Natural and antibody-dependent cellular cytotoxicity in patients with active sarcoidosis

Lymphocyte surface markers, natural killer activity, antibody-dependent cellular cytotoxicity and lymphocyte binding to target cells were evaluated in a group of 16 subjects with active sarcoidosis. A reduction of E-RFC and a relative increase of EA-RFC were observed. At the same time, ADCC activity was similar to that of normal controls, while NK cytotoxicity was significantly decreased. On the other hand, the percentage of conjugates between lymphocytes and target cells was lower than in controls. These observations account for a selective defect of NK activity, suggesting that the NK assay might be an useful tool to support the impairment of cellular immunity in active sarcoidosis.