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

backgroundPatients 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.

methodsThe 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.

resultsThe 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.

conclusionPatients 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.