HBcrAg Dynamic Change During Treatment Predicts HBsAg Loss in Pediatric Patients With Chronic Hepatitis B

In children with chronic hepatitis B(CHB), HBsAg loss is a critical indicator of functional cure. However, little is known about the correlation between the kinetics of HBcrAg and HBsAg loss in the pediatric population. The aim of this study was to investigate whether the HBcrAg change in children CHB patients receiving antiviral therapy is associated with the occurrence of HBsAg loss. A prospective cohort study was conducted on 86 pediatric patients with treatment-naive CHB. The speed of HBcrAg change was calculated during the treatment period, and the patients were divided into two groups (rapid decline, slow decline) according to the median speed (0.0221 log₁₀ U/mL/week). The primary outcome is the serological HBsAg loss in CHB children after antiviral therapy. In 86 participants, 26 (30.2%) achieved HBsAg loss at the end of follow-up. Baseline HBsAg levels (HR = 0.36, 95% CI: 0.19-0.68) and the speed of HBcrAg decline during treatment (HR = 1.30, 95% CI: 1.10-1.40) were found to be independent predictors of the occurrence of HBsAg loss. The Kaplan-Meier curve showed that the cumulative incidence of HBsAg loss in the rapid decline group was significantly higher than that in the slow decline group. Also, receiver operating characteristic curve showed that the speed of HBcrAg decline could effectively predict the occurrence of HBsAg loss (AUC: 0.735, p < 0.001). Moreover, when combining the baseline HBsAg levels for prediction, the AUC increased to 78.4%. The speed of HBcrAg decline during antiviral therapy was significantly associated with HBsAg loss in pediatric CHB patients.