BackgroundPrevious studies have revealed that quantitative hepatitis B surface antigen (HBsAg) or hepatitis B core antibody (qAnti-HBc) levels can be used as predictors of treatment response in both interferon-α and nucleoside analogue therapies. Few data have been published regarding the relationship between quantitative HBsAg or Anti-HBc levels and liver fibrosis stages in patients with chronic hepatitis B (CHB). MethodsWe conducted a cross-sectional study of treatment-naïve CHB patients. A total of 624 CHB patients were recruited. We assessed the serum HBsAg and qAnti-HBc levels, HBV DNA levels, HBV genotypes, BCP/PC mutations, histological fibrosis staging by Scheuer classification. ResultsIn HBeAg (+) patients, the S0-1 subjects had significantly higher serum HBsAg and lower qAnti-HBc levels than the S2-4 subjects (both p < 0.001). A moderate inverse correlation was present between serum HBsAg levels and fibrosis scores (r = −0.381, p < 0.001), and a moderate positive correlation was found between qAnti-HBc levels and fibrosis scores (r = 0.408, p < 0.001). In the HBeAg (−) patients, the S0-1 subjects also had significantly lower qAnti-HBc levels than the S2-4 subjects (p < 0.001); however, no significant difference in the HBsAg levels was observed between the S0-1 and S2-4 subjects (p > 0.05). Serum qAnti-HBc levels showed a moderate positive correlation with fibrosis scores (r = 0.383, p < 0.001), while serum HBsAg levels exhibited a low inverse correlation with fibrosis scores (r = −0.171, p < 0.001). Multiple logistic regression analysis showed that the parameters for predicting significant fibrosis (S ≥ 2) included age, PLT, qAnti-HBc levels, HBV genotype and BCP/PC mutations in HBeAg (+) group, and age, PLT, qAnti-HBc levels in HBeAg (−) group (all p < 0.05). The AUC of qAnti-HBc levels associated with the diagnosis of significant fibrosis abnormalities in HBeAg (+) and HBeAg (−) patients were 0.734 (95%CI 0.689 to 0.778) and 0.707 (95%CI 0.612 to 0.801), respectively. ConclusionOur study found an association between high serum qAnti-HBc levels and significant fibrosis in both HBeAg (+) and HBeAg (−) treatment-naïve CHB patients. However, low serum HBsAg levels were correlated with moderate to severe fibrosis in HBeAg (+) subjects only.