Immune Checkpoint Inhibitor-induced Immune-mediated Hepatitis in A Lung Cancer Patient Undergoing Long-term Immunotherapy: A Case Report

Immune-mediated hepatitis (IMH) induced by immune checkpoint inhibitors (ICIs) is an immune-related adverse event (irAE). IMH usually occurs 8–12 weeks after the first dose of ICI therapy. We report an unusual case of a lung cancer patient who developed IMH 2 years after initial ICI treatment and relapsed during corticosteroid therapy. A 55-year-old male with stage Ⅳ B lung cancer received ICIs (for over 2 years) and chemotherapy as a second-line therapy. Grade 4 IMH occurred 2 years after initial immunotherapy and was diagnosed as hepatitis via laboratory and imaging tests with the simultaneous exclusion of other causes. The patient responded well to the corticosteroids; however, he decided to discontinue treatment prematurely, meaning that the total treatment period was less than 4 weeks. This led to IMH reoccurrence and the need to readminister corticosteroids at a higher dose than before. Ultimately, the patient's IMH was controlled and did not reoccur. This case illustrates that immune-related toxicity needs to be monitored in patients undergoing long-term ICI therapy. Improving patient education is also essential for the management and treatment of irAEs.