic bone lesion, extramedullary tumor(s), or enlarged lymph node(s) to determine whether these are plasmacytomas.

7. Evaluate renal function with serum creatinine and a creatinine clearance. Electrophoresis of concentrated urine protein is very helpful in differentiating glomerular lesions from tubular lesions. Glomerular lesions, such as those resulting from glomerular deposits of amyloid or light chain deposition disease, result in the non-selective leakage of all serum proteins into the urine; the electrophoresis pattern of this urine resembles the serum pattern. In most myeloma patients the glomeruli function normally, allowing only the small molecular weight proteins, such as albumin and light chains, to filter into the urine. In the tubules the concentration of protein increases as water is reabsorbed. This leads to precipitation of proteins and the formation of tubular casts, which may injure the tubular cells. With tubular lesions, the typical electrophoresis pattern shows a small albumin peak and a larger light chain peak in the globulin region; this tubular pattern is the usual pattern found in myeloma patients.

8. Measure serum levels of calcium, alkaline phosphatase, lactic dehydrogenase, and, when indicated by clinical symptoms, cryoglobulins and serum viscosity.

9. Obtain radiographs of the skull, ribs, vertebrae, pelvis, shoulder girdle, and long bones.

10. Perform magnetic resonance imaging (MRI) if a paraspinal mass is detected, or if symptoms suggest spinal cord or nerve root compression.

11. If amyloidosis is suspected, do a needle aspiration of subcutaneous abdominal fat and stain the bone marrow biopsy for amyloid as the easiest and safest way to confirm the diagnosis.4

12. Measure serum albumin and beta-2 microglobulin as useful, independent prognostic factors.5,6

13. The marrow plasma cell labeling index, the serum soluble IL-6 receptor, and the number of circulating myeloma cells are under evaluation as prognostic factors.7

These initial studies should be compared with subsequent values at a later time, when it is necessary to decide whether the disease is stable or progressive, responding to treatment or getting worse. The major challenge is to separate the stable asymptomatic group of patients, who do not require treatment, from patients with progressive, symptomatic myeloma who should be treated immediately.

Patients with MGUS have an M-protein in the serum and/or urine and fewer than 10% plasma cells in the marrow, but no other signs or symptoms of disease. Those with smoldering myeloma have similar characteristics, but may have more than 10% marrow plasma cells. Since 1% of MGUS patients will progress per year to develop myeloma (most commonly), amyloidosis, a lymphoma, or chronic lymphocytic leukemia, these patients must be followed carefully.8 Treatment is delayed until the disease progresses to the stage that symptoms or signs appear. Patients with MGUS or smoldering myeloma do not respond more frequently, achieve longer remissions or improved survival if chemotherapy is started early, while they are still asymptomatic, as opposed to waiting for progression before treatment is initiated.9

Treatment options for patients with symptomatic myeloma range from relatively simple conventional chemotherapy to high-dose chemotherapy and peripheral stem cell or allogeneic bone marrow transplantation. Treatment choice is determined largely by the age and general health of the patient and should be finely attuned to the preferences of patients and their families.

 

Conventional chemotherapy treatment options

Chemotherapy prolongs the survival of patients with symptomatic myeloma to a median of 40 to 46 months for patients with stage I disease, 35 to 40 months for patients with stage II disease, and 24 to 30 months for patients with stage III disease.

A well-tolerated chemotherapy regimen producing consistent results is melphalan and prednisone (MP

Other regimens appear to produce similar survival outcomes. They are: 1. VAD: vincristine + doxorubicin + dexamethasone

2. High-dose dexamethasone

3. Cyclophosphamide + prednisone

4. VBMCP (the M2 protocol): vincristine + carmustine + melphalan + cyclophosphamide + prednisone

5. VMCP/VBAP: vincristine + melphalan + cyclophosphamide + prednisone alternating with vincristine + carmustine + doxorubicin + prednisone

·        A randomized, double-blind study of patients with stage III myeloma showed that monthly intravenous pamidronate significantly reduces pathologic fractures, bone pain, spinal cord compression, and the need for bone irradiation (there were 38% skeletal-related events in the treated group versus 51% in the placebo group after 21 months of therapy, p=.015).[Level of evidence: 1iDii] In addition, survival was increased (median survival was 21 months versus 14 months) in the patients receiving pamidronate and second line or greater chemotherapy.

·        There is no strong evidence that any alkylating agent is superior to another. All standard doses and schedules produce equivalent results. However, the absorption and metabolism of some alkylating agents require special attention. Melphalan is absorbed erratically from the gastrointestinal tract, and food interferes with this absorption. For this reason, melphalan should be administered on an empty stomach, e.g., 1 hour before breakfast. (Food does not interfere with the absorption of prednisone, which is often given with breakfast.) The clearance of melphalan from the blood stream is delayed in patients with renal failure, leading to increased toxic effects; the initial dose of melphalan should be reduced in patients with a serum creatinine greater than 2.0 milligrams per deciliter. Cumulative hematologic toxic effects tends to develop with repeated courses of melphalan. If slow hematologic recovery prevents repeating a course of melphalan at 6 to 7 week intervals, consideration should be given to switching to cyclophosphamide, which allows more rapid marrow recovery.

·        Because melphalan is absorbed so erratically, the dose should be increased until mild hematologic toxic effects, or a response, is observed. In patients with normal renal function, the usual starting dose is 0.25 milligrams per kilogram per day for 4 days, repeated at 4 to 6 weeks. If no hematologic toxic effects or response is observed, the dose should be increased by 2 to 4 milligrams per day for 4 days, and blood counts should be repeated weekly. The dose of melphalan is increased in subsequent courses until mild leukopenia or thrombocytopenia is observed, with recovery in 4 to 6 weeks.

·        Cyclophosphamide, in contrast to melphalan, is absorbed well, and clearance from the blood stream does not influence its toxic effects. Also, the dose of cyclophosphamide does not have to be reduced in patients with renal insufficiency. Cyclophosphamide is less toxic to thrombopoiesis than melphalan, and may be preferred in the treatment of thrombocytopenic patients.

·        Combinations of alkylating agents and prednisone, given simultaneously or alternately, have not proven to be superior to therapy with MP. [Level of evidence: 1iiA] A meta-analysis of studies comparing melphalan plus prednisone with drug combinations concluded that both forms of treatment were equally effective.[Level of evidence: 1iiA] Patients who relapsed after initial therapy with cyclophosphamide and prednisone had no difference in overall survival (median 17 months) when randomized to VBMCP or VAD.

·        Myeloma patients who respond to treatment show a progressive fall in the M-protein until a plateau is reached; subsequent treatment with conventional doses does not result in any further improvement. This has led investigators to question how long treatment should be continued. Three clinical trials considered the role of maintenance therapy; all found no improvement in survival. In a single study,27 it was observed that maintenance therapy with MP prolonged the initial remission duration (31 months) compared to no maintenance treatment (23 months). There was no effect on overall survival, however, because the majority of patients who relapsed in the no maintenance arm responded again to MP, while those on maintenance MP did not respond to further treatment. Most therapists recommend continuing induction therapy for at least 12 months. The Canadian group suggests that induction chemotherapy be continued as long as the M-protein continues to fall; therapy can be discontinued after the M-protein reaches a plateau that remains stable for 4 months.

·        Maintenance interferon alfa therapy has been reported in several studies to prolong initial remission duration. While the impact of interferon maintenance on disease-free and overall survival has significantly varied among trials, a meta-analysis of 1543 patients treated on 12 trials randomizing between interferon maintenance and observation indicated that interferon maintenance was associated with improved relapse-free survival (27% versus 19% at 3 years, p<0.00001) and overall survival (12% odds reduction, p=0.04).32 In this population, toxic effects may be substantial and must be balanced against the potential benefits in response duration.

·        Lytic lesions of the spine should be irradiated if they are associated with an extramedullary (paraspinal) plasmacytoma, if there is painful destruction of a vertebral body, or if there is computed tomography or MRI evidence of spinal cord compression.

·        Back pain caused by osteoporosis and small compression fractures of the vertebrae responds best to chemotherapy. Extensive radiation of the spine or long bones for diffuse osteoporosis may lead to prolonged suppression of hemopoiesis, and is rarely indicated.

·         Bisphosphonates are useful for slowing or reversing the osteopenia that is so common in myeloma patients.

 

High-dose chemotherapy options for symptomatic myeloma

The failure of conventional chemotherapy to cure the disease has led investigators to test the effectiveness of much higher doses of drugs such as melphalan. The development of techniques for harvesting hemopoietic stem cells, from marrow aspirates or the peripheral blood of the patient, and infusing these cells to promote hemopoietic recovery, made it possible for investigators to test very large doses of melphalan. From the experience with thousands of patients treated in this way, it is possible to draw a few conclusions:

1. The risk of early death due to treatment-related toxic effects have been reduced to less than 5%.35 Patients can now be treated as outpatients.

2. High-dose therapy should be reserved for myeloma patients who are still responsive to chemotherapy. Patients with refractory myeloma rarely achieve a complete response to high-dose treatment, and responses are usually brief.36

3. Extensive prior chemotherapy, especially with alkylating agents, compromises marrow hemapoieses and may make the harvesting of adequate numbers of hemopoietic stem cells impossible.

4. After autologous bone marrow transplantation, 84 patients were randomized to receive maintenance interferon or no treatment. [Level of evidence: 1iiA] The interferon group had longer progression-free survival (46 months versus 27 months, p<0.025) and overall survival (75% versus 50%, p<0.01). These results have not been confirmed after peripheral stem cell transplantation.

