Lack of complete biochemical response in autoimmune hepatitis leads to adverse outcome: first report of the IAIHG retrospective registry

Background and aim: The International Autoimmune hepatitis (AIH) Group retrospective registry (IAIHG-RR) is a web-based platform with subjects enrolled with a clinical diagnosis of AIH. As prognostic factor studies with enough power are scarce, this study aimed to ascertain data quality and identify prognostic factors in the IAIHG-RR cohort. Methods: This retrospective, observational, multicenter study included all patients with a clinical diagnosis of AIH from the IAIHG-RR. Quality assessment consisted of external validation of completeness and consistency for 29 pre-defined variables. Cox regression was used to identify risk factors for liver-related death and liver transplantation (LT). Results: This analysis included 2559 patients across 7 countries. In 1700 patients, follow-up was available, with a completeness of individual data of 90% (range 30-100). During a median follow-up period of 10 (range 0-49) years, there were 229 deaths, of which 116 were liver-related and 143 patients underwent LT. Non-white ethnicity (HR 4.1 95% CI 2.3-7.1), cirrhosis (HR 3.5 95% CI 2.3-5.5), variant syndrome with primary sclerosing cholangitis (PSC) (HR 3.1 95% CI 1.6-6.2), and lack of complete biochemical response within 6 months (HR 5.7 95% CI 3.4-9.6) were independent prognostic factors. Conclusion: The IAIHG-RR represents the world's largest AIH cohort with moderate-to-good data quality and a relevant number of liver-related events. The registry is a suitable platform for patient selection in future studies. Lack of complete biochemical response to treatment, non-white ethnicity, cirrhosis and PSC-AIH were associated with liver-related death and liver transplantation.