Bacterial infection–triggered HBV-related Acute-on-Chronic Liver Failure is associated with poor prognosis

Bacterial infection (BI) is an important precipitating event in hepatitis B virus (HBV)-related acute-on-chronic liver failure (ACLF) and is associated with systemic inflammation and adverse outcomes. This study aimed to characterize the clinical features and prognostic significance of BI-triggered HBV-related ACLF and to evaluate longitudinal biochemical changes following artificial liver support (ALS) therapy. This retrospective observational study included 118 consecutive patients with HBV-related ACLF who received ALS therapy between January 2017 and December 2025. Patients were categorized into BI-triggered and non-BI-triggered groups according to the identified precipitating event and its temporal relationship with ACLF onset. Clinical characteristics, laboratory parameters, and survival outcomes were compared between groups. Kaplan–Meier analysis and Cox proportional hazards regression were performed to evaluate prognostic factors. Inverse probability of treatment weighting (IPTW) was additionally performed as a sensitivity analysis. Longitudinal changes in biochemical parameters following ALS treatment were also evaluated. Among 118 patients with HBV-related ACLF, 27 (22.9%) had BI-triggered ACLF, with pneumonia being the most common infection type. Compared with the non-BI-triggered group, patients with BI-triggered ACLF had significantly higher white blood cell counts, neutrophil counts, and C-reactive protein levels (all P < 0.05) and poorer survival (log-rank P = 0.009). In multivariable Cox regression, BI-triggered ACLF remained independently associated with mortality after adjustment for MELD score (HR = 1.990, 95% CI: 1.068–3.706, P = 0.030), while MELD score was also independently associated with mortality (HR = 1.077, 95% CI: 1.036–1.120, P < 0.001). Following ALS treatment, decreases in bilirubin levels and partial improvement in coagulation parameters were observed in both groups. BI-triggered HBV-related ACLF was associated with poorer survival and remained independently associated with mortality after adjustment for MELD score. Biochemical improvements were observed following ALS treatment, although their causal relationship with ALS cannot be established from this observational study.