Mutational analysis of various sub genomic regions of HCV and their role in interferon therapy response

Abstract

Combination therapy with interferon (IFN) and ribavirin for 24 to 48 weeks is the current standard treatment for chronic hepatitis C. Success rate is 67-80%. There are four subgenomic regions of HCV in which distinct mutations have been observed in response to IFN therapy; E2-PePHD, NS5A- ISDR, NS5A-PKRBD and NS5A-V3 domains. Current meta analysis gives comprehensive details of mutations in subgenomic regions and their role in non responsiveness to IFN treatment. It has been observed that E2-PePHD region is well conserved region and show high sensitivity to IFN-ribavirin tiherapy. The substitutions within the NS5A-ISDR to the treatment outcome are conflicting. Mutations within the NS5A-PKRBD of HCV type 1 are associated with a long-term sustained response to IFN-ribavirin therapy. There is a considerable association between efficacy of treatment and a high mutation rate within NS5A-V3 domain has been observed. There are also other domains of HCV i.e. IRRDR, CRS and NLS, but no significant mutations been studied in these regions, more research is to be required.