5. Newly diagnosed patients with progressive disease should be considered candidates for clinical trials of new approaches to treatment. 6. Younger patients in good health tolerate high-dose therapy better than patients with poor performance status.35

The Intergroupe Francais du Myelome randomized 200 previously untreated myeloma patients under 65 years of age to treatment with conventional chemotherapy (alternating courses of VMCP/VBAP) versus high-dose therapy (140 milligrams melphalan per meter squared and total body irradiation, 8 Gy delivered in 4 fractions over 4 days with no lung shielding, followed by autologous bone marrow rescue). Survival and disease-free survival were significantly improved in the high-dose arm (the estimated 5-year survival was 52% versus 12%; the estimated 5-year event-free survival was 28% versus 10%). [Level of evidence: 1iiA] Relapses, however, continue to occur at a constant rate, so that at 5 years, only 28% of those receiving high-dose therapy, and 10% of those on conventional chemotherapy have not relapsed. Event-free survival is significantly better for the high-dose group (p=0.01), but there is no sign of a slowing in the relapse rate, or a plateau, to suggest that any of these patients have been cured. While these data suggest that myeloablative therapy with autologous transplant may prolong survival for patients with multiple myeloma, the finding requires confirmation by the current ongoing intergroup study comparing standard therapy to high-dose options.38 In a prospective randomized trial, 193 patients with multiple myeloma received autologous peripheral stem cell transplantation after high-dose chemotherapy with or without CD34 selection. Although CD34 selection reduced myeloma cell contamination in the stem cell collections, there was no difference in disease-free or overall survival. [Level of evidence: 1iiA]

Improvement in survival following high-dose therapy with autologous stem cell support was also suggested by a Scandinavian study in which all symptomatic newly diagnosed patients with multiple myeloma were registered.41 Patients received induction therapy with VAD, followed by stem cell collection following cyclophosphamide and granulocyte-colony stimulating factor (G-CSF). High-dose therapy consisted of melphalan, 200 milligrams per meter squared, with stem cell and G-CSF support. Patients subsequently received maintenance interferon. The outcome of these patients was compared to that of historic controls who met eligibility criteria for the high-dose therapy trial. Survival appeared superior for the intensively-treated group (risk ratio for the control group 1.62, confidence interval 1.22-2.15, p=0.001). The use of historic controls and lack of complete data on pretreatment beta-2-microglobulin levels may have biased the results in favor of the intensive therapy cohort. [Level of evidence: 3iiiA]

Another approach to high-dose therapy has been the use of 2 sequential episodes of high-dose therapy with stem cell support (so-called "tandem" transplants). In a retrospective analysis of 1000 patients treated at the University of Arkansas for Medical Sciences with melphalan-based "tandem" high-dose therapy, treatment-related mortality was approximately 8% and the complete remission rate was 44%.42 Five-year event-free survival was 25%. The best outcomes occurred in a patient group which would be considered to be relatively "good- risk" for outcome with conventional chemotherapy (low beta-2-microglobulin and C-reactive protein levels; absence of abnormalities of chromosome 13). [Level of evidence: 3iiiDi]

In a registry of 162 patients who underwent allogeneic matched sibling-donor transplants, the actuarial overall survival rate was 28% at 7 years. [Level of evidence: 3iiiA] Favorable prognostic features included low tumor burden, responsive disease before transplant, and application of transplantation after first-line therapy. Many patients are not young enough or healthy enough to undergo these intensive approaches. A definite graft-versus-myeloma effect has been demonstrated, including regression of myeloma relapses following the infusion of donor lymphocytes.

 Allogeneic marrow transplants are too risky to be considered by most patients, but the possibility of a potent, and possibly curative graft-versus-myeloma reaction makes this procedure attractive. Further research is required to make allogeneic transplants less dangerous, and also, perhaps, to find methods for initiating an autoimmune response to the myeloma cells.

 

 

Waldenstrom's Macroglobulinemia (Lymphoplasmacytic Leukemia)

·        Lymphoplasmacytic lymphoma is usually associated with a monoclonal serum paraprotein of immunoglobulin M type (Waldenstrom's macroglobulinemia).

·         Most patients have bone marrow, lymph node, and splenic involvement, and some patients may develop hyperviscosity syndrome. Other lymphomas may also be associated with serum paraproteins.

·        The management of lymphoplasmacytic lymphoma is similar to that of other low-grade lymphomas, especially diffuse small lymphocytic lymphoma/chronic lymphocytic leukemia

·         If the viscosity relative to water is greater than 4, the patient may have manifestations of hyperviscosity. Plasmapheresis is useful for temporary, acute symptoms (such as retinopathy, congestive heart failure, and central nervous system dysfunction), but should be combined with chemotherapy for prolonged control of the disease.

·         Symptomatic patients with a serum viscosity of 4 or less are usually started directly on chemotherapy.

·         Therapy may be required to correct hemolytic anemia in patients with chronic cold agglutinin disease; chlorambucil, with or without prednisone, is the mainstay.

·         Occasionally, a heated room is required for patients whose cold agglutinins become activated by even minor chilling.

·        Asymptomatic patients can be monitored for evidence of disease progression without immediate need for chemotherapy.

·         The nucleoside analogues 2-chlorodeoxyadenosine and fludarabine have shown significant activity for previously untreated patients with lymphoplasmacytic lymphoma.

·         Single-agent alkylators and combination chemotherapy are also active regimens

·         Interferon alfa also shows activity in this disease, in contrast to poor responses in patients with multiple myeloma.

·         Myeloablative therapy with autologous hematopoietic stem cell support is under evaluation.

·         Rituximab, the anti-CD20 monoclonal antibody, is active in 30% of previously treated patients.

Monoclonal Gammopathy of Undetermined Significance

Patients with monoclonal gammopathy of undetermined significance (MGUS) have an M-protein in the serum without symptoms or findings of multiple myeloma, macroglobulinemia, amyloidosis, or lymphoma and with fewer than 10% plasma cells in the bone marrow.1,2 Multiple myeloma, other plasma cell dyscrasia, or lymphoma will develop in 5% of patients by 5 years, 15% by 10 years, and 30% by 15 years. Unfortunately, patients who will eventually develop plasma cell malignancy or lymphoma cannot be identified on the basis of level of M-protein, peripheral blood count, type of monoclonal immunoglobulin, percentage of plasma cells in the bone marrow, or levels of normal immunoglobulins. Therefore, all patients with MGUS must be kept under observation to detect increases in M-protein levels and development of one of the above malignancies.

Refractory Plasma Cell Neoplasm

·        There are two main types of refractory myeloma patients: primary refractory patients who never achieve a response and progress while still on induction chemotherapy; and secondary refractory patients who do respond to induction chemotherapy, but do not respond to treatment after relapse.

·        The primary group may respond to high-dose chemotherapy and autologous stem cell rescue.

·        Of the patients who do not achieve a response to induction chemotherapy, a subgroup of about 10% have stable disease and enjoy a survival prognosis that is as good as that for responding patients.

·         When the stable nature of the disease becomes established, these patients can discontinue therapy until the myeloma begins to progress again. Others with primary refractory myeloma and progressive disease require a change in therapy; the choices have been reviewed.

·        A preliminary report on thalidomide suggests anti-tumor activity with minimal hematologic toxic effects.6 Further clinical trials are underway.

·        For patients who respond to their initial therapy, the myeloma growth rate, as measured by the M-protein doubling time, increases progressively with each subsequent relapse and remission durations become shorter and shorter. Marrow function becomes increasingly compromised as patients develop pancytopenia and enter a refractory phase; occasionally the myeloma cells dedifferentiate and extramedullary plasmacytomas develop. The myeloma cells may still be sensitive to chemotherapy, but the regrowth rate during relapse is so rapid that progressive improvement is not observed. At this stage of the disease, high-dose glucocorticoids may be the best approach.7,8 High-dose chemotherapy with growth factor support is being evaluated in these refractory situations.9 Less myelosuppressive regimens can also be used as second- or third-line therapy

Immunosecretory Disorders: Other PCD

"Nonsecretory" myeloma in which immunoglobulin is not synthesized (true nonsecretory) or secreted but not excreted, is rare (<5%). Cases have been reported in which there is production of J chain but no heavy or light chain.

Clinical, hematologic, and radiologic findings are similar to those of standard myeloma. Some have reported fewer problems with infection and less renal damage (no increase in circulating monoclonal immunoglobulin) but survival appears no better than the average myeloma patient.

Plasmacytoma (<1% of monoclonal gammopathies) is a solitary clonal mass of plasma cells - either bone or soft tissue. About 25% of cases are associated with an M spike. Bone lesions usually progress to multiple myeloma. Extraosseous lesions rarely spread and can be surgically excised.

 

 

Immunosecretory Disorders: MGUS

Plasma cell leukemia (plasma cells >2.0x109/L) can be either a primary or a terminal finding in myeloma. Treatment is with aggressive chemotherapy.

 

 

 

·        Monoclonal gammopathy of unknown significance (MGUS) is an asymptomatic disorder in which a monoclonal immunoglobulin is secreted by a fairly stable clone of plasma cells. MGUS is sometimes referred to as dysproteinemia without associated disease. The incidence of MGUS increases with age (1% at age 50 years; 5% at age 70 years; 10% at age 80 years). Approximately 10% of patients with MGUS will develop myeloma within 5 years. Almost 20% will develop a malignant PCD (myeloma, WM, amyloidosis, and ML) within 10 years.

·        The M protein of MGUS is < 30 g/L, usually IgG, but occassionally IgA or IgM, and without a Bence-Jones protein.

·        Bone marrow biopsy and aspirate show a mild increase in plasma cells, but no mass lesion.

 

 

Immunosecretory Disorders: Waldenstrom's

 

 

·        Waldenstrom's macroglobulinemia (WM) or primary macroglobulinemia (7% of monoclonal gammopathies) is a malignant proliferation of plasmacytoid lymphocytes corresponding to activated B lymphocytes.

·        The lymphocytes, plasmacytoid lymphocytes, and plasma cells diffusely infiltrate the bone marrow, lymph nodes, spleen, and liver (but not forming tumor masses, nor lytic lesions as does myeloma). WM is associated with ML, small lymphocytic type. "Flame" cells and Dutcher bodies are more likely to be encountered in WM than in other plasma cell disorders. Mast cells,

·        while accompaning many lymphoproliferative disorders are especially numerous and characteristic of Waldenstrom's.

·        The malignant cells secrete a monoclonal IgM protein which causes a macroglobulinemia. The large size of the IgM complexes or paraproteins

·        increases blood viscosity. Hyperviscosity results in neurologic, visual, and bleeding complications. Cryoglobulins can be seen in WM giving rise to Raynaud's phenomemon.

·        Waldenstrom's is a slowly progressive disorder, with survival of 2-5 years and longer, that most commonly presents in the sixth and seventh decades. Vague symptoms of weakness, weight loss and a mild bleeding tendency, often many years before diagnosis, are usually the first evidence of disease. Later lymphadenopathy and hepatosplenomegaly become prominent. In general, the clinical course is similar to that of chronic lymphocytic leukemia.

·        Although not curable, chemotherapy (alkalating agents ie. melphahan) can stay the disease. Plasmapheresis is also useful to quickly remove IgM from the plasma, lowering viscosity and improving blood flow.

 

 

Immunosecretory Disorders: Cryoglobulins

 

 

·        Cryoglobulinemia results from abnormal proteins that precipitate at reduced temperatures. It is associated with PCDs and chronic inflammation. Cryoglobulins can be 1) monoclonal immunoglobulins (Type I) as in myeloma or Waldenstrom's, 2) monoclonal proteins (usually IgM k) complexed to IgG (Type II), or 3) polyclonal immune complexes with no monoclonal component (Type III). Types II and III are associated with connective tissue and autoimmune disorders. Through the formation of protein gels at reduced body temperatures, precipitated cryoglobulins can occlude small vessels giving rise to Raynaud's phenomemon, vascular purpura (cold urticaria) and arthralgia.

