Abstract and Introduction
Background and Aims: Autoimmune hepatitis (AIH) is a chronic inflammatory liver disease associated with an increased prevalence of extrahepatic autoimmune diseases and an increased mortality compared with the general population. The contribution of extrahepatic autoimmune diseases to the increased mortality has not been clarified. Our aim was to determine the effect of extrahepatic autoimmune diseases on mortality in AIH patients.
Methods: This nationwide register-based cohort study included all Danish patients diagnosed with AIH between 1995 and 2019. We examined the presence of extrahepatic autoimmune diseases and compared the mortality between AIH patients with and without extrahepatic autoimmune diseases. We adjusted our analysis for age, sex, calendar year of AIH diagnosis, cirrhosis, cancer, chronic obstructive pulmonary disease and ischaemic heart disease.
Results: We included 2479 AIH patients of whom 19.8% had one extrahepatic autoimmune disease and 3.3% had multiple. The adjusted 10-year cumulative mortality was 27.2% (95% confidence interval [CI]: 25.2–29.4) for patients with extrahepatic autoimmune diseases and 21.6% (95% CI: 19.9–23.6) for patients without. The adjusted mortality hazard ratio was 1.30 (95% CI: 1.12–1.52) for AIH patients with versus without extrahepatic autoimmune diseases; it was 1.25 (95% CI: 1.06–1.48) for patients with one extrahepatic autoimmune disease and 1.54 (95% CI: 1.15–2.05) for those with more than one.
Conclusions: Extrahepatic autoimmune diseases increased the mortality in patients with AIH. Patients with multiple extrahepatic autoimmune diseases had a higher mortality than patients with just one extrahepatic autoimmune disease.
Autoimmune hepatitis (AIH) is a chronic inflammatory liver disease associated with an increased prevalence of extrahepatic autoimmune diseases (EADs)[1–11] and with an increased mortality compared with the general population.[12–14] However, it is unclear whether EADs contribute to the observed increase in mortality for patients with AIH. Only one study assessed the mortality of patients with AIH comparing those with and without EADs. Wong et al. included a cohort of 562 patients from two tertiary centres. The study found no statistically significant difference in mortality in AIH patients with or without EADs. Moreover, Wong et al. did not evaluate the effect of multiple EADs on mortality, the authors did not present confounder-adjusted analyses of the association between EADs and mortality, and it is unclear whether EADs diagnosed after AIH were included in the survival analysis. Therefore, the question about the effect of EADs on mortality remains unsettled. The answer to that question is important for our understanding of the clinical course of AIH and will enable clinicians to respond to patients' concerns about EADs' effect on mortality.
Given this background, we examined the association between EADs and all-cause mortality in a nationwide Danish cohort of patients with AIH. Our hypothesis was that the mortality is higher in AIH patients with EADs compared with those without and that the presence of multiple EADs will increase the mortality further.
Liver International. 2022;42(11):2466-2472. © 2022 Blackwell Publishing