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

Abstract

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.