·        Therapy is based on the treatment of the underlying disease and/or plasmapheresis and, of course, avoidance of cold.

·        Note that cold agglutinins which are RBC antibodies are different from cyroglobulins.

 

 

Immunosecretory Disorders: Heavy Chain Disease

 

 

·        Heavy chain disease (HCD) is a group of very rare PCDs producing excessive amounts of a monoclonal heavy chain, but no light chain. Monoclonal production of each of the major immunoglobulin heavy chain classes results in a different clinical presentation.

·        Alpha chain disease, also known as Mediterranean lymphoma is the most common of the HCDs. It is most often seen in young adults from the Mediterranean area. The lamina propria of the intestinal mucosa and abdominal lymph nodes are infiltrated by lymphocytes, plasmacytoid lymphocytes, and plasma cells producing a chain proteins. The lymphoid infiltrate of the lamina propria of the intestinal mucosa results in villous atrophy, malabsorption, steatorrhea, diarrhea, and hypocalcemia. An abdominal mass of lymphoid tissue is often present. Serum a chains must be demonstrated for the diagnosis.

·        Presenting symptoms are most often abdominal pain, diarrhea, and malabsorption. In time a HCD may progress to a large cell B - immunoblastic lymphoma. Survival is variable from a few months to several years.

·        Gamma chain disease (g HCD) most commonly presents as lymphadenopathy, hepatosplenomegaly, anemia and fever. Although reported as most common in elderly patients g HCD can occur in patients < 20 years of age. No lytic bone lesions are present but plasmacytoid lymphocytes, plasma cells, eosinophils and histiocytes diffusely infiltrate the marrow and lymph nodes.

·        As many as one third of g HCD patients have an associated autoimmune disease including AIHA, Sjogren's syndrome, rheumatoid arthritis, SLE, thyroiditis, etc.

·        As with a HCD, survival in g HCD varies greatly from months to years. Death is most often secondary to infection.

·        Mu chain disease (m HCD) is the least common form of HCD. It is often associated with chronic lymphocytic leukemia (CLL) or with a disease similar to CLL in which there are large numbers of circulating lymphocytes. Marrow plasma cells are characteristically vacuolated. Hepatosplenomegaly is common as a presenting symptom, but without accompaning lymphadenopathy. Excess m chains are present in the peripheral blood and k light chains sometimes found in the urine.

·        Chemotherapy is similar to that used for CLL.

·        Chronic lymphocytic leukemia is occassionally (<10% of CLL) accompanied by a monoclonal protein (<2% of monoclonal gammopathies).

 

 

 

 

Immunosecretory Disorders: Amyloidosis

 

 

Amyloidosis is a syndrome in which proteins with a b pleated sheet secondary structure accumulate in tissues. Amyloid stains lightly eosinophilic with H&E, metachromatic with crystal violet. The b pleated sheet structure causes a green birefringence when Congo red stained material is polarized. Amyloid fibrils containing a part of the variable region of the light chain are labeled AL. Amyloid fibrils containing amyloid A, a protein derived from an acute phase reactant are called protein AA.

Amyloid fibrils consist of two paired filaments,creating a parallel array. This imposes a regular parallel order to the molecules of Congo red dye,causing polarization of light and the birefringentproperties characteristic of amyloid

.

 

Primary amyloidosis (AL) is associated with PCDs (M proteins) and idiopathic causes, where as secondary amyloidosis (protein AA) is associated with chronic inflammation and arthritis and while there may be proteinuria, no monoclonal protein is seen.

Amyloid infiltrates cause organ damage resulting in failure as in the nephrotic renal syndrome. Heart failure can be seen secondary to amyloid deposition in the cardiac conduction system. GI tract infiltration can cause macroglossia, hemorrhage, malabsorption, diarrhea, and obstruction. Vascular damage results in amyloid purpura of the face (eyelids & periorbital tissue), neck and chest. Soft tissue accumulation may lead to the carpal tunnel syndrome and to shoulder "pads" virtually diagnostic of amyloidosis.

Classifications of Amyloidosis

Clinical
Classification

Associated Condition

Amyloid Fibril
Type

Precursor


Systemic Amyloidosis

 

 

Primary or
Secondary

Multiple myeloma

AL

Iglambda
(or kappa chains)

Secondary

Chronic inflammatory disease
__Rheumatoid arthritis
__Tuberculosis
__Skin and lung abscesses

AA

SAA

Secondary

Cancer
Hodgkin's disease

AA

SAA

Secondary

Hemodialysis for CRF(*)

beta2-m(**)

beta2-m

Primary

Heredofamilial amyloidosis
__Familial Mediterranean
__Fever
__Familial amyloid
__polyneuropathy

AA


Transthyretin

SAA


Transthyretin(#)

Localized Amyloidosis</TD< tr>

 

 

 

Senile cardiac amyloidosis

Transthyretin

Transthyretin

 

Senile cerebral amyloidosis:
__Alzheimer's disease

Amyloid beta protein

Amyloid precursor protein (APP)

 

Endocrine tumors
__Medullary carcinoma
__of thyroid

Procaltitonin

Calcitonin


(*): chronic renal failure; (**): beta2-microglobulin is a normal serum protein and a component of MHC class I molecules; (#): transthyretin is a normal serum protein that transports thyroxin and retinol (vitamin A) and is deposited in a variant form.

Amyloidosis Related to Monoclonal Ig Light Chains. AL amyloid is derived from monoclonal Ig light chains, usually of lambda type, produced by abnormal clones of Ig-secreting plasma cells (B cells) AL type of amyloidosis may be primary or may occur secondary to multiple myeloma or some other monoclonal gammopathy (immunocyte dyscrasia). It is the most common type of amyloidosis seen in the U.S. today.

AL type of amyloidosis occurs in about 5-10% of patients who have preexisting or coexisting multiple myeloma. Multiple myeloma is seen mainly in patients over 40 years of age (median age of 60 years) and, next to metastatic carcinoma, is the most common malignant tumor of bone. It is a malignant tumor of plasma cells which arises in the bone marrow, permeates the medullary cavity, erodes the bone cortex, and is characterized by multiple osteolytic ("punched out") lesions of vertebrae, skull, ribs, pelvis, and other bones and by narrow-banded electrophoretic peaks of monoclonal IgG (less commonly IgA , rarely IgD or IgE) in the serum and free light chains of the same kappa or lambda type in the urine (Bence-Jones proteinuria). An identical, patient-specific, free monoclonal light chain protein is also usually present in myeloma serum but, being smaller than albumin molecules, readily passes into the urine. Overall, about 70% of myeloma patients have both serum monoclonal Ig and urinary light chains, and the remaining patients have urinary light chains alone without serum monoclonal Ig.

The AL fibrils are derived from circulating light chains by proteolytic cleavage and conversion to an insoluble form. The organ distribution of AL deposits is usually generalized (systemic) and conforms to either the primary or secondary patterns previously noted.

AL type of amyloidosis is also associated with some other rare monoclonal gammopathies (plasma cell/B immunocyte dyscrasias), such as solitary myeloma (of bone or soft tissue), Waldenstrom's macroglobulinemia, or heavy chain disease in which there are also sometimes an increased production of free light chains that become deposited as amyloid.

Noteworthy, the majority of patients who develop AL type of amyloidosis apparently do so in the absence of clinically overt myeloma or other predisposing disease, and such cases are commonly referred to as primary or idiopathic amyloidosis. Nevertheless, in long term follow up, a substantial proportion of these patients do manifest overt, monoclonal Ig-producing plasma cell or lymphoid cell dyscrasias, such as myeloma, macroglobulinemia, or lymphoma.

Amyloidosis Associated with Inflammatory or Infectious Diseases. The amyloid deposits in this form of amyloidosis have a systemic distribution and contain AA (amyloid-associated) fibrils which are related to the nonimmunoglobulin AA protein and its serum protein precursor (SAA), an acute phase reactant synthesized by hepatic cells. Also called reactive or secondary amyloidosis, this form of amyloidosis occurs mainly as a complication of long standing inflammatory diseases, most frequently rheumatoid arthritis (Å 5-10% of rheumatoid patients) and also dermatomyositis, scleroderma, regional enteritis, and ulcerative colitis.

Prior to the antibiotic era, chronic tissue-destructive infectious diseases, such as tuberculosis, chronic osteomyelitis, and bronchiectasis, were the most common antecedants of secondary amyloidosis. Now, amyloidosis often develops as a complication of skin and lung abscesses occurring in subcutaneous heroin abusers.

Reactive-type amyloidosis may also occur in association with cancer, such as Hodgkin's disease and renal cell carcinoma.

Other Amyloids and Disease Associations.

  1. Amyloid associated with hemodialysis (AH). The systemic amyloid deposition of beta2-microglobulin (beta2-m), a normal serum protein, occurs as a complication of long-term dialysis in patients with chronic renal failure because this protein does not pass through conventional dialysis membranes.
  2. Amyloid associated with familial Mediterranean fever. The systemic deposition of AA fibrils occurs in familial Mediterranean fever, an autosomal recessive disorder seen in individuals of Sephardic Jewish, Armenian, and Arabic descent.
  3. Amyloid associated with familial amyloid neuropathies (AF). Amyloid deposition of a mutant form of transthyretin, a normal serum protein that transports thyroxin and retinol (vitamin A), occurs in peripheral nerves in familial amyloid polyneuropathy, an autosomal dominant disorder occurring in different parts of the world (Sweden, Portugal, Japan, and the U.S.).
  4. Localized deposits of amyloid.

Endocrine-related. Localized amyloid deposits are associated with hormones produced by certain endocrine tumors and endocrine glands, such as medullary carcinoma of the thyroid gland (procalcitonin), islet cell tumors of the pancreas, and the islets of Langerhans (islet associated polypeptide, IAPP) in patients with type II diabetes mellitus.

Age-related. Amyloid deposits of transthyretin occur in the heart of elderly patients with senile cardiac amyloidosis. Beta amyloid protein is deposited in the cerebral blood vessels and plaques of patients with senile cerebral amyloidosis and Alzheimer's disease.

Formation and deposition of AL and AA amyloid.

 

 

 

Immunosecretory Disorders: Summary

 

 

In summary, plasma cell disorders are malignant proliferations of

B lymphocyte origin. Although the terminally differentiated cell is the cell we observe, immunologic and molecular genetic studies indicate that the disorders arise in genetic events at an early stage in B cell development.

The infiltrating cells are lymphocytes, plasmacytoid lymphocytes, and plasma cells producing monoclonal immunoglobulin proteins. The effects of both the mass of cells and the excess immunoglobulin protein determine the nature of the individual diseases. Thus the disease course can range from an asymptomatic disease to a rapidly progressive fatal illnesses.

