The Single Nucleotide Polymorphism In The Promoter Region Of Interferon-γGene Influences The Response To The Treatment Of Interferon-γin Patients With Chronic Hepatitis C Virus Infection

Objective: To investigate the distributing differences between the patients infected withhepatitis C virus (HCV) and the healthy controls, and study the possible association between thegenotypes of the single nucleotide polymorphism (SNP) loci in the interferon–γ(IFN-γ) geneand the results of interferon anti-virus therapy in the patients infected with HCV. We aimed toexamine the SNP of -179(G/T) in the promoter region of IFN-γgene. The SNP might be themarker of predicting the efficacy of IFN-based therapies in patients with chronic hepatitis C.Methods: Using genomic DNA as templates, the single nucleotide polymorphism of -179 lociin the promoter region of IFN-γgene was examined by polymerase chain reaction-restrictionfragment length polymorphism (PCR-RFLP) in 187 patients with chronic HCV infection and100 patients with health controls. The genotypes of -179 loci were compared between thepatients who obtained sustained viral response and those with no sustained viral responseobtained or relapse. All the patients infected with chronic hepatitis C virus who received eitherIFN-γor PEG-IFN-γcombining with ribavirin(RBV) therapy were tested for the biochemicalmarkers of liver and HCV-RNA in the 4th, 8th, 12th, 24th, 48th week during antiviral therapyand in the following 24 weeks after the treatment ceased. Preliminary evaluate the associationbetween the genotypes of -179 loci in the promoter region of IFN-γgene polymorphism withhepatitis C virus infection consequence. Chi-square test was used for statistical.Results: Genotype TT, GG, GT in loci -179 in the promoter region of IFN-γgene were foundin both the patients infected with chronic hepatitis C virus group and the health control group.The genotypes distribution of IFN-γgene -179 loci between the two groups was no significantdifference. The -179 GG genotype and GT genotype in IFN-γgene promoter region were onlyfound in the chronic hepatitis C patients who had completed the standard treatment andfollowing. The SVR rate between the -179 GT genotype and GG genotype in promoter region ofthe IFN-γgene has no significant difference (P=0.744).Conclusion: There is no significant difference between the genotypes in loci -179 in the promoter region of IFN-γgene and the susceptibility of hepatitis C. The virologic respond to theIFN anti-virus treatment between the patients with -179 GT genotypes in promoter region ofIFN-γgene and those with GG genotype has no significant difference. Thus, the SNP at -179 locimay not predict therapeutic efficiency of interferon-γin the patients with chronic hepatitis Cvirus infection.