Objective: To evaluate the effects of antiviral agents on intrahepatic HBV covalently closed circular DNA (cccDNA) in HBeAg-positive chronic hepatitis B patients.
Methods: Seventy-one HBeAg positive chronic hepatitis B patients were enrolled in this study. Lamivudine was administered to 35 patients for 48 weeks, sequential therapy with lamivudine-IFN alpha-2b to 24 of the 71 patients for 48 weeks, and interferon alpha (IFN alpha-2b) was administered to 12 for 24 weeks. All subjects were followed-up for 24 weeks. Serum HBV DNA, intrahepatic HBV DNA and cccDNA were measured quantitatively by PCR. HBV genotypes were analyzed by PCR-RFLP.
Results: Forty-eight weeks of sequential lamivudine-IFN alpha-therapy and lamivudine monotherapy and 24 weeks of IFN alpha monotherapy reduced the intrahepatic HBV DNA to (4.7+/-1.1) log10, (4.6+/-1.5) log10 and (5.6+/-1.5) log10, and cccDNA to (3.4+/-1.3) log10, (3.8+/-1.1) log10 and (5.0+/-1.5) log10, significantly lower than therapy (P < 0.05). Seventeen of the 71 patients developed HBeAg seroconversion, and the reduction of cccDNA in the HBeAg seroconverted patients was significantly more than that of the HBeAg positive patients (P < 0.05). After 24 weeks of antiviral therapy withdrawal, 18 patients achieved sustained virological response, and the baseline intrahepatic cccDNA in the patients with sustained virological response was significantly lower than that of patients with virological rebound (P < 0.05). The change in intrahepatic cccDNA correlated positively with the reduction in intrahepatic HBV DNA (P < 0.05). The cccDNA levels correlated with the serum HBeAg titers at the end of the treatment (P < 0.01). Of the total 71 cases, HBV genotype C accounted for 85.9% (n = 61), and genotype B for 14.1% (n = 10). There was no significant difference in the changes of intrahepatic HBV DNA and cccDNA levels between HBV genotypes C and B (P >0.05).
Conclusions: Both 48 weeks of sequential lamivudine-IFN alpha and lamivudine monotherapy strongly reduced intrahepatic HBV DNA and cccDNA more than 24 weeks of IFN alpha monotherapy. Low baseline intrahepatic cccDNA levels might predict a good long-term efficacy of antiviral treatment. The reduction of intrahepatic cccDNA correlated positively with the changes of intrahepatic HBV DNA, and intrahepatic cccDNA levels correlated with serum HBeAg titers. HBV genotypes had no obvious influence on intrahepatic HBV DNA load or cccDNA load.