Predictors of survival in autoimmune liver disease overlap syndromes

Abstract

Background: Survival in patients with autoimmune liver disease overlap syndromes (AILDOS) compared to those with single autoimmune liver disease is unclear.

Aim: To investigate the survival of patients with AILDOS and assess the accuracy of non-invasive serum models for predicting liver-related death.

Methods: Patients with AILDOS were defined as either autoimmune hepatitis and primary biliary cholangitis overlap (AIH-PBC) or autoimmune hepatitis and primary sclerosing cholangitis overlap (AIH-PSC) and were identified from three tertiary centres for this cohort study. Liver-related death or transplantation (liver-related mortality) was determined using a population-based data linkage system. Prognostic scores for liver-related death were compared for accuracy [including liver outcome score (LOS), Hepascore, Mayo Score, model for end-stage liver disease (MELD) score and MELD incorporated with serum sodium (MELD-Na) score].

Results: Twenty-two AILDOS patients were followed for a median of 3.1 years (range, 0.35-7.7). Fourteen were female, the median age was 46.7 years (range, 17.8 to 82.1) and median Hepascore was 1 (range, 0.07-1). At five years post enrolment, 57% of patients remained free from liver-related mortality (74% AIH-PBC, 27% AIH-PSC). There was no significant difference in survival between AIH-PBC and AIH-PSC. LOS was a significant predictor of liver-related mortality (P < 0.05) in patients with AIH-PBC (n = 14) but not AIH-PSC (n = 8). A LOS cut-point of 6 discriminated liver-related mortality in AIH-PBC patients (P = 0.012, log-rank test, 100% sensitivity, 77.8% specificity) (Harrell's C-statistic 0.867). The MELD score, MELD-Na score and Mayo Score were not predictive of liver-related mortality in any group.

Conclusion: Survival in the rare, AILDOS is unclear. The current study supports the LOS as a predictor of liver-related mortality in AIH-PBC patients. Further trials investigating predictors of survival in AILDOS are required.

Keywords: Autoimmune hepatitis; Autoimmune liver disease overlap syndromes; Hepascore; Liver outcome score; Liver-related death; Primary biliary cholangitis; Primary sclerosing cholangitis.

Figure 1

Kaplan-Meier survival curves for 5-year liver-related mortality with number of patients at risk listed underneath. A: All autoimmune liver disease overlap syndromes patients; B: Autoimmune hepatitis and primary biliary cholangitis overlap patients and autoimmune hepatitis and primary sclerosing cholangitis overlap patients compared using the log-rank test. AILDOS: All autoimmune liver disease overlap syndromes; AIH-PBC: Autoimmune hepatitis and primary biliary cholangitis overlap; AIH-PSC: Autoimmune hepatitis and primary sclerosing cholangitis overlap.

Figure 2

Kaplan-Meier survival curves for 5-year liver-related mortality according to liver outcome score compared using the log-rank test with number of patients at risk listed underneath. A: All autoimmune liver disease overlap syndromes patients; B: Autoimmune hepatitis and primary biliary cholangitis overlap patients; C: Autoimmune hepatitis and primary sclerosing cholangitis overlap patients. LOS: Liver outcome score; AILDOS: All autoimmune liver disease overlap syndromes; AIH-PBC: Autoimmune hepatitis and primary biliary cholangitis overlap; AIH-PSC: Autoimmune hepatitis and primary sclerosing cholangitis overlap.