Abstract: AIM: To observe the effect of entecavir (ETV) and adefovir dipivoxil (ADV)on suppressing for the function of regulatory T cells (Treg) for patients with chronic hepatitis B(CHB). METHODS: Thirty six CHB patients were randomly divided into the ETV and ADV groups. Patients in ETV group were administrated ETV 0.5 mg q.d., whereas the ones in the ADV group were dosed with ADV 10 mg q.d.. All the subjects were treated for 48 weeks and were followed at the end of the 12th, 24th, 36th and 48th week to collect the peripheral blood for test. Flow cytometry was applied to test the percentage of Treg, whose cytokines including IL-10 and TGF-β₁ were detected by ELISA. Real time PCR was used to test the quantities of HBV DNA as well as the Foxp3 mRNA. Besides, the liver function including ALT and T-Bil were also examined for all the CHB patients. RESULTS: There was no statistical difference between the two groups before therapy. The percentages of Treg in ETV group were significantly lower than those of ADV group at the end of the 24th, 36th and 48th week. The levels of Treg's functional factors, the Foxp3, IL-10 and TGF-β₁, were also totally lower in the ETV group when compared with the ADV group (P<0.05). For the function of anti-HBV, the HBV DNA copies in ETV group were significantly lower than those in ADV group at the end of the 12th and 36th week (P<0.05). The level of ALT was also significantly lower in ETV group at the end of the 12th week when compared with the ADV group (P<0.05). But there was no statistical difference of T-Bil level between any point times of follow-up. Pearson analysis showed that percentages of Treg correlated the copies of HBV-DNA positively(r=0.785 and P=0.016). CONCLUSION: Entecavir is proven to be more effective on suppressing for the function of regulatory T cells for patients with CHB when compared with adefovir dipivoxil.

Key words: Hepatitis B, Entecavir, Adefovir dipivoxil, Regulatory T cells, Cytokines