Hepatitis B surface antigen concertration in prediction of response to treatment-naive, hepatitis B e antigen-positive patients receiving entecavir

Abstract

Objective To monitor the dynamic changes of quantitative hepatitis B surface antigen concentrations in HBeAg-positive treatment-naive CHB patients and to investigate its potential role in predicting virological response to entecavir therapy. Methods This was a retrospective study. 26 HBeAg-positive treatment-naive CHB patients receiving ETV (0.5 mg once a day) were consecutively recruited and followed up for 1 year from the Center of Liver diseases of the First Affiliated Hospital of Fujian Medical University between January 2011 and July 2013. Serums samples were collected at baseline and every 3 months (month 3, month 6, month 9 and month 12, respectively). HBsAg and HBeAg concentrations were measured using commercially available chemiluminescence assay. HBV DNA levels were determined by real-time polymerase chain reaction. ALT levels were measured by velocity method. A VR（virological response） was defined as HBV DNA levels decreased to less than 500 IU/ml through 1 year of ETV treatment. The statistical analyses including Student t-test, χ2-test, ROC curve analysis, etc. were performed using statistical analysis software SPSS version 16.0 and GraphPad Prism software version 5.0. Results After 1 year of treatment, 17 patients achieved VR, 9 patients didn't. Baseline characteristics of the patients were as follows: there was no significant difference of ALT levels between the VR+ group and VR- group (141.82±77.29 IU/ml and 134.2±49.76 IU/ml, respectively, t=0.27, P=0.793). HBV DNA levels of VR+ group was signi?cantly lower than that of the VR- group (6.76±1.00 lg IU/ml and 7.65±0.87 lg IU/ml, respectively, t=-2.27, P=0.033). HBsAg concentration of the VR+ group was lower than that of the VR- group, but showed no-statistically significant (3.79±0.61 lg IU/ml and 4.19±0.43 lg IU/ml, respectively, t=-1.75 P=0.094). A rapid decline in HBsAg concentration during the first 3 months of therapy followed by a much slower decline in the subsequent period was observed. From baseline to month 3, the reductions of HBsAg concentration were 0.32±0.29 and 0.14±0.10 lg IU/ml in VR+ and VR- groups (t=2.245, P=0.035), respectively. The lg HBsAg concentration at month 3 showed the biggest area under the curve (AUC) (AUC=0.840, P=0.005). The best cut-off value for the HBsAg concentration at month 3 for the prediction of VR was 3.8650 lg IU/ml, with a diagnostic sensitivity and specificity of 82.4% and 77.8%, respectively. Conclusions HBsAg level less than or equal to 3.8650 lg IU/ml at month 3 of ETV treatment may be a useful parameter in predicting virological response to ETV in HBeAg-positive CHB patients.（Chin J Lab Med，2014,37：96-99） Key words: Hepatitis B chronic; Hepatitis B surface antigen; Hepatitis B e antigen; Guanine