title: Multiple myeloma: an immunologic profile. IV. The EA rosette-forming cell is a Leu-1 positive immunoregulatory B cell.
abstract: Patients with myeloma have a depressed capacity to respond to antigenic challenge. Studies in this laboratory have previously described an unclassified lymphoid cell which binds human erythrocytes coated with human immunoglobulin G (IgG) anti-D antibody (EA) as important in the inhibition of Ig synthesis in myeloma patients. Using monoclonal antibodies, two-color fluorescence studies, and flow cytometry, we characterized this EA cell as a Leu-1+ (cluster designation (CD) 5), Leu-12+ (CD 19), Leu-16+ (CD 20), B2+ (CD 21), Leu-14+ (CD 22), and HLA-DR+ B cell. The cell was negative for antibodies to Leu-2 (CD 8), Leu-3 (CD 4), Leu-4 (CD 3), Leu-5 (CD 2), Leu-7, Leu-8, Leu-11 (CD 16), Leu-M1 (CD 15), Leu-M3, and CALLA (CD 10). This profile is consistent with a Leu-1+ B cell and excludes a T cell, natural killer cell, and monocyte. Comparison of the relative role of these cells to the role of monocytes in the suppression of pokeweed mitogen-stimulated Ig synthesis was determined in serial studies on 19 myeloma patients. The mean (+/- SEM) percentage of inhibition of Ig synthesis by monocytes from stage I myeloma patients was 14 +/- 2.2%, from stage II patients was 37 +/- 3.5%, and from stage III patients was 51 +/- 4.7%. Inhibition of Ig synthesis by Leu-1+ EA cells was 46 +/- 1.5%, 48 +/- 1.6%, and 43 +/- 3.7% in stage I, II, and III patients, respectively. Immunosuppressive B cells are an important component of inhibition of Ig synthesis in the immunodeficiency of myeloma.
mesh_terms: D000911:Antibodies, Monoclonal; D000917:Antibody Formation; D000944:Antigens, Differentiation, B-Lymphocyte; D000954:Antigens, Surface / Q000032:analysis*; D001402:B-Lymphocytes / Q000145:classification / Q000276:immunology*; D004912:Erythrocytes / Q000276:immunology; D005434:Flow Cytometry; D006801:Humans; D007072:Immunoglobulin D / Q000276:immunology; D007074:Immunoglobulin G / Q000276:immunology; D009101:Multiple Myeloma / Q000276:immunology*; D012397:Rosette Formation; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D000944:Antigens, Differentiation, B-Lymphocyte; D000954:Antigens, Surface; D007072:Immunoglobulin D; D007074:Immunoglobulin G