Quantitative Hepatitis B Surface Antigen Titres in Chinese Chronic Hepatitis B Patients over 4 Years of Entecavir Treatment

Abstract

Background

The clinical value of quantitative hepatitis B surface antigen (qHBsAg) titre in patients taking nucleotide/nucleoside analogues (NAs) is still controversial. This study aims to investigate the dynamic changes of qHB-sAg titres and their significance for predicting virological response (VR) and serological response (SR) to long-term entecavir (ETV) treatment.

Methods

A total of 48 ETV-naive patients were enrolled and followed prospectively for 4 years, 32 of whom were hepatitis B e antigen (HBeAg)-positive at baseline. Serum alanine aminotransferase (ALT), qualitative HBV serological markers and HBV DNA were detected; qHBsAg titres were measured using Elecsys® HBsAg II Quant Assay (Roche Diagnostics, Penzberg, Germany).

Results

The mean baseline HBV DNA and qHBsAg were 7.51 log₁₀ copies/ml and 3.78 log₁₀ IU/ml, respectively. After 48 months of ETV treatment, the rates of VR (<291 copies/ml), ALT normalization and SR (HBeAg/antibody to HBeAg [anti-HBe]) were 89.6% (43/48), 89.6% (43/48) and 34.4% (11/32), respectively. There was a decrease in qHBsAg titres from baseline to month 48, ranging from 3.78 to 3.10 log₁₀ IU/ml. The greatest decrease of qHBsAg was observed in the first 3 months of treatment (0.47 log₁₀ IU/ml), which was significantly correlated with corresponding HBV DNA decreases (3.89 log₁₀ copies/ml; P=0.032). By using receiver operating characteristic (ROC) curve analysis, qHBsAg titres at baseline (area under the curve [AUROC]=0.647) and 3 months after treatment (AUROC=0.586) had poor power in predicting 48-month VR; qHBsAg titres at baseline (AUROC=0.779) and 3 months after ETV treatment (AUROC=0.658) had poor power in predicting 48-month SR in patients who were HBeAg-positive at baseline. Additionally, the decrease of qHBsAg in the first 3 months of treatment also had poor power in predicting either 48 month VR or SR.

Conclusions

ETV is efficacious in NA-naive patients, and qHBsAg titres decreased significantly in the first 3 months of ETV treatment. However, qHBsAg titre was not a good predictor of 4-year VR and HBeAg/anti-HBe SR in this cohort.