[A Case of Delayed-Onset Acute Interstitial Nephritis following Nivolumab Treatment in a Patient with Advanced Esophagogastric Junction Cancer].

ABSTRACT

An 81-year-old man with advanced esophagogastric junction cancer with paraaortic lymph node metastasis was treated with S-1 plus oxaliplatin and nivolumab combination chemotherapy. Subsequently, conversion surgery was performed, and the patient was discharged without postoperative complications. Two months after discharge, the patient developed fever, fatigue, and anorexia. Intravenous antibiotic therapy was started; however, the symptoms did not improve. Urine biochemical tests revealed significantly elevated N-acetyl-ß-D-glucosaminidase and ß-microglobulin levels, and acute interstitial nephritis was suspected. Steroid therapy was initiated, and the patient's symptoms improved. A renal biopsy performed at the same time the nivolumab treatment was initiated led to the diagnosis of immune-related interstitial nephritis, a probable adverse event of the treatment. Although immune-related adverse events associated with immune checkpoint inhibitors are typically colitis, interstitial pneumonia, and endocrine disturbances, we observed severe interstitial nephritis in the patient. Clinicians should also consider the possible occurrence of immune-related adverse events >2 months after administering treatment.