title: T cell subpopulations in alopecia areata.
abstract: Alopecia areata remains a disease of unknown cause and unsatisfactory treatment. Histologically it is characterized by a lymphocytic infiltrate that surrounds the lower half of the hair follicle. Our findings show that 64% to 92% of this infiltrate is composed of T lymphocytes bearing the Leu 3a (helper-inducer) phenotype. The remaining lymphocytes demonstrate the Leu 2a (cytotoxic-suppressor) phenotype. This helper T cell predominance is present in all patients, irrespective of clinical activity or duration of disease. The Leu 3a/Leu 2a ratio ranged from 2.6 to 19.8, the higher ratios being seen in patients with clinically active disease. The cutaneous infiltrate also is Ia-positive, indicating the activated nature of these lymphocytes.
mesh_terms: D000328:Adult; D000506:Alopecia Areata / Q000276:immunology* / Q000473:pathology; D000911:Antibodies, Monoclonal / Q000276:immunology; D002648:Child; D005260:Female; D005455:Fluorescent Antibody Technique; D006197:Hair / Q000473:pathology; D006801:Humans; D007111:Immunity, Cellular; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D012535:Scalp / Q000473:pathology; D013601:T-Lymphocytes / Q000145:classification* / Q000473:pathology
chemical_list: D000911:Antibodies, Monoclonal