The change of the quantitative HBsAg level during the natural course of chronic hepatitis B

Background There is insufficient information about HBsAg levels and their correlation with serum hepatitis B virus (HBV) DNA in chronic hepatitis B (CHB). Aims We aimed to describe HBsAg levels during various phases of CHB and to investigate the correlation with serum HBV DNA levels. Methods A total of 645 treatment-naive Korean CHB patients were included in this retrospective cross-sectional study. They were categorized into immune tolerance (IT, n=56), HBeAg-positive hepatitis (EPH, n=150), inactive carrier (IC, n=274) and HBeAg-negative hepatitis (ENH, n=165). The baseline HBsAg and HBV DNA levels were measured. Results The mean HBsAg titres (log IU/ml) differed (P < 0.001): IT 4.29, EPH 3.64, IC 2.05 and ENH 3.23. In 645 patients, HBsAg and HBV DNA showed a significant correlation (r=0.693, P < 0.001), and this was also observed in the IT, EPH and IC groups (r=0.664, r=0.541, r=0.505, respectively, all P < 0.001), but not in the ENH group (r=0.093, P=0.321). Age had a negative correlation with HBsAg (r=-0.451, P < 0.001). The cirrhotic patients had a significantly lower HBsAg level than the non-cirrhotic patients (2.41 +/- 1.36 vs. 3.02 +/- 1.21 log IU/ml, P < 0.001). Conclusions The HBsAg level varied significantly in different phases of CHB and was correlated with HBV DNA during the IT, EPH and IC phases. These findings can provide additional information to understand the natural course and pathogenesis of CHB.