title: Stress deficiency of the T-lymphocyte system exemplified by Down syndrome.
abstract: A comparison of immune competence in 26 patients with Down syndrome in an institution and 26 matched healthy controls revealed an atypical pattern of T-cell immunodeficiency in the Down-syndrome patients. The patients with Down syndrome had a lymphocytosis in blood with high counts of T (and B) cells, but with impaired effector function of T cells as judged by anergy to dinitrochlorobenzene, low responsiveness to ubiquitous antigens which elicit delayed-type hypersensitivity reactions, and low mitogenic activity of non-stimulated and phytohaemagglutinin-stimulated lymphocytes in culture. Helper-T-cell function measured by the humoral immune response to flagellin was intact, and there were minor abnormalities of the B-cell system. Attempted restoration of T-cell function with levamisole was unsuccessful. This pattern of T-lymphocytosis with impaired effector function could be explained by "stress-deficiency" of the immune system consequent upon a heavy load of infection in early life.
mesh_terms: D000293:Adolescent; D000328:Adult; D001323:Autoantibodies / Q000302:isolation & purification; D001402:B-Lymphocytes / Q000473:pathology; D004314:Down Syndrome / Q000276:immunology*; D005260:Female; D006801:Humans; D007136:Immunoglobulins / Q000032:analysis; D007153:Immunologic Deficiency Syndromes / Q000175:diagnosis / Q000188:drug therapy / Q000209:etiology*; D007158:Immunologic Techniques; D007958:Leukocyte Count; D007978:Levamisole / Q000627:therapeutic use; D008218:Lymphocytosis / Q000097:blood / Q000209:etiology; D008297:Male; D008875:Middle Aged; D010919:Placebos; D013312:Stress, Physiological / Q000150:complications / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology / Q000473:pathology
chemical_list: D001323:Autoantibodies; D007136:Immunoglobulins; D010919:Placebos; D007978:Levamisole