Serum O-glycosylated HBsAg levels correlate with HBV RNA in HBeAg positive CHB patients during antiviral therapy

Recent evidence has indicated that the O-glycosylated PreS2 domain of the middle HBsAg is a distinguishing characteristic that allows the identification of HBsAg of HBV Dane particles and SVPs. This study's objective was to assess the changes in serum O-glycosylated HBsAg levels in CHB patients undergoing ETV or Peg-IFNα treatment. Our retrospective study enrolled 86 patients with genotype C CHB. We determined the O-glycosylated HBsAg, HBsAg, HBeAg, HBV DNA, and HBV RNA at baseline and during ETV or Peg-IFNα treatment. The correlations between O-glycosylated HBsAg and conventional HBV marker levels were also examined. Furthermore, we performed a ROC analysis to evaluate the predictive value of individual biomarkers for virological response. At baseline, the serum O-glycosylated HBsAg levels were significantly correlated with the HBsAg (r = 0.754), HBV DNA (r = 0.498), HBeAg (r = 0.404), and HBV RNA (r = 0.399) in HBeAg positive patients. O-glycosylated HBsAg decreased after antiviral therapy. Both O-glycosylated HBsAg and HBsAg were significantly correlated with serum HBV DNA as well as HBV RNA at baseline, while only O-glycosylated HBsAg still correlated with HBV RNA (r = 0.397) in DNA-undetectable patients after ETV therapy. O-glycosylated HBsAg was significantly correlated with HBV RNA (r = 0.846) in DNA-undetectable patients after Peg-IFNα therapy compared to that of HBsAg (r = 0.800). Serum O-glycosylated HBsAg level decreased during anti-viral therapy and correlated well with conventional HBV markers in HBeAg positive genotype C patients, suggesting that it could be a potential monitoring biomarker in HBV DNA-suppressed patients. •There was a strong baseline correlation between serum O-glycosylated HBsAg levels and traditional HBV markers in HBeAg positive patients.•For patients with undetectable HBV DNA post-therapy, serum O-glycosylated HBsAg more accurately reflects HBV RNA levels.•Serum O-glycosylated HBsAg levels decreased more in the IFN group than the ETV group in HBeAg positive patients.•Serum O-glycosylated HBsAg could serve as a novel predictor of antiviral responses in patients with CHB genotype C.