Anti-Human Immunoglobulin G Activity of Membrane-Bound Monoclonal Immunoglobulin M in Lymphoproliferative Disorders

Abstract

Lymphocytes from a patient with Waldenstrom's macroglobulinemia and known anti-immunoglobulin IgG activity of serum monoclonal IgM and lymphocytes from selected patients with chronic lymphocytic leukemia were studied by the membrane immunofluorescence procedure. Freshly drawn lymphocytes were shown to bear simultaneously i, y, x, and X chain determinants. Experiments combining redistribution induced by antibody and double labeling proved that IgG was bound to surface IgM. After removal of surface immunoglobulins by treatment with trypsin followed by incubation in culture medium, or after redistribution induced by antibody, the exclusive presence of a newly synthetized monoclonal IgM was demonstrated. Several experiments showed that this surface IgM does specifically bind normal human IgG molecules devoid of aggregated material. The IgG molecules could be removed from the cell surface by lowering the pH. In addition to its high incidence among serum monoclonal macroglobulins, anti-IgG activity of membrane-bound monoclonal IgM is not uncommon in patients with chronic lymphocytic leukemia, a disease that provides homogeneous populations of lymphocytes derived from bone marrow, with receptor sites of defined antibody activity.The presence of receptor molecules of immunoglobulin on the surface of lymphocytes derived from bone marrow (B lymphocytes) is well documented in different species including man (1, 2). Since lymphocytes from many patients with chronic lymphocytic leukemia (1, 3, 4) and from patients with Waldenstr6m's macroglobulinemia (5) are characterized by a monoclonal surface IgM marker, these immunoproliferative disorders may provide suitable models for the study of antibody activities of surface immunoglobulins on homogeneous B-lymphocyte populations. In view of the high incidence of antibody activity against IgG among serum monoclonal IgM (6), it appeared logical to search for such an antibody activity of surface monoclonal IgM. We have studied the cells of a patient with Waldenstr6m's macroglobulinemia and known rheumatoid-factor activity of serum monoclonal IgM. Moreover, we have found by immunofluorescence study of living cells the simultaneous presence of Sy-, x-, X-, and usually u-chain determinants on the lymphocytes from several patients with chronic lymphocytic leukemia. One of the possible explanations for this unexpected finding is the anti-IgG activity of surface immunoglobulins. The results presented here clearly show that, in some instances, the monoclonal IgM on the surface of lymphocytes does specifically bind normal human IgG. MATERIALS AND METHODSThe methods used for isolation of lymphoid cells from blood or bone marrow, immunofluorescence study of living cells in suspension, and preparation and characterization of reagents stained with fluorescein or rhodamine that are monospecific for y, lu a, x, and X chains have been described (4, 5). Pooled normal human IgG was purified by chromatography on diethylaminoethyl (DEAE)-cellulose columns and coupled to tetramethylrhodamine isot...

T and B Lymphocytes in Peripheral Blood and Tissue Lesions in Sjögren's Syndrome

“…Because it was felt possible that cell surface immunoglobulins detected by immunofluorescence in these patients might be influenced by cell binding of YG secondary to reaction with cell surface -vM rheumatoid factor in a situation similar to that previously described by Preud'homme and Seligmann (37), several experiments using fluorescein-conjugated aggregated IgG were performed using Sjbgren's patients' lymphocytes showing high percentages of surface IgM. No capping phenomena or positive demonstration of cell surface-bound rheumatoid factor could be conclusively demonstrated using these techniques.…”

Synovial fluid lymphocytes in rheumatoid arthritis

“…Such studies suggested the presence of approximately 10% doubly staining cells in some rheumatoid effusions due to surface IgM rheumatoid factor. Preud'Homme and Seligmann have recorded the presence of membrane-bound monoclonal IgM with rheumatoid factor specificity in patients with chronic lymphocytic leukemia and Waldenstrom's macroglobulinemia, both of which are associated with abnormalities in the maturation of the IgMproducing cell line (8). Membrane-bound rheumatoid factor was not detected by this approach in peripheral blood in RA but could be readily detected in synovial fluid lymphocytes in a small percentage of patients.…”

“…T h e cells were washed three times in RPMI 1640 and incubated at 37°C. After 1 hour the cells were reexamined by immunofluorescence to ensure that trypsinization was complete and that no surface immunoglobulins remained (8). After 6 hours of culture the cells were again studied for surface immunoglobulins and counted as described above.…”

Comparative Study of Bone Marrow and Blood B Cells in Infantile and Acquired Agammaglobulinemia

“…There had been recent interest in searching for circulating anti-Ig that could play a role in the pathogenesis of several lymphoproliferative (12,19,20) and autoimmune diseases (21). Several patients with selective IgA deficiency were found to have in their serum anti-IgMI of the IgG class (22,23).…”