Genetic host factors may modify the course of the hepatitis C virus (HCV) infection. Very recently, a genome-wide scan that reported association of the IL28B locus with response to treatment in HCV infection was published. The aim of the current study was to investigate the relationship of this locus with outcome of HCV infection in a cohort constituted by a total of 731 Spanish individuals. From these, 284 were subjects with persistent infection, 69 were individuals who naturally cleared the virus, and 378 were noninfected subjects. Genotyping of the rs12979860 (C>T) in the IL28B locus was performed using a TaqMan 5' allelic discrimination assay. The CC genotype was overrepresented among patients infected with viral genotypes non-1 (66.7% versus 39.1% in patients infected with viral genotype-1, P = 8.5 x 10(-5), odds ratio [OR] = 0.32, 95% confidence interval [CI] 0.17-0.60); patients with spontaneous resolution of infection (72.5% versus 45.6% of the individuals with persistent infection, P = 6.2 x 10(-5), OR = 0.32; 95%CI, 0.18-0.57); and lastly, patients with sustained response (60.2% versus 32.1% found in patients with nonsustained response, P = 3.1 x 10(-5), OR = 0.31; 95%CI, 0.17-0.56).
Conclusion: We have found different rates of viral genotype infection depending on the IL28B variant as well as an association of this locus with natural and treatment-mediated response.