Polymorphism near the IL28B gene in Korean hepatitis C virus-infected patients treated with peg-interferon plus ribavirin

Background: Single nucleotide polymorphisms (SNPs) near the IL28B gene have recently been described as predictors of antiviral therapy responses in patients with hepatitis C virus (HCV) genotype-1. Objectives: The aim of this study was to investigate the association between genetic variation near the IL28B gene and treatment outcome prediction in Korean patients receiving peg-interferon (PEG-IFN) plus ribavirin therapy. Study design: The allelic discrimination assay by Taqman real-time PCR was developed to determine genotypes of SNPs, rs12979860 and rs8099917, which were analyzed in 65 Korean patients with HCV genotype-1. Results: For rs12979860, the frequency of patients with sustained virological response (SVR) was 70.2% in those with the CC genotype and 25% in those with the CT genotype. Early virological response (EVR) in patients with the CC genotype (84.2%) was higher than in those with the CT genotype (25.0%). For rs8099917, patients with the TT genotype showed significantly higher in SVR and EVR than those with the TG/GG genotype (69.6% vs 33.3% and 82.1% vs 44.4%, respectively). With regards to the genotype frequency of the SNPs, the homozygous genotypes for rs12979860 (CC) or rs8099917 (TT) in Korean patients showed a significantly higher frequency as compared with other ethnicities; Caucasians, African-American, Hispanic, and Japanese. Conclusions: These results demonstrate that the genotypes rs12979860 CC and rs8099917 TT were more frequently observed in Korean patients compared to other ethnicities, and suggest that the genetic characteristics of patients may be prognostic factor that predicts antiviral response to PEG-IFN therapy for chronic hepatitis C.