T-cell subsets in cutaneous sarcoidosis.

Skin lesions from four patients with systemic and cutaneous sarcoidosis were studied, by the use of monoclonal antibodies, for the presence of T cells and T-cell subsets. Large numbers of lymphoid cells reacting with anti-pan T-cell (LEU-1) and anti-helper and inducer subset (LEU-3) monoclonal antibodies were observed around and within the sarcoid granulomas in three of the four patients. Only rare LEU-2-reactive suppressor cells were observed in all four patients. Activated T lymphocytes with focal acid phosphatase activity, together with epithelioid cells and multinucleated giant cells with strong diffuse activity of acid phosphatase and nonspecific esterase, were identified within the granulomas. The two patients with active disease demonstrated substantially more T cells in the sarcoid granulomas than did the two patients with chronic disease. Our study results suggest the importance of helper T cells in the formation of the sarcoid granuloma by mononuclear phagocytes and imply that the activity and duration of disease may be related to the T-cell populations.