Objective To investigate the dynamic change of hepatitis B virus quasispecies within complete genome during the early stage of IFN-α treatment and its impact on virological response.
Methods Sixteen patients with chronic hepatitis B receiving IFN-α treatment were investigated. HBV DNA was extracted from serum sample at baseline and week 12. The complete genome of HBV was amplified, then cloned and sequenced. The quasispecies heterogeneity of HBV complete genome was depicted at baseline and week 12.
Results The quasispecies heterogeneity of the genome except for C-ORF were comparable in three groups at baseline and week 12. The quasispecies diversity at amino acid levels of responders within C-ORF were higher than that of non-responders at baseline. The quasispecies diversity within the C-ORF of partial responders was reduced in the early stage of IFN-α treatment. Furthermore, the mean genetic distance at amino acid levels of partial responders was significantly higher than that of the non-responders at week 12. The evolutionary rate was not different between non-responders and partial responders.
Conclusions In the immune clearance phase, the patients who had greater viral quasispecies diversity within C-ORF at amino acid level had more chance to obtain the early virological response during IFN-α treatment.