Hepatitis B genotypes and the response to interferon therapy

Background/Aims: Possible pathogenic differences among hepatitis B virus (H BV) genotypes have been observed; however, the response to interferon thera py among HBV genotypes remains unknown. We therefore analyzed the efficacy of interferon alfa in the treatment of chronic hepatitis B patients with di fferent HBV genotypes, Methods: Fifty-eight genotype B or C infected chronic hepatitis B patients who had been treated with interferon alfa-2b were retrospectively studied. The response to interferon was defined as normalization of serum aminotrans ferase level, loss of hepatitis B e antigen and HBV DNA 48 weeks post-treat ment, Results: Baseline data of both groups of patients were comparable; however, genotype C patients had a higher serum aminotransferase level and a higher frequency of core promoter mutation, The response rate was 41% and 15% in genotype B and C patients, respectively (p=0.045), In those with higher ser um aminotransferase levels, the response rate was 50% and 17%, respectively (p=0.025). Additionally, younger age and genotype B infection may predict a better response to interferon alfa, Conclusions: HBV genotype C, compared to genotype B, is associated with a h igher frequency of core promoter mutation, and a lower response rate to int erferon alfa therapy.