Treatment response and clinical event-free survival in autoimmune hepatitis: A Canadian multicentre cohort study

Background & Aims: Treatment outcomes for people living with autoimmune hepatitis (AIH) are limited by a lack of specific therapies, as well as limited well-validated prognostic tools and clinical trial endpoints. We sought to identify predictors of outcome for people living with AIH. Methods: We evaluated the clinical course of people with AIH across 11 Canadian centres. Biochemical changes were analysed using linear mixed-effect and logistic regression. Clinical outcome was dynamically modelled using time-varying Cox proportional hazard modelling and landmark analysis. Results: In 691 patients (median age 49 years, 75.4% female), with a median follow-up of 6 years (25th-75th percentile, 2.5-11), 118 clinical events occurred. Alanine aminotransferase (ALT) normalisation occurred in 63.8% of the cohort by 12 months. Older age at diagnosis (odd ratio [OR] 1.19, 95% CI 1.06-1.35) and female sex (OR 1.94, 95% CI 1.18-3.19) were associated with ALT normalisation at 6 months, whilst baseline cirrhosis status was associated with reduced chance of normalisation at 12 months (OR 0.52, 95% CI 0.33-0.82). Baseline total bilirubin, aminotransferases, and IgG values, as well as initial prednisone dose, did not predict average ALT reduction. At baseline, older age (hazard ratio [HR] 1.25, 95% CI 1.12-1.40), cirrhosis at diagnosis (HR 3.67, 95% CI 2.48-5.43), and elevated baseline total bilirubin (HR 1.36, 95% CI 1.17-1.58) increased the risk of clinical events. Prolonged elevations in ALT (HR 1.07, 95% CI 1.00-1.13) and aspartate aminotransferase (HR 1.13, 95% CI 1.06-1.21), but not IgG (HR 1.01, 95% CI 0.95-1.07), were associated with higher risk of clinical events. Higher ALT at 6 months was associated with worse clinical event-free survival. Conclusion: In people living with AIH, sustained elevated aminotransferase values, but not IgG, are associated with poorer longterm outcomes. Biochemical response and long-term survival are not associated with starting prednisone dose. (c) 2024 The Authors. Published by Elsevier B.V. on behalf of European Association for the Study of the Liver. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).