Azathioprine in steroid refractory immune checkpoint inhibitor-induced cholangitis: a case report

Abstract

A 61-year-old man had received 15 cycles of nivolumab, and he was treated with docetaxel for an advanced lung squamous cell carcinoma. Two months later after the final injection of nivolumab, he presented with epigastralgia. Laboratory test showed cholestasis. Abdominal computed tomography with contrast medium showed diffuse wall thickening of extrahepatic duct and ampulla of vater. Endoscopic retrograde cholangiography showed extrahepatic bile duct dilation without obstruction. Histological findings of bile duct biopsy confirmed severe infiltration of lymphocyte, dominantly composed of CD8⁺Tcell in subepithelial tissue. We made the diagnosis of immune checkpoint inhibitor-induced cholangitis by these findings. Because he did not respond to the initial systemic corticosteroid therapy and additional treatment of mycophenolate mofetil, we treated with azathioprine. Cholestasis improved after the administration of azathioprine, then we restarted chemotherapy.