[INTERSTITIAL NEPHRITIS CAUSED BY IPILIMUMAB AND NIVOLUMAB COMBINATION THERAPY FOR ADVANCED RENAL CELL CARCINOMA: A CASE REPORT].

The patient was 74-year-old woman. She underwent open nephrectomy for right kidney cancer with multiple lung metastasis in June X, and was diagnosed as clear cell renal cell carcinoma, pT3bN0M1. Combination therapy with ipilimumab and nivolumab was started in July X. In September X, she presented our hospital with the chief complaint of anorexia. The renal function deteriorated remarkably with serum Cr of 8.58 mg/dL and BUN of 71 mg/dL. CT scan revealed an enlarged left kidney at that time. She was clinically diagnosed as Grade 3 interstitial nephritis caused by immune checkpoint inhibitor, and treatment was initiated immediately. She was treated with steroid therapy and discontinuation of the drugs she was taking, which gradually improved her renal function, and brought it back to baseline in three weeks. After that, the steroid was carefully tapered, and turned off on day 52, and nivolumab monotherapy was resumed on day 60. After five cycles of nivolumab monotherapy, there has been no recurrence of interstitial nephritis, and the disease remains stable. In Japan, 38 cases of interstitial nephritis due to immune checkpoint inhibitors have been reported. In most cases, the diagnosis was made by histological examination; however, we believe that the diagnosis should be made clinically and treatment should be started immediately, since the early treatment is important for immune-related adverse events.