Association of a single nucleotide polymorphism near the interleukin-28B gene with response to hepatitis C therapy in Asian patients

Background and Aims: A single nucleotide polymorphism near the interleukin‐28B (IL28B) gene has been shown to predict hepatitis C virus (HCV) treatment response. We aim to determine the role of the IL28B genotype in Asian patients. Methods: A total of 118 patients (all Korean, 55 patients with genotype 1 infection and 63 patients with genotype 2 infection) were consecutively enrolled and analyzed. Results: The sustained virological response (SVR) rate was 74% (87/118), while 26 patients (22%) relapsed and five patients were non‐responders (4%). For rs8099917, the frequencies of major homozygotes (TT), heterozygotes (GT), and minor homozygotes (GG) were 0.85, 0.14 and 0.01, respectively. Of the 55 patients with HCV genotype 1 infection, the SVR rate was 67% and 44% (P = 0.19) and the non‐response rate was 2% and 22% (P = 0.015) for the major allele and minor or hetero allele, respectively. Of the 63 patients with HCV genotype 2 infection, the SVR rate was 80% and 100% (P = 0.13) and the non‐response rate was 4% and 0% (P = 0.55) for major allele and hetero allele, respectively. Conclusions: The IL28B genotype may help identify non‐responding patients in HCV genotype 1, but not in HCV genotype 2. Because of the high frequency of favorable alleles and the low frequency of non‐response, the IL28B polymorphism may play a smaller role in Asian patients.