Prevalence and outcomes of acute presentations of autoimmune hepatitis: Systematic Review and Meta-Analysis

Acute presentations of autoimmune hepatitis (AIH) ranging from acute hepatitis to acute liver failure (ALF) and acute-on-chronic liver failure (ACLF) are diagnostically challenging and clinically heterogeneous. We performed a systematic review and meta-analysis to determine the prevalence of acute AIH presentations and to evaluate transplant-free survival (TFS) across subtypes.

We searched PubMed, Embase, Web of Science, Scopus, and the Cochrane Library from inception through July 2025 for observational studies reporting acute AIH presentations. Random-effects models generated pooled prevalence and TFS estimates, with a general/unselected-cohort sensitivity analysis performed where feasible. Study quality was assessed using the JBI checklist.

Across 10 studies reporting both a total AIH cohort size and a separately quantified acute presentation, the pooled proportion of AIH patients presenting acutely was 39% (95% CI 27%-54.0%; I²=95%). Thirty-four studies were included to describe different acute phenotypes. The pooled prevalence of acute non-severe AIH (ANS-AIH), acute severe AIH (AS-AIH), AIH-associated ALF, acute/severe exacerbation of chronic AIH, and AIH-associated ACLF was 21% (95% CI, 14%-30%; I²=75.6%), 15.0% (95% CI, 9%-23%; I²=79.4%), 3% (95% CI, 1%-9%; I²=90.1%), 15% (95% CI, 9%-25%; I²=91.8%), and 11% (95% CI, 7%-16%; I²=78.5%), respectively. TFS was standardized to 90-day timepoint where feasible. Pooled 90-day TFS was 79% (95% CI 36-96%; I²=0%) for AS-AIH and 19% (11%-31%; I²=0%) for AIH-ALF. Heterogeneity remained substantial across most phenotypes.

Acute presentations are common in AIH and span phenotypes with profoundly different clinical trajectories. While most patients with ANS-AIH, acute/severe exacerbations and AS-AIH achieve favorable outcomes with timely therapy, progression to ALF carries poor TFS.