MLAB 1315- Hematology Fall 2007 Keri Brophy-Martinez Unit 24: MULTIPLE MYELOMA AND RELATED PLASMA CELL DISORDERS

Multiple myeloma This is a disorder in which there is overproduction of abnormal plasma cells which are the final stage in the development of B lymphocytes.

Multiple myeloma Etiology 5 cases per 100,000 persons per year 50% greater risk for men than women Risk increases with age; rare under 40 Suspected cause is chronic stimulation of the immune system from environmental sources.

Multiple myeloma Characteristics Expanding plasma cell mass in bone marrow causes pancytopenia and destruction of the bone cortex. This is painful because nerves get stretched. Increased production of immunoglobulin heavy and light chains (monoclonal gammopathy) Heavy chains: IgG, IgA, IgD, IgE, IgM Light chains: kappa, lambda Most common type of multiple myeloma is increased production of IgG. Hyperviscosity syndrome Excess immunoglobulin causes viscous blood which sludges and causes fluid congestion. Bence-Jones protein Light chains spill into the urine and can be detected by lab test. Causes kidney damage

Multiple myeloma Laboratory tests Protein electrophoresis - separates the proteins in the serum Immunoelectrophoresis - identifies the heavy and light chains Quantitative immunoglobulins - quantitative measurement of the immunoglobulin chains CBC and peripheral smear Red cells form characteristic rouleaux formation (resemble stacked coins) Plasma cells may be seen in advanced cases The presence of significant numbers of plasma cells on peripheral blood smear constitutes plasma cell leukemia

Multiple myeloma: Lab tests con’t ESR Increased - serum protein causes red cells to stick together and fall faster Bone marrow Increased number of plasma cells which form “sheets” Chemistry studies Increased BUN and creatinine (kidney tests) Increased calcium Increased LDH

Multiple myeloma Treatment Chemotherapy Radiation for localized areas Bone marrow transplant for younger patients

Waldenström’s macroglobulinemia Overproduction of monoclonal IgM

Waldenström’s macroglobulinemia Clinical features Usually presents when patients are in their 70's. Hyperviscosity syndrome is common. Blurred vision IgM interferes with platelet function and bleeding problems occur. Characteristic bruising is called cryoglobulinemic purpura Cryoglobulins precipitate on exposure to cold

Waldenström’s macroglobulinemia Therapy Chemotherapy Plasmapheresis