Immunologic study of human recombinant interleukin-2 (low-dose) in patients with advanced renal cell carcinoma

Immunologic and antitumor effects of human recombinant interleukin-2 was studied in patients with advanced renal cell carcinoma. Intravenous drip infusion for inpatients or subsequent subcutaneous injection for outpatients at a daily dose of 1 x 10(6) units of interleukin-2 was given over a period varying from twenty-one to two hundred forty days to 13 patients. Natural killer cell activity increased 20 percent or more in 11 of the 13 patients, and lymphokine-activated killer cell activity increased 40 percent or more in 9 of the patients tested. Interleukin-2-receptor positive cells and HLA-DR positive cells in peripheral blood lymphocytes increased in 12 and 11 patients, respectively. Two patients achieved complete response; 1 had a partial response; 6 had no change; and 2 had progressive disease. Two patients were not evaluated because the therapy had been discontinued in less than four weeks. We conclude that low-dose interleukin-2 enhances patients' immunity and has a potential antitumor activity against renal cell carcinoma.