The clinical characteristics, pre- and post-liver transplantation outcomes in patients having autoimmune overlap syndromes

The differences in post-liver transplant outcomes of patients with autoimmune hepatitis who present with overlapping autoimmune liver diseases

BACKGROUND

Patients with autoimmune hepatitis (AIH) may co-present with features of primary biliary cholangitis (PBC) or primary sclerosing cholangitis (PSC). Using a national transplant registry, the outcomes of patients with these autoimmune liver conditions were compared.

METHODS

The UNOS-STAR registry was used to select a study population of AIH, PSC, and PBC liver transplant (LT) patients. Living and multi-organ transplant cases were excluded. Using the UNOS-registered diagnoses, the study population was subdivided into those with nonoverlapping autoimmune liver diseases and those with overlapping forms (e.g., AIH-PBC). Outcomes were compared, using endpoints such as all-cause mortality, graft failure, and organ-system specific causes of death.

RESULTS

The main analysis featured 2048 entries, with 1927 entries having nonoverlapping AIH, 52 entries having PSC overlap, and 69 entries having PBC overlap. Patients with PBC overlap were more likely to have graft failure (adjusted hazard ratio [aHR] 3.46 95% CI 1.70-7.05), mortality secondary to respiratory causes (aHR 3.57 95% CI 1.23-10.43), and mortality secondary to recurrent disease (aHR 9.53 95% CI 1.85-49.09). Case incidence rates reflected these findings, expressed in events per 1000 person-years. For patients with PBC overlap and nonoverlapping AIH cases, respectively. Graft failure: 28.87 events vs. 9.42 events, mortality secondary to respiratory causes: 12.83 deaths vs. 3.77 deaths, mortality secondary to recurrent disease: 6.42 deaths vs. 1.26 deaths. Those with AIH-PSC overlap experienced a higher risk of death from graft infection (aHR 10.43 95% CI 1.08-100.37; case-incidence rate: 3.89 vs. 0.31 mortalities per 1000 person-years). Supplementary analysis showed similar findings, in which overlapping autoimmune conditions were associated with higher adverse outcome rates.

CONCLUSION

Patients with AIH-PBC overlap have higher risk of mortality due to recurrent liver disease and respiratory causes, and patients with AIH-PSC overlap have higher risk of mortality due to graft infection. While further prospective studies are needed to clarify the underlying mechanisms related to these findings, our study characterizes the prognostic implications of AIH overlap on post-LT mortality and graft failure risks.

Gender and Autoimmune Liver Diseases: Relevant Aspects in Clinical Practice

Autoimmune liver diseases (AILDs) include autoimmune hepatitis, primary biliary cholangitis and primary sclerosing cholangitis. The etiologies of AILD are not well understood but appear to involve a combination of genetic and environmental factors. AILDs commonly affect young individuals and are characterized by a highly variable clinical course. These diseases significantly influence quality of life and can progress toward liver decompensation or the onset of hepatocellular or cholangiocarcinoma; a significant number of patients eventually progress to end-stage liver disease, requiring liver transplantation. In this review, we focus on the sex characteristics and peculiarities of AILD patients and highlight the relevance of a sex-specific analysis in future studies. Understanding the sex differences underlying AILD immune dysregulation may be critical for developing more effective treatments.