Possible correlation between some biologic effects and the clinical course in patients treated with continuous infusion of interleukin-2 plus alpha-2 interferon for metastatic renal cell carcinoma.

BACKGROUND: Interleukin-2 therapy is known to cause many biologic effects, which are enhanced by the administration of interferon prior to or immediately after interleukin-2 infusion. Some of these effects could be related to the clinical response. METHODS: Sixteen patients with metastatic renal cell carcinoma were treated with continuous infusion of interleukin-2 plus alpha-2 interferon. Differential leukocyte count and lymphocyte subset evaluation were performed every 3 days during interleukin-2 treatment. At each cycle, the presence of the following antibodies was tested: antithyroid, antinuclear, antiplatelet and antierythrocyte. RESULTS: Fifteen patients were evaluable for response. No complete response was observed. Five patients obtained partial response (33%) and 3 stable disease (20%): 2 of them underwent surgical resection of metastases and obtained complete response. Some of our patients showed a significant increase in eosinophils, CD25+ lymphocytes and antithyroid antibodies. The association of these parameters, calculated with a "score" system, was also related to a better clinical response. CONCLUSIONS: Eosinophils, CD25+ lymphocytes and antithyroid antibodies could have a predictive value for the efficacy of interleukin-2 and alpha-2 interferon therapy in metastatic renal cell carcinoma.

Humoral cytotoxicity in melanoma patients and its correlation with the extent and course of the disease.

Complement-dependent cytotoxicity against melanoma cells was demonstrated with a microassay in sera from melanoma patients. The response was tumor-specific and histologic type-specific since 16 out of 52 (30%) melanoma patient sera taken before surgery reacted against melanoma cells, whereas 3 out of 43 (7%) control sera, collected from patients with unrelated tumors and from cancer-free individuals, were positive. The serum activity correlated with the clinical stage of the disease since it was detected in 15 out of 40 patients with stage I and II tumors and in 1 of the 12 patients in stage III. Twelve melanoma patients, clinically tumor-free for to 4 years after surgery, showed no humoral cytotoxicity. A follow-up study of 13 melanoma patients revealed that the cytotoxicity appeared 7-10 days after radical removal of the tumor and that it disappeared if there was no recurrence. The histologic type-specificity was further tested by assaying sera from 16 melanoma and 10 breast-cancer patients simultaneously on both melanoma and breast-cancer cells; a positive reaction was observed in 6 cases of melanoma and in 5 of breast cancer on homologous cells only, in 1 case on the opposite type of cells, and in 3 cases on both types of tumor cells.