Pegylated interferon α-2a(Peg-IFN-α) not only inhibit viral replication, but also play an important role in immune regulation, while Nucleoside analog(ue) drugs only inhibit viral replication. In hepatitis B infection, CD8+T cells are the main effector cells in adaptive immune response. This study was aimed at investigating the changes of CD8+T cells frequency and function, and the expression of costimulatory molecules during Peg-IFN-αand nucleoside analog(ue) therapy.Meanwhile, the investigators want to verify whether Peg-IFN-α suppressed the virus and the reduction of virus led to the recovery of CD8+T cells function, or Peg IFN - alpha enhanced CD8+T cells function which gave rise to the decline of the virus.

Pegylated interferon α-2a(Peg-IFN-α)and Nucleoside analog(ue) drugs can inhibit viral replication , but Peg-IFN-α also play an important role in immune regulation. In hepatitis B infection, CD8+T cells are the main effector cells in adaptive immune response.Peg-IFN-α recommended as the first-line treatment has a higher chance to achieve HBeAg seroconversion and even HBsAg disappearance than nucleoside analog(ue) drugs, which may be related to the functional activation of CD8+T cells in the case of hepatitis and the function enhancement of CD8+T cells during Peg-IFN-α therapy. This study was aimed at investigating the changes of CD8+T cells frequency and function, and the expression of costimulatory molecules during Peg-IFN-αand nucleoside analog(ue) therapy.Meanwhile, the investigators want to explore whether the decline of HBsAg and HBeAg resulted in recovery of CD8+T cells function, or recovery of CD8+T cells function led to the decrease of HBsAg and HBeAg. Several studies demonstrated that HBsAg and HBeAg could damage CD8+T cells function, and the loss of HBsAg and HBeAg led to recovery of CD8+T cells function.

Inclusion Criteria:

• HBsAg and HBeAg positive for more than 6 months, HBV DNA detectable with ALT level abnormal lasted for three months and at least time190 IU/L or liver puncture biopsy demonstrated apparent inflammation, never treated before enrolled.

Exclusion Criteria:

• Active consumption of alcohol and/or drugs
• Co-infection with human immunodeficiency virus, hepatitis C virus, or hepatitis D virus
• History of autoimmune hepatitis
• Psychiatric disease
• Evidence of neoplastic diseases of the liver