Despite advances in chemotherapy the plasma cell disorders remain incurable.

 


 

Immunoglobulins (Ig) are antibodies. There are five major classes of antibodies: IgG, IgM, IgA, IgD, and IgE.

  IgG is the most abundant of the classes of immunoglobulins. It is the antibody for viruses, bacteria, and antitoxins. It is found in most tissues and plasma.

  IgM is the first antibody present in an immune response.

  IgA is an early antibody for bacteria and viruses. It is found in saliva, tears, and all other mucous secreations.

  IgD activity is unknown.

  IgE is present in the respiratory secretions. It is an antibody for parasitic diseases, Hodgkin's disease , hay fever, atopic dermatitis , and allergic asthma ).

All antibodies are made by B-lymphocytes (B-cells). Any disease that harms the development or function of B-cells will cause a decrease in the amount of antibodies produced. Since antibodies are essential in fighting infectious diseases, people with immunoglobulin deficiency syndromes become ill more often. However, the cellular immune system is still functional, so these patients are more prone to infection caused by organisms usually controlled by antibodies. Most of these invading germs (microbes) make capsules, a mechanism used to confuse the immune system. In a healthy body, antibodies can bind to the capsule and overcome the bacteria's defenses. The bacteria that make capsules include the streptococci, meningococci, and Haemophilus influenzae. These organisms cause such diseases as otitis, sinusitis , pneumonia , meningitis , osteomyelitis , septic arthritis, and sepsis . Patients with immunoglobulin deficiencies are also prone to some viral infections, including echovirus, enterovirus, and hepatitis B . They may also have a bad reaction to the attenuated version of the polio virus vaccine.

There are two types of immunodeficiency diseases: primary and secondary. Secondary disorders occur in normally healthy bodies that are suffering from an underlying disease. Once the disease is treated, the immunodeficiency is reversed. Immunoglobulin deficiency syndromes are primary immunodeficiency diseases, occurring because of defective B-cells or antibodies. They account for 50% of all primary immunodeficiencies, and they are, therefore, the most prevalent type of immunodeficiency disorders.

  X-linked agammaglobulinemia is an inherited disease. The defect is on the X chromosome and, consequently, this disease is seen more frequently in males than females. The defect results in a failure of B-cells to mature. Mature B-cells are capable of making antibodies and developing "memory," a feature in which the B-cell will rapidly recognize and respond to an infectious agent the next time it is encountered. All classes of antibodies are decreased in agammaglobulinemia.

  Selective IgA deficiency is an inherited disease, resulting from a failure of B-cells to switch from making IgM, the early antibody, to IgA. Although the B-cell numbers are normal, and the B-cells are otherwise normal (they can still make all other classes of antibodies), the amount of IgA produced is limited. This results in more infections of mucosal surfaces, such as the nose, throat, lungs, and intestine.

  Transient hypogammaglobulinemia of infancy is a temporary disease of unknown cause. It is believed to be caused by a defect in the development of T-helper cells (cells that recognize foreign antigens and activate T- and B-cells in an immune response). As the child ages, the number and condition of T-helper cells improves and this situation corrects itself. Hypogammaglobulinemia is characterized by low levels of gammaglobulin (antibodies) in the blood. During the disease period, patients have decreased levels of IgG and IgA antibodies. In lab tests, the antibodies that are present do not react well with infectious bacteria.

  Common variable immunodeficiency is a defect in both B cells and T-lymphocytes. It results in a near complete lack of antibodies in the blood.

  Ig heavy chain deletions is a genetic disease in which part of the antibody molecule isn't produced. It results in the loss of several antibody classes and subclasses including most IgG antibodies and all IgA and IgE antibodies. The disease occurs because part of the gene for the heavy chain has been lost.

  Selective IgG subclass deficiencies is a group of genetic diseases in which some of the subclasses of IgG are not made. There are four subclasses in the IgG class of antibodies. As the B-cell matures, it can switch from one subclass to another. In these diseases there is a defect in the maturation of the B-cells that results in a lack of switching.

  IgG deficiency with hyper-IgM is a disease that results when the B-cell fails to switch from making IgM to IgG. This produces an increase in the amount of IgM antibodies present and a decrease in the amount of IgGaantibodies. This disease is the result of a genetic mutation.

  Causes & symptoms

Immunoglobulin deficiencies are the result of congenital defects affecting the development and function of B lymphocytes (B-cells). There are two main points in the development of B-cells when defects can occur. First, B-cells can fail to develop into antibody-producing cells. X-linked agammablobulinemia is an example of this disease. Secondly, B-cells can fail to make a particular type of antibody or fail to switch classes during maturation. Initially, when B-cells start making antibodies for the first time, they make IgM. As they mature and develop memory, they switch to one of the other four classes of antibodies. Failures in switching or failure to make a subclass of antibody leads to immunoglobulin deficiency diseases. Another mechanism which results in decreased antibody production is a defect in T-helper cells. Generally, defects in T-helper cells are listed as severe combined immunodeficiencies.

Symptoms are persistent and frequent infections, diarrhea , failure to thrive , and malabsorption (of nutrients).

  Diagnosis

An immunodeficiency disease is suspected when children become ill frequently, especially from the same organisms. The profile of organisms that cause infection in patients with immunoglobulin deficiency syndrome is unique and is preliminary evidence for this disease. Laboratory tests are performed to verify the diagnosis. Antibodies can be found in the blood. Blood is collected and analyzed for the content and types of antibodies present. Depending on the type of immunoglobulin deficiency the laboratory tests will show a decrease or absence of antibodies or specific antibody subclasses.

  Treatment

Immunodeficiency diseases can not be cured. Patients are treated with antibiotics and immune serum. Immune serum is a source of antibodies. Antibiotics are useful for fighting bacteria infections. There are some drugs that are effective against fungi, but very few drugs that are effective against viral diseases.

Bone marrow transplantation can, in most cases, completely correct the immunodefiency.

  Prognosis

Patients with immunoglobulin defiency syndromes must practice impecable health maintenance and care, paying particular attention to optimal dental care, in order to stay in good health.

  Key Terms

•  Antibody

Another term for immunoglobulin. A protein molecule that specifically recognizes and attaches to infectious agents.

•  T-helper cell

A type of cell that recognizes foreign antigens and activates T- and B-cells in an immune response.

 

Some questions:

The arrow points to:

A. Albumin

B. a 1 globulin

C. a 2 globulin

D.b globulin

E. monoclonal protein

  A :

 

A 78-year-old black man, a retired chemistry professor, comes to you because of lumbosacral vertebral pain. There is no hepatomegaly. Cardiac exam is normal and there is no evidence of arthritis. His Hct, MCV, WBC and differential are normal. Liver enzymes are normal, but total serum protein is mildly elevated. The serum Ca is normal. You find no protein in his urine. A marrow aspirate&biopsy showed 6% plasma cells (normal=0-5%). A roetgenographic survey was negative. His serum protein electrophoresis is shown at right.

What is the most likely diagnosis based on the history and laboratory findings?

A. Waldenstrom's macroglobulinemia

B. Amyloidosis

C. Myeloma

D. Monoclonal Gammopathy of Unknown Significance

E. Heavy Chain Disease

 

 

 

 

A:Right , this is a monoclonal gammopathy of unknown significance (MGUS) in which there is no underlying cause, despite marrow plasmacytosis and an M protein. MGUS is seen in 5% of people >70yrs of age. Approximately 10% of MGUS patients develop myeloma within 5 years and almost 20% will develop a malignant PCD (myeloma,WM, amyloidosis, and ML) within 10 years.

Bone marrow biopsy and aspirate show a mild increase in plasma cells, but no mass lesion as would be seen in myeloma. The lack of significant lymphadenopathy, organomegaly, and renal disease argues against myeloma, Waldenstroms, heavy chain disease, and amyloidosis. Other studies might include immunoelectrophoresis and immunofixation electrophoresis.

 

A 72-year-old black woman, a retired school teacher, who you see for hypertension and mild arthritis, complains of mid-back and hip pain for 4-5 months. Two days ago she fractured her arm trying to lift her 15 month old grandson. Her Hct is 0.30; the WBC 3.8 x109/L with a normal differential. Serum Ca is elevated at > 12 mg/dL.Urine protein is 3+ positive. Her serum protein electrophoresis is shown at right. Physical examination shows no hepatosplenomegaly, nor lymphadenopathy.

What is the most likely primary diagnosis based on the history and laboratory findings?

A. Waldenstrom's macroglobulinemia

B. Amyloidosis

C. Myeloma

D. Monoclonal Gammopathy of Unknown Significance

E. Heavy Chain Disease

What additional studies are needed to confirm your differential diagnosis?

 

A: Right myeloma is more than twice a common in black individuals as in whites. The complaints of mid-back and hip pain and the pathologic fracture are typical of the bone lesions of myeloma. Her anemia and mildly decreased WBC suggest a process involving the marrow. The spillage of protein in the urine is seen in all but a small number of cases of myeloma and corresponds in amount to the mass of the lesion. Her serum protein electrophoresis shows the appearance of a monoclonal band in the g region. This requires further identification by immunoelectrophoresis.

The bone lesions typical of myeloma are not seen in Waldenstroms macroglobulinemia.

There is no lymphadenopathy as is common with heavy chain disease. While amlyoidosis might be part of myeloma, its presentation as primary disease unassociated with myeloma is generally more subtle than that described in this case and is without evidence of preceeding disease or bone lesions. Finally, this monoclonal gammopathy is clearly of clinical significance, not MGUS.

Other studies should include a bone survey, serum & urine protein electrophoresis, immunoelectrophoresis, immunofixation electrophoresis, and serum creatinine.</

For more on immunoelectrophoresis and immunofixation, return to the question and proceed to the next question

 

 

 

 

Immunosecretory Disorders: Myeloma

 

Immunoelectrophoresis (IEP)is important to confirm and define an apparent monoclonal band seen on SPEP.

Observe the shape of the IgG, IgA, & IgM precipitin arcs between the anti polyvalent Ig and the Control. Compare the arcs of the Pt with the Control looking for the presence of abnormal arcs and matching the abn arcs with those on the type specific heavy & light antisera.

Abn-Igs usually have skewed* or split arcs compared to normal (symmetrical due to Ig molecule heterogeneity). Usually abn-Igs are in excess and/or to the exclusion of normal. Here the Pt has an IgG in excess, but little IgA, or IgM. The k arc is in exess and matches the abn *arc seen against the anti polyvalent Ig. This is a k monoclonal IgG.

 

Immunoelectrophoresis (IEP) of a second case in which a monoclonal band was seen on SPEP.

