Association Between Indirect Bilirubin Percentage to Albumin Ratio and Outcome of Hepatitis B Related Acute on Chronic Liver Failure Treated With Artificial Liver Support System

This study investigates the impact of the indirect bilirubin percentage-to-albumin ratio (iBAR) on the prognosis of patients with acute-on-chronic liver failure (ACLF), as defined by the Chinese Group on the Study of Severe Hepatitis B-ACLF (COSSH ACLF) criteria, who were treated with an artificial liver support system (ALSS). In a retrospective cohort of 258 eligible patients, restricted cubic splines, linear regression, and Cox proportional hazards models were used to analyse the association of iBAR with disease severity and 28-day and 90-day outcomes. The 28-day transplant-free and overall survival rates were 76.4% and 82.2%, respectively, while the 90-day rates were 58.5% and 66.3%. The iBAR was significantly lower in 28-day transplant-free survivors compared to those who underwent transplantation or died (6.47 ± 2.95 vs. 8.87 ± 2.49, p < 0.001), with similar findings for 90-day outcomes (6.09 ± 2.75 vs. 8.38 ± 2.88, p < 0.001). A positive association was observed between iBAR and COSSH ACLF score (adjusted β = 0.14, 95% CI: 0.11-0.18, p < 0.001). Furthermore, iBAR was independently associated with higher risks of 28-day transplant-free mortality (adjusted HR = 1.21, 95% CI: 1.10-1.34, p < 0.001), 28-day overall mortality (adjusted HR = 1.26, 95% CI: 1.12-1.42, p < 0.001), 90-day transplant-free mortality (adjusted HR = 1.13, 95% CI: 1.06-1.22, p < 0.001), and 90-day overall mortality (adjusted HR = 1.14, 95% CI: 1.05-1.23, p = 0.002). Patients with an iBAR > 6.13 had significantly poorer 28-day and 90-day prognoses compared to those with iBAR ≤ 6.13 (all adjusted HR > 1, p < 0.05). In conclusion, iBAR is positively associated with disease severity and adverse prognosis in COSSH ACLF patients receiving ALSS therapy, suggesting its potential as a prognostic biomarker that warrants validation in future prospective, multicenter studies.