Metabolic Dysfunction-Associated Steatotic Liver Disease Facilitates Hepatitis B Surface Antigen Seroclearance and Seroconversion.

BACKGROUND & AIMS: Hepatitis B surface antigen (HBsAg) seroclearance is the goal of functional cure for hepatitis B virus (HBV) infection. However, the impact of metabolic dysfunction-associated steatotic liver disease (MASLD) on this favorable outcome remains unclear. METHODS: Patients with chronic hepatitis B (CHB) were consecutively recruited. MASLD was defined by the newly proposed disease criteria. Cumulative incidences and associated factors of HBsAg seroclearance/seroconversion were compared between the MASLD and non-MASLD groups. RESULTS: From 2006 to 2021, 4084 treatment-naive hepatitis B e antigen (HBeAg)-negative CHB patients were included. At baseline, CHB patients with concurrent MASLD (n = 887) had significantly lower levels of HBsAg and HBV DNA than the non-MASLD group (n = 3197). During a median follow-up of 5.0 years, MASLD was associated with a higher likelihood of HBsAg seroclearance (adjusted hazard ratio [aHR], 1.43; 95% confidence interval [CI], 1.10-1.85; P = .007), and the accumulation of individual metabolic dysfunctions additively facilitated HBsAg seroclearance. In addition, a higher rate of HBsAg seroconversion was observed in patients with MASLD versus those without MASLD (aHR, 1.37; 95% CI, 1.00-1.86; P = .049). In sensitivity analysis, patients with intermittent MASLD had an intermediate probability of HBsAg seroclearance. After balancing clinical and virologic profiles by inverse probability of treatment weighting (IPTW), MASLD was still associated with a higher HBsAg seroclearance rate (IPTW-adjusted HR, 1.41; 95% CI, 1.09-1.84; P = .010). CONCLUSIONS: In untreated HBeAg-negative CHB patients, concurrent MASLD is associated with higher rates of HBsAg seroclearance and seroconversion. Metabolic dysfunctions have additive effects on the functional cure of CHB.