Mutation in the NS5A Region of Chinese HCV-1b Isolates and Its Correlation with Efficacy of Interferon Alpha Therapy

Objective\ To study the correlation between mutations in the NS5A region of hepatitis C virus genotype 1b and the efficacy of interferon alpha (IFN α) therapy. Methods\ Twenty patients with chronic HCV 1b infection, including 10 responders and 10 non responders to standard IFN α therapy, were investigated. HCV 1b NS5A 2209 2248 region was amplified by RT PCR and the second round product was directly sequenced before treatment. Results\ In IFN α response group, 4 out of 10 HCV isolates (40%) had mutations of amino acid in NS5A 2209 2248 region, which were all intermediate types; while in IFN α non response group, none of HCV isolates (0/10,0%) had mutations, which were all wild types (P<0.05). There was no mutant type isolates in these two groups. All patients (4/4,100%) infected with intermediate type and 6 out of 16 patients(37.5%) infected with wild type of HCV 1b were responsive to IFN α therapy (P<0.05). Conclusion\ The sequences in NS5A 2209 2248 region of Chinese HCV 1b isolates were relatively conservative. There may be a correlation between the efficacy of IFN α therapy and the mutations of amino acid in NS5A 2209 2248 region of Chinese HCV 1b isolates.