Unfortunately, the exact molecular mechanism of this ineffectiveness of IFN�� is still unknown. Currently, how to identify and use indicators to predict treatment response till has been widely concerned. In present study, we will evaluate the effectiveness of quantification of serum HBsAg in predicting the response of pegylated interferon ��-2a in HBeAg-positive CHB patients with prior lamivudine exposure, and the findings of this study would provide an important reference for helping CHB patients achieve sustained curative response. Patients and methods Patients HBeAg-positive chronic hepatitis B patients with prior lamivudine exposure and received pegylated interferon alfa-2a for recurring antiviral therapy were screened in this study, all of them were followed up at the Digestion Department of Chengdu Military General Hospital from January 2007 to December 2012.

The inclusion criteria were as follows: adults (18�C70 years), prior lamivudine exposure for more than 1 years, positive HBeAg statue, HBV DNA levels higher than 1.0��10^5 copies/mL, and elevated serum alanine amino-transferase (ALT) value. The exclusion criteria were as follows: ��co-infection with other hepatitis virus or human immunodeficiency virus; ��evidence of other causes of liver disease, such as autoimmune hepatitis and primary biliary cirrhosis; ��evidence of advanced liver diseases, such as decompensated cirrhosis, severe hepatitis, and hepatic carcinoma; ��poor compliance or no availability of detailed laboratory test results.

This study was carried out in accordance with the ethics committee of Chengdu Military General Hospital and informed consent was obtained from each participant. Study design and definition This is a prospective observational study, and all eligible participants were administered pegylated interferon alfa-2a (PegINF��-2a) (Roche Pharmaceuticals, Shanghai, China) at a dose of 180 ��g once a week by subcutaneous injection for 12 months. Quantification of serum HBsAg was carried out at baseline, months 3, 6 and at the end of treatment (12 months), and the quantitative HBV DNA and liver function was also assessed at each time-point. According to the follow-up outcomes in this study, patients were designated as either responders or nonresponders. Responders were defined as an ALT normalization, accompanying with HBeAg seroconversion at the end of treatment and the presence of a sustained virological response. Patients who did not achieve the above-mentioned criteria were defined as NRs. And sustained Batimastat virological response was defined as undetectable serum HBV DNA both at the end of therapy and 6-month of follow-up.