title: Use of Orthoclone monoclonal antibodies in the study of selected dermatologic conditions.
abstract: Monoclonal antibodies recognizing human T cell differentiation antigens were used to study lymphocyte populations in three cutaneous diseases. Neoplastic lymphocytes from patients with varying phases of cutaneous T cell lymphoma (mycosis fungoides, Sezary syndrome and related presentations) were reactive with OKT1 and OKT3 (pan T cell reagents) and OKT4 (an antibody defining the functional "helper" T cell subset). The malignant cells lacked membrane antigens reactive with OKT5 and OKT8 (markers of "suppressor" T cells). The presence of an OKT1+, OKT3+, OKT4+, OKT5-, OKT8- phenotype on the neoplastic T lymphocytes of cutaneous T cell lymphoma (CTCL) supports the clinical impression that all phases of CTCL represent a single disease entity. A patient with pemphigus vulgaris, a disease of autoreactive, antiepidermal antibodies was shown to consistently have a marked expansion of the peripheral blood OKT4 reactive T lymphocyte population. These findings suggest that autoantibodies in pemphigus vulgaris may occur in the context of a profound OKT4/OKT5 immunoregulatory imbalance. Peripheral blood lymphocytes from patients ith extensive psoriasis vulgaris had a normal profile of reactivity with the OKT antibodies. In addition, OKT6 (marker of intrathymic T cells) has been shown to react with Ia+ dendritic cells in the epidermis suggesting that this antibody may recognize Langerhans' cells.
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000818:Animals; D000911:Antibodies, Monoclonal; D002471:Cell Transformation, Neoplastic; D003208:Concanavalin A / Q000494:pharmacology; D006801:Humans; D008198:Lymph Nodes / Q000276:immunology; D008214:Lymphocytes / Q000276:immunology*; D008223:Lymphoma / Q000276:immunology; D051379:Mice; D008875:Middle Aged; D010392:Pemphigus / Q000276:immunology; D010641:Phenotype; D011565:Psoriasis / Q000276:immunology; D011817:Rabbits; D012871:Skin Diseases / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D003208:Concanavalin A