The diagnostic use of monoclonal antibodies in a variety of dermatologic conditions.

Monoclonal antibodies have been used to characterize subpopulations of lymphocytes in a variety of dermatologic conditions by immunofluorescence and immunoperoxidase staining. Various clinical presentations of cutaneous T-cell lymphoma have been shown to be neoplastic expansions of helper T-lymphocytes. Immunoperoxidase studies using subset-specific monoclonal antibodies have allowed the differentiation of patients with cutaneous T-cell lymphoma from lymphocytoma cutis and B-cell lymphomas secondarily involving the epidermis. Increased numbers of OKT-6 positive Langerhans' cells in the dermal infiltrates of patients with cutaneous T-cell lymphoma may be another immunocytological marker of this disease. Studies done on circulating lymphocytes of patients with psoriasis and pemphigus vulgaris have shown normal ratios of T-cell subsets in patients with psoriasis and an expansion of the helper T-cell subset in an untreated patient with pemphigus. Immunofluorescence and immunoperoxidase techniques used in conjunction with highly specific monoclonal antibodies have been shown to be valuable for histopathologic study of dermatologic diseases.