Role of interleukin-28B polymorphisms in the treatment of hepatitis C virus genotype 2 infection in Asian patients

Abstract

Genome-wide association studies have linked single nucleotide polymorphisms (SNPs) near the interleukin-28B gene to the hepatitis C virus genotype 1 (HCV-1) response to peginterferon/ribavirin treatment. We aimed to explore the impact on the treatment outcomes of Asian HCV-2 patients. We determined rs8105790, rs8099917, rs4803219, and rs10853728 to be candidate SNPs in 482 Asian HCV-2 patients treated with the standard of care. Because the first three SNPs were in very strong linkage disequilibrium with one another (r2 = 0.94-0.96), rs8099917 and rs10853728 were selected for an analysis of their influence on the achievement of rapid virological response [RVR; seronegativity for hepatitis C virus (HCV) RNA in treatment week 4] and sustained virological response (SVR; seronegativity for HCV RNA throughout 24 weeks of posttreatment follow-up). The rs10853728 genotype did not predict RVR or SVR in HCV-2 patients. However, patients with the rs8099917 TT genotype, in comparison with patients with GT/GG genotypes, had a significantly higher rate of achieving RVR (85.2% versus 72.0%, P = 0.017) but did have not a significantly higher rate of achieving SVR (89.4% versus 86.0%). Multivariate analysis revealed that a baseline HCV viral load <400,000 IU/mL was the strongest predictor of RVR [odds ratio (OR) = 4.27, 95% confidence interval (CI) = 2.31-7.87, P < 0.001], and this was followed by advanced liver fibrosis (OR = 0.28, 95% CI = 0.15-0.53, P < 0.001), the carriage of the rs8099917 TT genotype (OR = 3.10, 95% CI = 1.34-7.21, P = 0.008), and the pretreatment level of aspartate aminotransferase (OR = 0.996, 95% CI = 0.99-1.00, P = 0.04). Nevertheless, the achievement of RVR was the single predictor of SVR with an OR of 19.37 (95% CI = 8.89-42.23, P < 0.001), whereas the rs8099917 genotypes played no role in achieving SVR with or without RVR. Conclusion: The rs8099917 TT genotype is significantly independently predictive of RVR, which is the single best predictor of SVR, in Asian HCV-2 patients. © 2010 American Association for the Study of Liver Diseases.