Immune-mediated liver injury caused by immune checkpoint inhibitors exhibits distinct clinical features that differ from autoimmune hepatitis.

Background: Immune-mediated liver injury caused by immune checkpoint inhibitors (ILICI) and autoimmune hepatitis (AIH) are both related to the distorted immune system. However, ILICI differs from AIH in several distinct ways. We aimed to study the differences between ILICI and AIH.

Research design and methods: This is a retrospective study collecting clinical data of ILICI (2016.1-2024.2) and AIH (2002.1-2023.6) patients. Demographic, clinicopathological, radiological characteristics, treatment and outcomes were analyzed.

Results: A total of 71 ILICI and 158 AIH cases were included. ILICI group had older patients and fewer females (age: 66 vs. 56 years, gender: 28.2% vs. 85.4%, p < 0.001). They had lower ALT, AST, TBil, IgG levels, and lower titers of ANA. Some ILICI patients exhibited bile duct edema and dilation, while AIH patients typically had liver fibrosis in CT/MRI. Histologically, ILICI showed bile duct injury, inflammatory cells infiltration with fewer plasma cells. Glucocorticoid treatment was less common, but ALT level recovery was faster in ILICI patients (41 vs. 140 days, p < 0.001).

Conclusions: ILICI generally affects older patients without a female predilection and is linked to milder, acute liver injury. High ANA titers, elevated IgG, and prominent plasma cell infiltration were less common. Liver function normalizes more quickly in ILICI.