Clinical Characteristics and Predictive Factors of Immune-Mediated Cholangitis: A Large Single-Center Retrospective...

Immune-mediated cholangitis (IMC) is a rare complication of immune checkpoint inhibitor (ICI) therapy, and its clinical characteristics and prognostic implications remain unclear. This study aimed to clarify the characteristics, risk factors, and outcomes of IMC compared with non-cholangitis cases of immune-mediated hepatotoxicity (IMH).

In this single-center retrospective study, 1332 patients who received ICIs between 2014 and 2023 were analyzed. IMH was diagnosed based on liver enzyme elevation and exclusion of other liver diseases, while IMC was identified through characteristic imaging findings. Baseline factors, clinical presentations, treatment responses, and overall survival (OS) were evaluated. Multivariate analysis identified IMC risk and IMH prognostic factors.

Among the cohort, 81 (6.1%) patients had IMH, including 10 (0.8%) with IMC. Baseline eosinophil count > 270/μL (odds ratio [OR] 10.33, p = 0.004) and C-reactive protein (CRP) levels > 0.8 mg/dL (OR 6.260, p = 0.027) were independent predictors of IMC. IMC was associated with delayed onset, cholestatic liver injury, abdominal pain, and neutrophil-predominant inflammation. In prognostic analysis, IMC was not associated with OS. However, cholestatic liver injury (hazard ratio [HR] 2.318, p = 0.023) and neutrophil-to-lymphocyte ratio (NLR) ≥ 4.0 (HR 3.622, p = 0.001) were independent predictors of poor OS. Bile duct imaging abnormalities before or after onset were common in patients with treatment-resistant IMC.

Baseline eosinophil count and CRP may help predict IMC. While IMC was not a prognostic factor, cholestatic injury and high NLR were associated with worse outcomes. IMC exhibits distinct clinical features, and radiologic findings may support earlier diagnosis and management.