title: Pre-B cells in peripheral blood of multiple myeloma patients.
abstract: Although multiple myeloma is a disease of plasma cells, abnormalities have been detected in both B and T lymphocytes in peripheral blood. Although multiple myeloma patients are deficient in surface Ig (sIg)-positive B lymphocytes, analysis of lymphocytes present in blood indicates an abnormally large pool of circulating pre-B cells. These pre-B cells express BA-1, do not bear sIg, and contain cytoplasmic mu chains. High numbers of pre-B cells occur in 88% of individuals with frank myeloma and in 44% of individuals with monoclonal gammopathy of undetermined significance. Pre-B cells bearing BA-1 differ between patients in their expression of HLA-DR and receptors for peanut agglutinin (PNA). Those pre-B cells in myeloma patients are either BA-1+ PNA- HLA-DR+ (54% of patients) or BA-1+ PNA+ HLA-DR- (30% of patients), or have a mixture of phenotypes (14% of patients). Pre-B cells of the PNA- phenotype are almost always HLA-DR+, and PNA+ pre-B cells are HLA-DR-. Within the same patient, the pre-B cell population varies by both quantitative and qualitative definitions. The number of pre-B cells may increase 460-fold and temporal shifts of surface phenotype from BA-1+ PNA- to BA-1+ PNA+ or vice versa have been detected. These observations indicate an abnormality in the B lymphocyte differentiation pathway leading to pre-B cells in the periphery that vary in number and cell surface phenotype, and that are unable to express sIg.
mesh_terms: D000911:Antibodies, Monoclonal; D001402:B-Lymphocytes / Q000276:immunology*; D005455:Fluorescent Antibody Technique; D006684:HLA-DR Antigens; D000949:Histocompatibility Antigens Class II / Q000032:analysis; D006801:Humans; D006942:Hypergammaglobulinemia / Q000276:immunology; D007136:Immunoglobulins / Q000276:immunology; D007958:Leukocyte Count; D008565:Membrane Proteins / Q000276:immunology; D008875:Middle Aged; D009101:Multiple Myeloma / Q000276:immunology*; D010641:Phenotype; D011975:Receptors, Mitogen / Q000032:analysis
chemical_list: D000911:Antibodies, Monoclonal; D006684:HLA-DR Antigens; D000949:Histocompatibility Antigens Class II; D007136:Immunoglobulins; D008565:Membrane Proteins; D011975:Receptors, Mitogen; C038223:peanut agglutinin receptor