[Clinical and pathological characteristics of immune-mediated liver injury caused by immune checkpoint inhibitors].

Objective: Cancer immunotherapy can lead to various side effects, termed immune-related adverse events (irAE). This study summarized and analyzed the clinical and pathological characteristics of immune-mediated liver injury caused by immune checkpoint inhibitors (ILICI). Methods: This is a retrospective case series study involving 11 patients diagnosed with ILICI at the Peking Union Medical College Hospital from November 2019 to November 2021. Patient demographic information and clinical data, including gender, age, ILICI onset, clinical and radiological manifestations, pathological features, treatment, and resumption of ICI were retrospectively collected and analyzed. Results: The patients were primarily males (9/11) with a median age of 65 (range: 32-73) years. ICI mainly resulted in either partial remission (4/11) or stable disease (3/11). ILICI occurred after a median of two cycles of anti-programmed cell death-1 (PD-1) therapy, with a median time from the initial and last anti-PD-1 therapy to ILICI onset of 57 days and 17 days, respectively. ILICI was mostly severe (3/11) or very severe (6/11). While the clinical and radiological manifestations were non-specific, the pathological features were active lobular hepatitis and portal inflammation, with prominent CD8⁺T lymphocyte infiltration. The basic treatment was hepatoprotective drugs (10/11). Glucocorticoids were used as the primary therapy (9/11) but were ineffective in 4 of 9 cases. Of these, 3 of 9 cases received combined treatment with mycophenolate mofetil (MMF), only one of whom achieved remission. By the end of the study, 2 of 11 cases had resumed ICI and neither had experienced an ILICI relapse. Conclusion: The ILICI patients in this study had a corresponding history of ICI treatment and pathological features. The main treatment included hepatoprotective drugs and glucocorticoids. Immunosuppressive drugs were added for some cases but had poor efficacy.