Commentary on “Clinicopathological Correlates of IgM Paraproteinemias” What is Waldenström's Macroglobulinemia?

Human monoclonal macroglobulins with antibody activity

Assays for specific antigen-binding activity were performed on sera from 172 patients with monoclonal macroglobulinemia defined by immunofixation electrophoresis. The sera were collected between 1970 and 2002. Mean IgM level was 1,409 mg/dL with a range from 70 to 6,800. Cryoglobulins were identified in 15.3% (26/170 sera: 12 trace, five single component, and nine mixed IgM-IgG). Rheumatoid factor (RF) was detected in 19 of 151 (12.6%) samples with titers ranging from 1:80 to 1:327,680. Among the nine mixed IgM-IgG cryos, eight were RF-positive and six of six displayed positivity for hepatitis C virus. Cold agglutinins (CA) were present in 8.5% (10/117) of sera with anti-I titers between 1:512 and 1:65,536. IgM binding to a series of glycosaminoglycan oligosaccharides, glycolipids, and glycoprotein antigens was found in 75 samples (43%). IgM binding to antigens having known associations to polyneuropathies occurred in 20 patients (12%). Antinuclear antibody (ANA) was documented in 10.7% (18/169) of sera. Anti-DNA activity was absent in all samples tested. Sera from 71% of patients with monoclonal macroglobulinemia in this series exhibited binding to autoantigens. Some of these immune complexes resulted in clinically significant manifestations. Our results suggest that many monoclonal immunoglobulins may be functional antibodies rather than "paraproteins." Characterization of antigen-binding activities may provide insight into the pathogenesis of monoclonal gammopathies.

Myeloma and macroglobulinemia: what are the criteria for diagnosis?

Monoclonal gammopathy of undetermined significance (MGUS) is much more common than either multiple myeloma or Waldenström's macroglobulinemia. Since individuals with MGUS do not need treatment but only monitoring, it is important to distinguish this group from those with progressive plasma cell disorders. Criteria for diagnosis of myeloma and macroglobulinemia and laboratory pitfalls related to meeting these criteria are discussed. The importance of using the serum protein electrophoretic pattern in determining the magnitude of the monoclonal immunoglobulin component and the need for accurate quantification and characterization of urine protein are emphasized. Uniform definitions and consensus on diagnostic standards are becoming increasingly necessary if more effective and less toxic therapeutic approaches for patients with myeloma and macroglobulinemia are to be applied in an optimal manner.

Monoclonal antibodies in the prehybridoma era: a brief historical perspective and personal reminiscence

Emil von Behring, an immunologist, received the first Nobel Prize in Physiology or Medicine in 1901 for his studies on serum therapy of diphtheria. Seventeen Nobel Prizes have been awarded to scientists for their work in immunology and related disciplines. E. Metchnikoff and P. Ehrlich were pioneers who became associated with cellular and humoral theories of immunity, respectively. Almroth Wright described opsonins and was a vigorous advocate of vaccine therapy for bacterial diseases. He was an influential scientist and mentor who served as the model for Bernard Shaw's play, The Doctor's Dilemma. Immunochemistry developed through the work of K. Landsteiner, M. Heidelberger, E. Kabat, and many others. At mid-20th century, cell-selection theories of antibody formation championed by N. Jerne and F.M. Burnet shifted the field from a chemical to a biological orientation. Myeloma immunoglobulins, Bence Jones proteins, and monoclonal macroglobulins from patients and mice played a central role in elucidation of normal immunoglobulin structure, genetics, synthesis, and metabolism. By the late 1960s, antibody activity in some human myeloma and Waldenström macroglobulin paraproteins had been documented. Subsequently, other human paraproteins were shown to have antigen-binding properties, principally to auto- or bacterial antigens. The development of hybridoma technology by G. Köhler and C. Milstein revolutionized immunology after 1975. These investigators demonstrated that antibody-producing cells of virtually any desired specificity could be fused with a myeloma cell line, the result being unlimited amounts of homogeneous (monoclonal) antibodies carrying that specificity. Monoclonal antibodies have been shown to have efficacy in cancer therapy, particularly in patients with lymphoma and breast cancer. It is likely that this approach, alone and in combination with other modalities, will prove useful for patients with additional types of malignancies.