title: T-cell infiltrate in lichen planus. Demonstration of activated lymphocytes using monoclonal antibodies.
abstract: Double layer immunocytochemical procedures were performed on fresh frozen serial sections of lichen planus (LP), using three monoclonal antibodies: OKT3 (T-cells) and two anti Ia-like antigens, monoclonal antibodies. Lymphocytes in dermal LP infiltrates were OKT3 positive and Ia-like positive; lymphocytes in the paracortical area of human normal lymph-node were OKT3 positive and Ia-like negative. Unstimulated peripheral blood-OKT3 positive, E-rosette forming cells of normal donors were Ia-like negative, while the same T-cells, when mitogen-stimulated, became Ia-like positive. Therefore, in dermal infiltrates of LP, T-lymphocytes are Ia-like positive cells, representing an antigen-stimulated T-cell population. The in situ presence of activated T-lymphocytes seems to support the hypothesis of an immunological nature of LP.
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology*; D001706:Biopsy; D006801:Humans; D008010:Lichen Planus / Q000276:immunology*; D008198:Lymph Nodes / Q000276:immunology; D008213:Lymphocyte Activation; D012867:Skin / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal