Quantitative HBsAg as a biomarker for disease staging in untreated chronic hepatitis B patients: a cross-sectional study

The study examined the use of quantitative HBsAg (hepatitis B surface antigen) as a biomarker to distinguish different phases of chronic HBV infection in 90 HBeAg-negative treatment-naïve patients. The median viral load was 328.5 IU/mL and median HBsAg was 213.5 IU/mL. A strong positive correlation was found between HBsAg and HBV DNA (r = 0.721). HBsAg showed a weak but statistically significant association with liver fibrosis. Quantitative HBsAg was excellent at distinguishing between low and high replicative phases (AUC = 0.819) with an optimal threshold of 450 IU/mL (sensitivity 81.3%, specificity 77.6%). In multivariate analysis, HBV DNA and AST were independently associated with disease phase, while qHBsAg was not an independent predictor. Quantitative HBsAg is a relevant tool for better patient stratification and when combined with other markers may contribute to optimized monitoring.