The genotype CC of IL-28B SNP rs12979860 is significantly associated with a sustained virological response in chronic HCV-infected Pakistani patients.

Abstract

To evaluate the association of genetic variation in interleukin 28B (IL-28B) gene and viral factors with treatment outcome in chronic hepatitis C virus (HCV)-infected patients in Pakistan. Patients with chronic HCV infection who received interferon plus ribavirin combination therapy were enrolled in the study. The viral loads were checked at the third and sixth month of treatment and 6 months after the completion of the treatment. Genotyping of single-nucleotide polymorphism (SNP) rs12979860 of IL-28B gene was performed by the restriction fragment length polymorphism method and direct sequence analysis. A total of 111 patients successfully completed antiviral therapy and the follow-up period. Early virological response (EVR) and a sustained virological response (SVR) were achieved in 92 and 91 patients, respectively. Patients infected with HCV genotype 3a had a higher SVR rate compared with other HCV genotypes. A higher C allele frequency (81.9%) was observed in patients with SVR than those with non-SVR (P = 0.00001). The odds ratio of achieving SVR was more than 10-fold greater for the CC genotype than the CT/TT genotypes of SNP rs12979860 (OR 10.351, 95% CI 1.925-55.653, P = 0.006). Other positive predictors observed for SVR were female gender and EVR. The CC genotype of IL-28B SNP rs12979860 is an independent predictive factor for SVR in chronic HCV-infected patients in Pakistan.