title: Imbalances in T cell subpopulations associated with immunodeficiency and autoimmune syndromes.
abstract: Abnormal proportions of the distinct T cell subpopulations binding the Fc portion of IgM (T-M) cells and those bearing receptors for the Fc portion of IgG (T-G) cells, were observed in blood samples from patients who had congenital or acquired abnormalities of the thymus, severe combined immunodeficiency, or an unexplained primary deficiency in cell-mediated immunity; most had too few circulating T-M cells and often an overabundance of T-G cells. In an in vitro evaluation of lymphocyte from one of three thymoma patients with an elevated T-G subpopulation, removal of T-G cells abrogated the suppression of T-M cell help of B cell differentiation induced by pokeweed mitogen. A spectrum of patients with sex-linked infantile agammaglobulinemia, variable hypogammaglobulinemia, and selective IgA deficiency, and a few patients with autoimmune syndromes infrequently had distorted representation of these T cell subpopulations in the circulation. This suggests that B cell dysfunction in many of these patients is not merely due to numerical excesses or insufficiencies of helper or suppressor T cells.
mesh_terms: D001327:Autoimmune Diseases / Q000276:immunology*; D001402:B-Lymphocytes / Q000276:immunology; D002469:Cell Separation; D006801:Humans; D007141:Immunoglobulin Fc Fragments; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D007153:Immunologic Deficiency Syndromes / Q000150:complications / Q000276:immunology*; D007958:Leukocyte Count; D013577:Syndrome; D013601:T-Lymphocytes / Q000276:immunology*; D013945:Thymoma / Q000150:complications; D013950:Thymus Gland / Q000276:immunology; D013953:Thymus Neoplasms / Q000150:complications
chemical_list: D007141:Immunoglobulin Fc Fragments; D007074:Immunoglobulin G; D007075:Immunoglobulin M