title: Ia-like antigens in lichen planus.
abstract: The occurrence of Ia-like antigens in the skin of patients with lichen planus was studied by an indirect immunofluorescence (IIF) technique with use of immunosorbent-purified anti-Ia antibodies. Normal skin from the patients and skin from healthy persons showed dermal histiocytes and epidermal suprabasal dendritic cells expressing these antigens. In lichen planus lesions Ia-like antigens were found on virtually all mononuclear cells in the dermal infiltrate and showed an intercellular pattern in the epidermis. The finding of cells expressing Ia-like antigens in the dermal infiltrate, most probably activated T lymphocytes, renders likely a cell-mediated type of reaction in the pathogenesis of lichen planus.
mesh_terms: D005455:Fluorescent Antibody Technique; D000949:Histocompatibility Antigens Class II / Q000032:analysis*; D006801:Humans; D008010:Lichen Planus / Q000276:immunology* / Q000473:pathology; D012867:Skin / Q000276:immunology / Q000473:pathology; D012871:Skin Diseases / Q000276:immunology
chemical_list: D000949:Histocompatibility Antigens Class II