Again compare the shape of the IgG, IgA, & IgM precipitin arcs between the anti polyvalent Ig and the Control.Look for abnormal arcs and match them with those on the type specific heavy & light antisera.

Here the abn-Ig has a split* arc compared to the Pts normal protein# (symmetrical due to Ig molecule heterogeneity). The *arc is identical to the l arc and the #arc with the k arc. The l arc is in exess and matches the abn *arc seen against the anti polyvalent Ig. This is a l monoclonal IgG.

This should be confirmed with immunofixation electrophoresis.

 

 

Immunosecretory Disorders

 

Immunofixation electrophoresis (M-fix) is useful for confirmation and specific identification of monoclonal bands. Antibodies against immunoglobulins, in this case IgG, k, and l, are used to identify the protein bands in the serum protein electrophoresis (SPEP) as an IgG l monoclonal band.

 

 

A 24-year-old woman, recently returned from graduate religious studies in India, comes to you because of soft tissue swelling of her lower extremities. She was treated with phenacetin for "arthritis" while in India. She also noted tenderness of both wrists and some numbness/sensation loss in her hands. On physical exam the soft tissue of her wrists is slightly swollen and firm. Laboratory studies show the Hct is 0.38 and the WBC 8.4x109/L with a normal differential. Her urine is 3+ positive for protein. There is no lymphadenopathy or hepatosplenomegaly. A skeletal survey is normal.

A. Waldenstrom's macroglobulinemia

B. Amlyoidosis

C. Myeloma

D. Monoclonal Gammopathy of Unknown Significance

E. Heavy Chain Disease

 

A; Primary amyloidosis is associated with plasma cell dyscrasias and idiopathic causes.

Amyloid infiltrates cause organ damage resulting in failure. In this case she developed a nephrotic syndrome. Analgesic nephritis resulting from papillary necrosis is secondary to the ingestion of large amounts of (2-3 kg of phenacetin in a 2-3 yr period). Heart failure can be seen secondary to amyloid deposition in the cardiac conduction system. Soft tissue accumulation leads to the carpal tunnel syndrome, as evidenced by the tenderness and soft tissue swelling of both wrists and some numbness/sensation loss in her hands.

A thorough GI exam is indicated as GI tract infiltration can cause macroglossia, hemorrhage, malabsorption, diarrhea, and obstruction. Rectal biopsy is a common means of obtaining tissue evidence of amyloidosis.

 

 

Immunosecretory Disorders

 

A 57 yr-old woman presents with headache & dizziness; numbness & blanching of her fingers. The IEP is at right. The PB smear shows 4+ rouleaux. You find enlarged axillary & inguinal lymph nodes & splenomegaly. X-rays show no lytic bone lesions.

In comparing the precipitin arcs of the Pt with the Control you see an abnormal arc in the Pt-antiPV and a matching arc on the IgM and k antisera.

The abn-Ig has a skewed or asymetrical arc and is in excess compared to normal. Here the Pt has an IgM in excess, but little IgG, or IgA. This is interpreted as a k monoclonal IgM, but should be confirmed with immunofixation as shown NEXT.

 

 

The immunofixation of this patient is shown at right. Does this confirm your interpretation of the IEP?

Based on the history and these results which of the following is the best diagnosis?

A. Waldenstrom's macroglobulinemia

B. Amlyoidosis

C. Myeloma

D. Monoclonal Gammopathy of Unknown Significance

E. Heavy Chain Disease

 

Yes, the immunofixation does confirm the IEP interpretation of a monoclonal lambda IgM gammopathy.

This together with the lymphadenopathy, splenomegaly and lack of lytic bone lesions is diagnostic of Waldenstroms macroglobulinemia.

The headache & dizziness are typical neurologic symptoms secondary to the hyperviscosity caused by the aggregation of the large IgM paraproteins. This also results in the numbness & blanching of her fingers known as Raynauds phenomenon. The enlarged axillary & inguina lymph nodes and splenomegaly and lack of lytic bone lesions is also consistent with Waldenstroms macroglobulinemia.

 

 

 

Multiple myeloma is generally characterized by all of the following EXCEPT:

A. Monoclonal gammopathy

B. Rouleaux formation

C. Anemia

D. Splenomegaly

E. Hypercalcemia

 

Common signs and (symptoms) of myeloma include anemia; lytic bone lesions (bone pain & pathologic fractures); hypercalcemia (mental status delta, renal calculi, bone pain & abdominal cramping); increased serum Ig [rouleaux, hyperviscosity syndrome, Raynauds phenomenon (severe intermittent pallor of digits), bleeding, confusion] and renal failure. Decreased production of normal Igs produces a high risk of bacterial infection (especially pneumococcal infection.

Splenomegaly and lymphadenopathy

 

 

In multiple myeloma the immunoglobulin most commonly elevated is:

A. IgA

B. IgG

C. IgM

D. IgD

E. IgE

 

In myeloma the abnormal immunoglobulin is most often IgG (50%) and sometimes IgA (25%), but rarely (<1%) IgM,IgD, or IgE.

 

Multiple myeloma is often associated with:

A. Decreased ESR (erythrocyte sedimentation rate)

B. Excretion of both kappa & lambda light chains in the urine

C. Osteoblastic skeletal lesions

D. Renal excretory impairment

E. Hyperalbuminemia

 

You would expect to see an increased ESR (erythrocyte sedimentation rate) due to the increased serum immunoglobulin.

The immunoglobulin is monoclonal and therefore urine spillage of protein would be monoclonal - kappa or lambda, but not both!

The bone lesions of myeloma are osteolytic.

Hypoglobulinemia is a feature of myeloma, not hyperalbuminemia.

Renal failure resulting in excretory impairment is caused by damage to the renal tubules from filtered light chains.

 

 

Which feature is more characteristic of Waldenstrom's macroglobulinemia than multiple myeloma?

A. Discrete lytic bone lesions

B. Bence-Jones protein in the urine

C. Rapid clinical course

D. Spleen and lymph node enlargement

E. IgA M-spike

 

Discrete lytic bone lesions and Bence-Jones proteins in the urine are features associated with myeloma, not Waldenstroms macroglobulinemia.

Waldenstroms is a slowly progressive disorder, with survival of 2-5 years and longer.

Splenomegaly and lymphadenopathy are features of HCD and Waldenstroms macroglobulinemia.

The malignant cells of Waldenstroms macroglobulinemia secrete a monoclonal IgM protein which causes a macroglobulinemia.

 

 

Hyperviscosity is a complication of which of the following diseases:

A. Waldenstrom's macroglobulinemia

B. Sickle cell anemia

C. IgA Myeloma

D. Polycythemia vera

E. All of the above

 

Hyperviscosity, caused by either increased cellular elements or increased serum protein levels, is a feature of all the diseases listed.

Hyperviscosity is seen with

·        Waldenstroms macroglobulinemia

·        and IgA myeloma because of the increased serum protein levels;

·         with polycythemia vera because of the increased numbers of RBCs,

·        and in sickle cell anemia because of the nondeformability of the sickled erythrocytes.

 

 

All of the following are complications associated with multiple myeloma EXCEPT:

A. Pathologic fractures

B. Increased susceptibility to infections

D. Hypergammaglobulinemia

E. Cryoglobulinemia

 RBC agglutination is the aggregation of RBCs into masses or clumps due to exposure to a specific erythrocyte antibody against RBCs. Examples are PNH (paroxysmal nocturnal hemoglobinuria) and cold hemagglutiation disease.

Pathologic fractures, increased susceptibility to infections, hypergammaglobulinemia, and cryoglobulinemia are all complications associated with myeloma.

 

Characteristic features of various heavy chain diseases include all of the following EXCEPT:

A. Increased levels of IgG kappa or lambda light chains

B. Association with AIHA, Sjogren's syndrome, SLE, etc.

C. Anemia, fever, lymphadenopathy, splenomegaly

D. abdominal mass; malabsorption; diarrhea

E. Mediterranean lymphoma

 

Heavy chain disease is characterized by increased amounts of a specific heavy chain -with no light chains.

Gamma HCD is associated with autoimmune diseases including AIHA, Sjogrens syndrome, rheumatoid arthritis, SLE, thyroiditis, etc.

alpha HCD is characterized by a GI lymphoma known as Mediterranean lymphoma and is associated with an abdominal mass; malabsorption; diarrhea.

Anemia, fever, lymphadenopathy, splenomegaly are common findings with the HCDs.

 

 

All of the following features of B cell gene rearrangements are true EXCEPT:

A. Two attempts at k rearrange ment must take place before an attempt at l rearrangement can take place

B. The Cm gene is physically closest to the JH region on chromosome 14

C. A heavy chain class switch allows identical VH/DH/JH antigen specificity to be expressed with different constant regions

D. Rearrangement translation transcription

E. The gene for k light chains is located on chromosome 2 and has a single constant region

 

Rearrangement preceeds transcription which preceeds translation.

The statements

A.) Two attempts at kappa rearrange ment must take place before an attempt at lambda rearrangement can take place, and

B.) The Cmu gene is physically closest to the JH region on chromosome 14, and

C.) A heavy chain class switch allows identical VH/DH/JH antigen specificity to be expressed with different constant regions, and

E.) The gene for kappa light chains is located on chromosome 2 and has a single constant region are all true.

 

All of the following are true EXCEPT:

A. Maternal IgG can cross the placenta

B. Waldenstrom's macroglobulinemia is associated with mature B lymphocytes that have not yet undergone a heavy chain class switch

C. IgA is a major immunoglobulin in GI tract and respiratory secretions

D. The Fab portion of IgG is important in the activation of complement

E. a2-macroglobulin is a protease inhibitor

 

The C region contains the Fc portion of the Ig molecule binding Ig to the cell and causes activation of complement.The other statements are true as written.

Enzyme

Glucose-6-phosphate dehydrogenase (G-6-PD) deficiency is the most common enzyme deficiency known to cause hemolysis. G-6-PD reduces NADP (nicotinamide-adenine-dinucleotide phosphate) to NADPH. NADPH reduces oxidized glutathione (GSSH) to its reduced form GSH. GSH prevents oxidation of RBC membranes and hemoglobin.

More than 200 million people, mainly Mediterranean, West African, Mid-East, and Southeast Asian populations, are estimated to be G-6-PD deficient.

The deficiency is sex-linked (M>F), but with varying degrees of deficiency - mild in blacks and severe in Mediterranean populations. Blacks often have an episodic variant in which oxidant compounds such as antimalarials, sulfonamides, or infections cause hemolysis. In Mediterranean populations G-6-PD deficiency may result in a chronic hemolysis. Women heterozygotes (half the normal amount of RBC) G6PD show increased resistance to P falciparum.

