Steroid-refractory immune related hepatitis may hide viral re-activation.

Cancer immunotherapy has become a stronghold in modern oncology. Immune checkpoint inhibitors, in particular anti-PD-1 and anti-PD-L1 antibodies, are approved for the treatment of several solid cancers. In the near future, an increasing number of patients will be eligible for immunotherapy. Therefore, the management of immune-related adverse events is a daily challenge in clinical practice, among which hepatic immune-related toxicity has been described as a rare adverse event. We report the case of a patient treated with nivolumab (an anti-PD-L1 antibody) for a stage IV resected melanoma who developed recurrence of steroid-refractory liver toxicity that was later discovered to be associated with acute exacerbation of chronic undiagnosed hepatitis B. The patient significantly benefited from antiviral treatment. We conclude that serological viral screening is strongly recommended before starting immune checkpoint inhibitor treatment.