MYOSITIS ASSOCIATED WITH INTERLEUKIN-2 THERAPY IN A PATIENT WITH METASTATIC RENAL-CELL CARCINOMA

Background. Interleukin-2 (IL-2) has been used successfully in the tre atment of some patients with metastatic renal cell carcinoma and melan oma, with a partial response rate of 15%-20%. It produces a well docum ented spectrum of side effects. Autoimmune diseases have been associat ed with IL-2 immunotherapy and the development of autoimmune thyroidit is may correlate with antitumor clinical response. Methods. A patient with metastatic renal cell carcinoma is described who developed a poly myositis-like myopathy after an autologous tumor vaccine and IL-2 ther apy. Results. The patient had a delayed response for 15 months after d eveloping this previously unreported toxicity. Conclusions. To the aut hors' knowledge, this represents the first reported case of necrotizin g myositis in association with IL-2 therapy. Subsequent continuous par tial response of the advanced malignancy was observed for 15 months. I n this case, IL-2 may have broken tolerance to both normal muscle cell s and tumor cells.