 

Stressors of the G6PD System

antimalarials

sulfonamides

nitrofurans

phenacetin

synthetic vitamin K

naphthalene (moth balls)

fava beans

infection

diabetic ketoacidosis

G6PD deficiency is usually asymptomatic.

During times of oxidant stress the PBS usually shows spherocytes, schistocytes, and "bite" cells and "blister" cells where denatured hemoglobin (Heinz bodies) were removed in the spleen.

G6PD enzyme assays reveal relatively high levels in reticulocytes and young erythrocytes, declining in older RBCs. In hemolysis it is the older cells which destroyed. Because of this hemolysis is usually self-limited.

Pyruvate kinase deficiency an autosomal recessive disorder causing polychromasia, anisocytosis, poikilocytosis with burr cells and acanthocytes, and NRBCs.

Reduced ATP formation causes RBC membrane rigidity, resulting in hemolysis. Symptoms are usually mild as increased 2,3-DPG causes a right shift of the 02-dissociation curve.

Persons homozygote for PK deficiency show severe anemia and are usually discovered in childhood. Splenomegaly, cholelithiasis and jaundice are frequent.

Methemoglobin is hemoglobin that has been oxidized from the ferrous (Fe++) to the ferric (Fe+++) state, thus unable to bind oxygen. The NADH- methemoglobin reductase enzyme reduces methemoglobin to hemoglobin. Methemoglobinemia results from either inadequate enzyme activity or too much methemoglobin production.

Hereditary autosomal recessive deficiency of NADH-methemoglobin reductase presents with cyanosis because methemoglobin cannot carry oxygen. The cyanosis is usually mild, but if severe can be treated with IV methylene blue, activating NADH- methemoglobin reductase.

Methemoglobin production may exceed the capacity of the normal NADH-

methemoglobin reductase pathway. This can be acquired due to drug or toxic oxidation of hemoglobin (analine dyes, anesthetics-benzocaine; prilocaine, naphthalene, nitrates, nitrites, nitroglycerin, paraquat, phenazopyridine, sulfamethoxazole, trimethadione, etc.).

Certain single amino acid substitutions within a hemoglobin globin chain can cause the iron to stabilize in the ferric state.

Related is the carboxyhemoglobin that results from carbon monoxide binding to hemoglobin. Hemoglobin binds CO more tightly than oxygen by a factor of 200. The tissues are deprived of oxygen.

 

Co poisoning produces massive amounts of carboxyhemoglobin causing a cherry pink discoloration of the brain.

 

 

An inherited M hemoglobin with the amino acid substitution in the b-globin chain would not cause cyanosis until approximately 6 months of age when beta chain production becomes dominant. Prior to 6 months gamma-globin chain production dominates.

If the amino acid substitution had been in the alpha chain, the cyanosis would have been present from birth.

Of the drug related immune hemolytic anemias which result in an intravascular hemolysis?

A. the hapten formation mechanism
B. the immune complex mechanism
C. the autoimmune mechanism
D. both the immune complex and autoimmune mechanisms
E. both the hapten and immune complex mechanisms

Only in the immune complex type does intravascular hemolysis occur.

In the immune complex type an IgM antibody forms against a drug. This IgM antibody causes formation of circulating immune complexes which activate complement. The complement then binds to RBCs and lyses them within the vascular space.


Heparin-Induced Thrombocytopenia

Heparin-induced thrombocytopenia, the most important thrombocytopenia resulting from drug-related antibodies, occurs in up to 5% of patients receiving bovine heparin and in 1% of those receiving porcine heparin. Rarely, patients with heparin-induced thrombocytopenia develop life-threatening arterial thromboses (eg, thromboembolic occlusion of limb arteries, strokes, acute MI).

The thrombocytopenia results from the binding of heparin-antibody complexes to Fc receptors on the platelet surface membrane.

 Platelet factor 4, a cationic and strongly heparin-binding protein secreted from platelet alpha granules, may localize heparin on platelet and endothelial cell surfaces.

In addition, platelet factor 4-heparin complexes are the principal antigens.

 Platelet clumps can form, causing vessel obstruction.

Heparin should be stopped in any patient who becomes thrombocytopenic. Because clinical trials have demonstrated that 5 days of heparin therapy are sufficient to treat venous thrombosis and because most patients begin oral anticoagulants simultaneously with heparin, heparin can usually be stopped safely. Laboratory assays do not aid these clinical decisions.

A 53-year-old woman presented to the emergency department with petechiae and purpura of the lower legs and blood blisters on the oral mucosa. She reported that her physician had placed her on quinidine for leg cramps about three weeks earlier.

The complete blood count was normal except for a platelet count of 5,000/mm3 (normal, 150,000 to 450,000/mm3). A diagnosis of quinidine-induced thrombocytopenia was made on clinical grounds.

The broad group of drug-induced thrombocytopenias can be readily divided into immunologic and nonimmunologic. This patient's thrombocytopenia is immunologic; indeed, quinidine is a common cause of drug-induced immune thrombocytopenia.

Nonimmune thrombocytopenia is the most common cause of drug-induced thrombocytopenia in hospitalized patients and is typically seen on cancer wards, particularly among leukemia patients. It is invariably associated with bone marrow suppression and characteristically originates as a dose-dependent and quite predictable side effect of treatment with chemotherapeutic agents. Depending on the agent used, the platelet count can fall to very low levels. These patients are usually treated with platelet transfusion. Since none of these episodes is unexpected, with proper treatment the thrombocytopenia is seldom lethal.

Immune thrombocytopenia, as illustrated by this case, can be defined as unexpected--also known as idiosyncratic--thrombocytopenia associated with the administration of a drug. Thrombocytopenia usually begins within days or weeks after drug therapy is started. Occasionally, it happens after long exposure; the thrombocytopenia develops rapidly, and often is so severe that the patient seeks medical attention. Given sufficiently sensitive assays, immune mechanisms for the thrombocytopenia usually can be demonstrated. Typically, the platelet destruction is IgG-mediated; occasionally, it can be mediated by IgM or complement.

A number of drugs seem to have a strong association with immune thrombocytopenia. Although quinine and quinidine cause many such cases, the risk per dose is extremely low, given the fact that quinine is present in tonic water; if quinine were a common allergen, we would see literally tens of thousands of patients with this problem every year.

Other drugs that can cause immune thrombocytopenia include a number of antibiotics, especially the sulfonamides (combination sulfonamides such as trimethoprim-sulfamethoxazole are frequently implicated); the H2 antagonists such as cimetidine; and various other agents, including furosemide. It is important to note that virtually every drug, including commonly used drugs such as acetamin-ophen, have been associated with immune thrombocytopenia.


Case 1 Treatment


Quinidine was withdrawn. The patient was given high-dose IV IgG, 1 g/kg over six to eight hours, repeated on the next day. The platelet count returned to normal over the next four days.

There is a hierarchy with regard to intervention in drug-induced immune thrombocytopenia: Intervention is least urgent in patients with no symptoms; it is more urgent in those with petechiae, and most urgent in patients with petechiae plus "wet" purpura.

In asymptomatic patients with drug-induced immune thrombocytopenia, the drug should be withdrawn and a structurally different drug should be substituted if the patient's condition requires treatment. For example, in a patient whose thrombocytopenia developed in response to a sulfonamide, therapy might be switched to a cephalosporin, depending on the sensitivity of the infecting organism.

Petechiae in drug-induced thrombocytopenia typically occur on the dependent regions of the body. These patients require intervention.

So-called wet purpura is defined as blood blisters inside the mouth, typically at the bite margins. Patients will describe purple bumps that they can feel with their tongue. Some of those can be the size of a grape; others are smaller. These patients are at risk for major and possibly life-threatening hemorrhage. For that reason, this is the one group of patients who should be admitted to the hospital and given urgent treatment. Complete recovery can be expected provided that the drug is stopped and patients are supported until the thrombocytopenia resolves.

While I rely heavily on symptoms (or lack thereof) to guide the treatment of drug-induced thrombocytopenia, management decisions can also be based on platelet counts. Clinical signs correlate well with the platelet count, so that the end result is usually the same.

Most patients with platelet counts that exceed 20,000/ mm3 are asymptomatic, unless they have taken an antiplatelet agent such as aspirin or alcohol. I have also seen asymptomatic patients with platelet counts as low as 15,000/mm3; such patients apparently have highly functional platelets. Even with counts that low, I will frequently treat only by stopping the drug if the patient is asymptomatic.

Petechiae and purpura are often seen with platelet counts of 10,000 to 20,000/mm3. I usually treat those cases, although there is some latitude in that regard. A platelet count of under 10,000/mm3 means the patient must have intervention. In my experience, platelet counts of 1,000 to 2,000/mm3 are invariably accompanied by major wet purpura. These patients are at great risk for hemorrhage.

The treatment for all patients is the same. First, the drug is stopped. The next step is to consider blockade of the reticuloendothelial system, using high-dose intravenous IgG at a dose of 1 g/kg, over six to eight hours, repeated on the next day. Alternatively, intravenous Rho(D) immune globulin can be given, provided that the patient is Rh-positive. The typical adult dose is 2 to 2.5 mg administered over 30 minutes. Both IV IgG and anti-Rh-D usually raise the platelet count within a few days. The advantages of anti-Rh-D over high-dose IV IgG are that the former is easier to administer, and patients sometimes tolerate it better; for example, it does not cause headaches, as IV IgG often does.

Anti-Rh-D is an antibody against the Rh group on red blood cells--the agent is used to prevent Rh sensitization in Rh-negative mothers with an Rh-positive fetus. An intramuscular preparation is customarily used in those patients; for thrombocytopenia, we use anti-Rh-D that has been modified so that it can be administered intravenously.

The strategy for the use of anti-Rh-D in thrombocytopenia is to give it in a dose high enough that the D sites on red cells are sensitized by the antibody, but not at such a high dose that the cells are completely covered with the antibody. The phagocytic cells that have been destroying platelets then go after the red blood cells because there are so many more of them compared with the platelets. This sets up a so-called reticuloendothelial competitive state, or blockade.

Rarely, we encounter patients who have such severe drug-induced thrombocytopenia that we consider them to have a major risk of fatal hemorrhage. We will tranfuse those patients with random-donor platelets. Although the transfused platelets will not have a normal survival time, they may attract enough of the offending drug to allow the patient's own platelet count to rise.

If a laboratory is sufficiently sophisticated, it is often possible to demonstrate which drug caused the thrombocytopenia, using a sensitive diagnostic test to measure drug-dependent binding of antibody to platelets. That test is performed only in a few centers in the United States and Canada, but it does have the benefit of providing a definitive diagnosis.

Once patients have experienced an episode of drug-induced thrombocytopenia, they should never take that drug again, since the thrombocytopenia tends to recur with every subsequent exposure. I recommend that these patients wear a medical alert bracelet to indicate their allergy.


