The effects of azathioprine and levamisole on rosette-forming cells of healthy subjects and cancer patients.

The in vitro effects of azathioprine and levamisole on the capacity of peripheral lymphocytes to form rosettes with sheep erythrocytes were studied in fifteen healthy subjects and forty-one cancer patients. Azathioprine significantly inhibited rosette formation of T lymphocytes in healthy subjects and cancer patients in remission. In contrast, azathioprine could not inhibit rosette formation of T lymphocytes in cancer patients with advanced disease. Patients with advanced tumour had also fewer rosette-forming cells (RFC) than healthy subjects. Levamisole, an anti-anergic chemotherapeutic agent, restored azathioprine-inhibited RFC in healthy subjects and in fifteen out of twenty-two cancer patients. Levamisole alone significantly enhanced low RFC in cancer patients.