Subpopulations of mononuclear cells in lesions of psoriasis, lichen planus and discoid lupus erythematosus studied using monoclonal antibodies.

Mononuclear cells in skin lesions were characterized using an indirect immunofluorescence test with monoclonal antibodies. Most cells in the dermal infiltrates were stained with OKT3 (pan T cell) antibodies and with OKT4 (helper/inducer T cell) antibodies. Fewer cells were stained with OKT8 (suppressor/cytotoxic T cell) antibodies. Results obtained using a double marking technique with monoclonal antibodies and a hetero-anti-T lymphocyte serum showed that suppressor/cytotoxic cells comprised 15-25% of the T lymphocytes in lesions of psoriasis and discoid lupus erythematosus (DLE), and 25-35% in lesions of lichen planus. OKM1 (monocyte) antibodies stained few of the infiltrating cells in sections of the various skin lesions. The highest numbers of OKM1+ cells were found in sections of lesional skin from patients with erythrodermic and pustular psoriasis. Some T lymphocytes were also demonstrated in the epidermis in the various skin lesions. The highest numbers were found in the psoriatic lesions. The epidermal T lymphocytes were mainly suppressor/cytotoxic cells, and may be involved in a cell-mediated immune reaction of importance in the pathogenesis of these dermatoses.