Case 2 Presentation


A 55-year-old woman presented with petechiae and purpura. Her platelet count was less than 10,000/mm3. The woman had long-standing rheumatoid arthritis. She had been treated with a number of anti-arthritic drugs, with limited success. Five months earlier, she had been started on gold injections.

Gold injections were immediately discontinued. Treatment with high-dose IV IgG raised the platelet count to safe levels, but within two weeks the count began to fall again. She was then given prednisone, 30 mg every other day. After two months, the platelet count had risen to normal levels, and tapering of the prednisone was begun. As the corticosteroid was tapered, however, the platelet count fell again. Three months after the onset of thrombocytopenia, she underwent splenectomy. Afterwards, the platelet count returned to normal levels. Genetic testing showed that the patient's HLA haplotype is B8/DR3.

Gold-induced thrombocytopenia may be the only drug-induced immune thrombocytopenia in which a true and persisting autoantibody develops. There is some debate about this, however, because when gold is used as an injectable therapy for rheumatoid arthritis, it can have an extremely long half-life. Therefore, it is possible that gold leaches from the bones and into the circulation, where it causes persistent thrombocytopenia. Nevertheless, serologic tests in patients with gold-induced thrombocytopenia strongly suggest that these patients have a true autoimmune disorder.

Another interesting aspect of gold-induced thrombocytopenia is that there appears to be a genetic predisposition to the syndrome. Up to 80% of patients carry a specific HLA DR haplotype, B8/DR3. Although B8 and DR3 are closely linked, it is likely that the DR3 alloantigen is the one responsible for the immunogenicity of gold. Why the immune reaction occurs remains unknown.

Initial management of gold-induced thrombocytopenia is the same as with any other drug-induced immune thrombocytopenia: Stop the drug and provide supportive treatment if the fall in platelet count is sufficiently severe. For example, if the patient has petechiae and purpura and a very low platelet count, most physicians would use high-dose IV IgG.

Unlike patients with other drug-induced thrombocytopenias, however, many of those with gold-induced thrombocytopenia will have a relapse after the IV IgG wears off, which typically occurs in two to four weeks. When that happens, either additional IgG can be given or corticosteroids can be used.

Repeat doses of IgG have limited usefulness. In the average adult, a full treatment with high-dose IgG provides 180 g, which typically doubles the serum IgG concentration. If treatments are given too frequently, that protein load can cause hyperviscosity and heart failure. Equally important, the use of IV IgG in immune thrombocytopenia is associated with a fairly dramatic tachyphylaxis. The initial treatment provides a major boost in the platelet count, the next treatment a smaller one; with each successive treatment, the effectiveness gradually becomes modest. If treatments are withheld for a time, however, the patient will respond to IgG again.

If I have used corticosteroids and the patient continues to have thrombocytopenia after the steroids are tapered, I would move to a splenectomy in these patients. As with idiopathic thrombocytopenia, splenectomy is effective in 60% to 75% of cases.

If the patient does not respond to splenectomy, the physician would be obligated to try other treatments that are used in immune thrombocytopenia, many of which are difficult to administer and may not always be successful. There are also anecdotal reports suggesting that the removal of gold with chelating agents such as desferoxamine can shorten the thrombocytopenia, but that would not be typical therapy.


Case 3 Presentation


A 52-year-old man underwent coronary artery bypass surgery. During surgery, he was treated with full-dose heparin, 30,000 units. Over the next week, he was treated with 5,000 units twice a day.

On day 7 of the patient's hospitalization, a platelet count of 60,000/mm3 was noted, and his right leg became cold and pale. Heparin-induced thrombocytopenia was suspected. Heparin was discontinued. A thrombus was removed by Fogarty catheter from the right superficial femoral artery. Despite the embolectomy, the patient's leg was irreversibly ischemic. He subsequently required a below-knee amputation.

Heparin-induced thrombocytopenia is by far the most common and most important drug-induced immune thrombocytopenic disorder that physicians face today. It is important for a number of reasons. First, heparin use is virtually ubiquitous in the hospital. In fact, the use of heparin is increasing, since the indications for it have been expanded to include arterial as well as venous thrombotic conditions.

Second, unlike other thrombocytopenic disorders of this type, heparin-induced thrombocytopenia is associated with only a moderate decrease in platelets: Counts typically range from a low of about 50,000/mm3 to a high of about 100,000/mm3. Because of that, cases may go unsuspected and undiagnosed.

Third, heparin-induced thrombocytopenia is the one drug-induced thrombocytopenia that is associated not only with bleeding but also with thrombotic complications. Indeed, the thrombotic complications cause virtually all of the morbidity and mortality in this syndrome.

Finally, there is the issue of litigation. The legal concept of res ipsa loquitur (the thing speaks for itself) is central to these cases, which often involve multimillion-dollar claims for damages: Juries see a plaintiff who entered the hospital with healthy limbs and left an amputee, and it seems self-evident to them that someone must be at fault. Unfortunately, this catastrophic reaction to heparin is unpredictable and often unpreventable.

We have known about heparin-induced thrombocytopenia for more than 30 years, but only in the past five years have we had a thorough understanding of its pathophysiology and its diagnosis. Even more recently have we gained some insight into the treatment of this disorder, although there is still debate on that subject.

Heparin-induced thrombocytopenia is defined as a fall in the platelet count of at least 50%, accompanied by a positive serologic test for the responsible antibody. Onset typically occurs five or more days after the initiation of heparin therapy, with peak onset around seven to 10 days. Rarely, thrombocytopenia begins after two weeks; occasionally (especially if the patient has received heparin in the previous month or two), it can occur as early as first or second day after heparin exposure.

In most patients, the platelet count fall is so mild that they remain asymptomatic. Bleeding is rare. When thrombosis occurs, however--which may not be until several weeks later, perhaps after the discontinuation of heparin--the patient becomes immediately symptomatic. It is then that the diagnosis is often made.

Studies of heparin-induced thrombocytopenia have documented that the incidence is related to several factors. One is the type of heparin used. Bovine heparin carries the greatest risk, possibly as high as 10%; porcine heparin carries a risk of 2% to 4%.

The incidence of heparin-induced thrombocytopenia is also dose-dependent. The frequency is highest in patients who receive full-dose heparin, which is defined as 20,000 to 40,000 units per day. It is lower with low or intermediate doses, defined as 5,000 units two or three times a day; and it is far lower for very-low-dose heparin, which is the amount used to maintain the patency of arterial catheters. The new low-molecular-weight heparins also carry very little risk of heparin-induced thrombocytopenia--probably under 1%. Nevertheless, heparin-induced thrombocytopenia has been identified for every single heparin preparation currently used, by any route and at any dose.

Finally, for unknown reasons, the risk of thrombocytopenia and thrombosis is related to the clinical situation. The risk is lowest on general medical units; quite high on orthopedic surgery units; and highest in patients undergoing cardiopulmonary bypass surgery.

The risk of the thrombocytopenia has been well defined in a number of prospective studies. The risk of thrombotic complications is only now being studied; they appear to be related to the clinical situation itself. In certain patient populations, heparin-induced thrombocytopenia occurs without the clotting complications, whereas in others, both occur. Several recent studies have shown that venous clotting complications outnumber arterial thrombi by three to one. The venous complications consist of deep-vein thrombosis and pulmonary embolism; the arterial complications include peripheral arterial thrombosis and thrombosis of the heart or brain. In addition, skin necrosis is increasingly described as a complication of heparin-induced thrombocytopenia.

Heparin-Induced Thrombocytopenia: Pathophysiology

In the past few years, scientists have identified the target antigen in heparin-induced thrombocytopenia as a complex of heparin and a small platelet alpha-granular component called platelet factor 4 (PF-4). Each heparin molecule bundles two or four PF-4 molecules together, and this complex then binds to the platelet membrane, through a process that remains uncertain. It appears that heparin itself is not immunogenic; rather, the immunogenicity arises from the conformational change in the PF-4 caused by heparin (Figure 1). Patients at risk form an antibody--typically IgG--to the heparin/PF-4 complex. Fortunately, thrombocytopenia develops in only a small proportion of the patients who form such antibodies.

The antibody binds to the heparin/PF-4 complex through its Fab region; its Fc region then binds to the platelet by occupying the platelet Fc receptor, which is of the FCR gamma-2 family (there are approximately 1,000 to 2,000 of these receptors on each platelet). Once this receptor has been occupied, the platelet becomes intensively reactive and will release platelet-derived microparticles into the circulation.

The platelet-derived microparticles, which are procoagulant, appear to be the stimulus responsible for thrombus formation. They pass through the circulation and probably home in on sites of vessel damage, where they activate the coagulation cascade. It is likely that endothelial cells are also the target of the IgG and heparin/PF-4 immune complexes.

Heparin-Induced Thrombocytopenia: Diagnosis

The diagnosis is made on clinical grounds. Physicians should be particularly alert to the possibility of heparin-induced thrombocytopenia when the platelet count falls after five to 10 days of heparin therapy.

The diagnosis can be confirmed in either of two ways. Probably the most sensitive and specific test is the serotonin release assay. This measures platelet activation as indicated by serotonin release from normal platelets in the presence of the patient's serum plus heparin at two concentrations. The assay takes several days to complete, so it is not useful for immediate patient management. The other technique is a recently described ELISA assay that measures the binding of patient IgG to a complex of heparin and PF-4 on microtiter wells. There is some debate as to which test is better. Although there is good agreement of results with the two tests, each may detect the disorder in a few cases that are missed by the other method.

Heparin-Induced Thrombocytopenia: Treatment

The treatment of heparin-induced thrombocytopenia is complex and multipronged. First, one should try to stop the heparin as soon as possible--although that does not necessarily mean that it is stopped the minute the diagnosis is made.

Second, if the patient has had an arterial or venous thrombus, it is appropriate to provide supportive treatment. For example, a patient who has had a myocardial infarction (MI) should be treated according to an MI protocol. For large arterial thrombi, treatment might include physically removing the thrombus from the occluded artery, or using fibrinolytic agents to try to dissolve clots.

The biggest problem is that we now know that the disorder itself can be a prothrombotic state, so we need to try to control ongoing thrombosis. One treatment that should not be used in acute heparin-induced thrombocytopenia is warfarin. The reason is that while warfarin reduces circulating concentrations of vitamin K-dependent clotting factors II, VII, IX, and X, it also reduces those of protein C and protein S, which are natural anticoagulants. Because protein C has a short half-life, it is reduced faster than the prothrombotic proteins, which means that clotting will worsen in some patients.

