[Immunological study of interferon-gamma therapy for advanced renal cell carcinoma]

Immunologic and anti-tumor effects of interferon-gamma were studied in six patients with advanced renal cell carcinoma. A daily dose of 10 x 10(6) JRU/m2 of interferon-gamma (IFN-gamma) was given consecutively for five days and the treatment reiterated nine days later. Then the same dose was given every two days for three times and this regimen was also reiterated nine days later. Peripheral blood lymphocytes were analyzed before and one, three, five and eight weeks after the initial administration of IFN-gamma. Although the total number of lymphocytes and monocytes were not changed, CD8 (23.4 to 31.2%, p < 0.05), CD16 (12.4 to 19.3%, p < 0.01) and LeuHLA-DR (29.0 to 39.5%, p < 0.01) positive lymphocytes were significantly increased after the therapy. Non-induced LAK activity (0.6 to 10.8%, p < 0.05) and serum neopterin (3.5 to 10.8 nmol/L, p < 0.01) were also increased. These immunological parameters drastically changed during the consecutive administration of IFN-gamma, and tended to return to the previous value after this period. However, tumor regression was not clinically obtained. Our findings indicate that interferon-gamma stimulated the anti-tumor activity of the host, and administration of IFN-gamma is thought to be of immunological significance even in the advanced high stage cases.