title: Heterogeneity of immunological abnormalities in ataxia-telangiectasia.
abstract: Peripheral blood mononuclear cells from five patients with ataxia-telangiectasia were evaluated for their reactivity with a panel of monoclonal antibodies directed against T-cell subsets and for their in vitro functions in a pokeweed mitogen-induced immunoglobulin biosynthesis assay. All the patients had significantly reduced proportions of cells identified by monoclonal antibodies to subpopulations of T lymphocytes with helper activity (OKT4 and 5/9) and produced low amounts or no IgA and IgG in vitro. Immunoglobulin biosynthesis was increased by the addition of normal x-irradiated peripheral blood mononuclear cells in one of three patients, suggesting a helper T-cell deficiency in this patient and intrinsic B-cell defects in the other two. Two patients had increased proportions of cells identified by a monoclonal antibody to a subpopulation of T lymphocytes which includes suppressor T cells (OKT8), and their cells were able to suppress immunoglobulin biosynthesis by peripheral blood mononuclear cells from normal donors. These findings indicate heterogeneous disturbances of immunoregulatory mechanisms in ataxia-telangiectasia.
mesh_terms: D000293:Adolescent; D000328:Adult; D000910:Antibodies, Heterophile / Q000502:physiology*; D000911:Antibodies, Monoclonal / Q000502:physiology; D001260:Ataxia Telangiectasia / Q000276:immunology*; D001402:B-Lymphocytes / Q000502:physiology; D002648:Child; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007136:Immunoglobulins / Q000096:biosynthesis; D066298:In Vitro Techniques; D008297:Male; D006377:T-Lymphocytes, Helper-Inducer / Q000502:physiology; D050378:T-Lymphocytes, Regulatory / Q000502:physiology
chemical_list: D000910:Antibodies, Heterophile; D000911:Antibodies, Monoclonal; D007136:Immunoglobulins