Unfortunately, heparin-induced thrombocytopenia develops in some patients when treatment is changed from heparin to warfarin in preparation for longer-term anticoagulation, and the diagnosis is not made until after they have already begun to receive warfarin. If they are stable (more than three days) on warfarin, I would continue the drug. Otherwise, I would adminster fresh-frozen plasma to restore protein C levels and provide natural anticoagulation, in addition to providing the standard anticoagulant treatments used for heparin-induced thrombocytopenia.

Three specific anticoagulant treatments are now being tested in Canada and the United States. As of this writing, none has been approved by the U. S. Food and Drug Administration. One is called orgaran (ORG 10172) or danaparoid. Formulations of this heparinlike molecule contain a tiny amount of heparin contaminant, and about 10% of patients with heparin-induced thrombocytopenia will cross-react with it. That possibility should be investigated in vitro before starting a patient on the drug.

The second treatment category comprises thrombin-specific inhibitors. These include argatroban and hirudin or hirudin analogs. In theory, thrombin-specific inhibitors may be the ideal agents for this disorder.

Ancrod, a drug that has been used in Canada for some time, is a snake venom extract that depletes fibrinogen and so prevents clotting. The drug has the advantage of lowering plasma viscosity because it reduces fibrinogen levels. It has the theoretical disadvantage of not controlling thrombin; if a patient has any laboratory evidence of disseminated intravascular coagulation, ancrod should not be used.

In addition to those primary treatments, there are a number of supportive treatments that have anecdotal descriptions of efficacy. These include high-dose IgG to try to disrupt the immune complex on the platelet; plasma exchange, which we have used in a number of our patients to try to remove the procoagulant substance; and anticoagulants and antiplatelet drugs, most of which seem to be second-line therapies when compared with the other treatments.

Finally, as with other drug-induced thrombocytopenias, no patient with heparin-induced thrombocytopenia should ever again be exposed to heparin, and I recommend that these patients wear a medical alert bracelet.


Case Commentary


PETER A. CASSILETH
University
of Miami

I believe that it is worthwhile to expand on some of the points Kelton makes in his overview of drug-induced thrombocytopenia--namely, the indications for treatment of thrombocytopenia, the medicolegal challenges of heparin therapy in a litigious era, and the role of low-molecular-weight heparin in current therapy.

In general, the risk of bleeding from thrombocytopenia does correlate roughly with clinical signs. Because of the increased venous pressure in the lower extremities caused by dependency--and the resulting challenge to platelet competency--petechiae on the legs are the earliest manifestation of thrombocytopenia. Purpura from minimal trauma occurs next. Once hemorrhage occurs on moist internal membranes such as the mouth or conjunctiva, the risk of serious hemorrhage increases. The presence of those findings, regardless of the severity of the thrombocytopenia, warrants therapy. Kelton indicates that even without the development of "wet" purpura, he tends to intervene when platelet counts are in the range of 10,000 to 20,000/mm3. This is in contrast to current guidelines for treatment of thrombocytopenia resulting from cancer chemo- therapy, which suggest that intervention in the absence of clinical hemorrhagic findings is necessary only when the platelet count is less than 10,000/mm3. The difference in perceived risk may relate to the antigen/antibody coating on platelets interfering with platelet function and adding to hemostatic impairment. When evaluating the bleeding risk in a patient with thrombocytopenia, one must also consider whether the platelet count is continuing to fall, is stable, or is rising; the potential for rapid recovery; and the length of time in which stable thrombocytopenia (at any level) has been present without producing signs or symptoms.

The fact that heparin so frequently causes mild thrombocytopenia and yet is rarely associated with serious arterial or venous thrombosis carries a risk for tort actions against the treating physician if major adverse events ensue. That risk raises the question of what management guidelines should be. For example, should all patients on heparin routinely have platelet count determinations? If so, how often should they be done, and for how long? Kelton notes that although the development of heparin-induced thrombocytopenia usually occurs seven to 10 days after the start of therapy, it can occur as early as the first day (in previously treated patients) or as late as two to three weeks later. If platelet counts fall at all, should heparin be discontinued? Most hematologists would be concerned about a decrease in platelet count below 100,000/mm3 and would then discontinue heparin. Nevertheless, heparin-induced major vascular occlusion has occurred when platelet counts were greater than 100,000/mm3. A major fall in the platelet count--for example, to half of the pretreatment level--would be a matter of some concern, but what should be done if the count falls modestly from a preheparin level of 200,000/mm3 to 145,000/mm3? How can one be sure that an observed minor fall in the count will not become, perhaps two days later, a major decrease in platelets associated with thrombosis?

We do not have clear-cut answers to those questions; I do not believe that firm guidelines have been drawn, either from a medical or a medicolegal perspective. I do believe that prudence dictates that patients on heparin therapy should have a baseline platelet count for subsequent comparison and that platelet counts should be repeated periodically, although the optimal intervals for repeat determinations and the appropriate response to moderate decreases in platelet levels remain unclear.

The potential for heparin-induced thrombocytopenia argues for starting warfarin concomitantly with heparin, when practical, so that oral anticoagulation can be established sooner. Usually that will permit the heparin to be withdrawn early, prior to the time when most heparin-induced thrombocytopenia becomes manifest.

Low-molecular-weight heparin has a number of advantages. Unlike standard heparin, it can be given in fixed doses; in addition, administration is easier, frequent monitoring of anticoagulant effects is unnecessary, and the incidence of drug-induced thrombocytopenia is substantially lower. Moreover, randomized studies are providing increasing evidence that low-molecular-weight heparin works just as well as standard heparin in both prophylaxis and treatment of phlebothrombotic disease. The increased cost of low-molecular-weight heparin needs to be balanced against the decreased expenses associated with administration, obviation of anticoagulant monitoring, and decreased risk of managing the potentially catastrophic complications of heparin-induced thrombocytopenia. There is much to recommend low-molecular-weight heparin as the preferred formulation for phlebothrombotic disease.


Human Diseases Associated with Immune Complexes



DIFFUSE CONNECTIVE TISSUE DISEASES (CTDs)

Autoimmune Diseases:

    • Systemic Lupus Erythematosus (SLE)
    • Rheumatoid Arthritis (RA)
    • Sjogren's Syndrome (SS)
    • Progressive Systemic Sclerosis (PSS)
    • Mixed Connective Tissue Disease (MCTD)

Other:

    • Polyarteritis Nodosa (PAN)

GLOMERULONEPHRITIS (GN)

    • Exogenous antigens ( bacterial, viral, parasitic)
    • Autologous antigens (nuclear, IgG, thyroglobulin, tumor)

INFECTIOUS DISEASES

    • Bacterial: infective endocarditis, disseminated streptococcal, staphylococcal, meningococcal, gonococcal infections, Lyme disease (borreliosis), syphilis, leprosy
    • Viral: hepatitis B, cytomegalovirus infection, infectious mononucleosis
    • Parasitic: malaria, toxoplasmosis, trypanosomiasis

Revised Criteria for the Classification of Systemic Lupus Erythematosus


Criterion:

Definition:

1. Malar rash

Fixed erythema, flat or raised, over the malar eminences, tending to spare the nasolabial folds

2. Discoid rash

Erythematous raised patches with adherent keratotic scaling and follicular plugging; atrophic scarring may occur in older lesions

3. Photosensitivity

Skin rash as a result of unusual reaction to sunlight, by patient history or physician observation

4. Oral ulcers

Oral or nasopharyngeal ulceration, usually painless, observed by a physician

5. Arthritis

Nonerosive arthritis involving two or more peripheral joints, characterized by tenderness, swelling, or effusion

6. Serositis

  1. Pleuritis - convincing history or pleuritic pain or rub heard by a physician or evidence of pleural effusion, or
  2. Pericarditis - documented by ECG or rub or evidence of pericardial effusion

7. Renal disorder

  1. Persistent proteinuria greater than 0.5 grams per day or greater than 3+ if quantitation not performed, or
  2. Cellular casts - may be red cell, hemoglobin, granular, tubular, or mixed

8. Neurologic disorder

  1. Seizures - in the absence of offending drugs or known metabolic derangements, e.g., uremia, ketoacidosis, or electrolyte imbalance, or
  2. Psychosis - in the absence of offending drugs or known metabolic derangements, e.g., uremia, ketoacidosis, or electrolyte imbalance

9. Hematologic disorder

  1. Hemolytic anemia - with reticulocytosis, or
  2. Leukopenia - less than 4,000/mm^3 (4.0x10^9/L) on two or more occasions, or
  3. Lymphopenia - less than 1,500/mm^3 (1.5x10^9/L) on two or more occasions, or
  4. Thrombocytopenia - less than 100,000/mm^3 (100x10^9/L) in the absence of offending drugs

10. Immunologic disorder

  1. Positive LE cell preparation, or
  2. Anti-DNA: antibody to native DNA in abnormal titer, or
  3. Anti-Sm: presence of antibody to Sm nuclear antigen, or
  4. False positive serologic test for syphilis known to be positive for at least 6 months and confirmed by Treponema pallidum immobilization or fluorescent treponemal antibody absorption test

11. Antinuclear antibody

An abnormal titer of antinuclear antibody by immunofluorescence or an equivalent assay at any point in time and in the absence of drugs known to be associated with "drug-induced lupus" syndrome


Connective Tissue Diseases Associated with Antinuclear Antibodies

 

Some Diseases (Other than CTDs) Associated with Antinuclear Antibodies


Other Autoimmune Diseases

  • Hashimoto's thyroiditis
  • Myasthenia gravis

Infectious diseases

  • Tuberculosis
  • Histoplasmosis
  • Infectious mononucleosis
  • Chronic active hepatitis

Miscellaneous

  • Pernicious anemia
  • Ulcerative colitis
  • Alcoholic cirrhosis of the liver
  • Lymphoproliferative disorders

ANA Fluorescence Patterns and CTD Association

Nuclear Fluorescence Pattern

Disease Association

Nature of Reactive Antigen




Rim (peripheral)

SLE

dsDNA

Homogeneous (diffuse)

Drug-induced LE, SLE

Histones, deoxyribonucleopr.

Speckled

SLE, Sjogren's, MCTD, scleroderma

Nonhistone proteins, nuclear RNPs, etc.

Nucleolar

Scleroderma

Nucleolar RNPs


Special Antibody Assays in the Connective Tissue Diseases


anti-ds DNA

SLE

anti-La

Sjogren's, SLE

anti-Sm

SLE

anti-Scl 70

Scleroderma

anti-histone

Drug induced LE, SLE

anti-nucleolar

Scleroderma

anti-U1 RNP

MCTD, SLE

anti-centromere

CREST*

anti-Ro

SLE, Sjogren's

anti-Jo-1

Polymyositis


*Acronym for syndrome of scleroderma with calcinosis (C), Raynaud's phenomenon (paroxysmal blanching and numbness of fingers) (R), esophageal dysmotility (E), sclerodactyly (S), and telangiectasia (T).