Workup and Management of Immune-Mediated Hepatobiliary Pancreatic Toxicities That Develop During Immune Checkpoint Inhibitor Treatment.

Immune checkpoint inhibitor treatment has been approved by the U.S. Food and Drug Administration for the treatment of a wide range of cancer types, including hepatocellular carcinoma. Workup and management of immune-mediated hepatitis, pancreatitis, or cholangitis that develops during immune checkpoint inhibitor treatment can be challenging. Immune-mediated hepatitis can be particularly challenging if patients have underlying viral hepatitis or autoimmune hepatitis. Patients with positive hepatitis B virus DNA should be referred to a hepatologist for antiviral therapy prior to immune checkpoint inhibitor treatment. With untreated hepatitis C virus (HCV) and elevated liver enzymes, a liver biopsy should be obtained to differentiate between HCV infection and immune-mediated hepatitis due to anti-programmed cell death protein 1 (PD-1) therapy. If autoimmune serologies are negative, then this supports a case of immune-mediated hepatitis secondary to anti-PD-1 therapy, rather than autoimmune hepatitis. In this case, an empiric steroid therapy is reasonable; however, if the patient does not respond to steroid therapy in 3-5 days, then liver biopsy should be pursued. The incidence of immune checkpoint-induced pancreatitis is low, but when it does occur, diagnosis is not straightforward. Although routine monitoring of pancreatic enzymes is not generally recommended, when pancreatitis is suspected, serum levels of amylase and lipase should be checked. Once confirmed, a steroid or other immunosuppressant (if steroids are contraindicated) should be administered along with close monitoring, and a slow tapering dosage once the pancreatitis is under control. Patients should then be monitored for recurrent pancreatitis. Finally, immune therapy-related cholangitis involves elevated bilirubin and alkaline phosphatase and, once diagnosed, is managed in the same way as immune-mediated hepatitis. KEY POINTS: Immune-mediated hepatitis, pancreatitis, and cholangitis are found in patients receiving or who have previously received immune checkpoint inhibitors. To work up immune-mediated hepatitis, viral, and autoimmune serologies, liver imaging will help to differentiate immune-mediated hepatitis from hepatitis of other etiology. Hepatology consult may be considered in patients with a history of chronic liver disease who developed hepatitis during immune checkpoint inhibitor treatment. Liver biopsy should be considered to clarify the diagnosis for case in which the hepatitis is refractory to steroid or immunosuppressant treatment. Immune-mediated pancreatitis is treated with steroid or other immunosuppressant with a slow tapering and should be monitored for recurrence.