Naturally occurring NS5A and NS5B resistant associated substitutions in HCV and HCV/HIV patients in iranian population.

Background: The introduction of direct acting antivirals (DAAs) for hepatitis C virus (HCV) treatment promises shorter treatment duration, higher cure rates and fewer side effects. Naturally, occurring Resistance Associated Substitutions (RASs) are major challenge to the success of the HCV antiviral therapy.

Aim: To determine the naturally occurring NS5A and NS5B RASs in Iranian HCV and HCV/human immunodeficiency virus (HIV) patients.

Methods: A total of 209 DAA-naïve chronic HCV patients including 104 HCV mono-infected and 105 HCV/HIV co-infected cases were enrolled. Amplification and Sanger population sequencing of NS5A and NS5B regions of HCV genome were carried out. The amino acid sequence diversity of the NS5A and NS5B regions were analyzed using geno2pheno HCV.

Results: NS5A RASs were detected in 25.5% of HCV and 16.9% of HCV/HIV subjects. In HCV cases, clinically relevant RASs were L28M followed by M28Vand Q30H and Y93H/N. In HCV/HIV subjects, clinically relevant RASs were Y93H/N followed by L28M and P58T and M28V/T and Q30R. NS5B RASs were observed in 11.8% of HCV and 5.9% of HCV/HIV subjects. Clinically relevant substitutions were included V321A/I, C316Y, S282R and L159F. The major S282T mutation was not observed.

Conclusion: The emergence of RASs is a growing issue in the setting of current treatment with DAAs. Although currently, screening of RASs is recommended before specific DAA regimens, it should be consider in patients with therapeutic failure and in the cases of retreatment.