Genetic polymorphisms of IL28b gene as predictors of response to dual therapy in genotypes 1 and 4-HCV and HIV/HCV-infected patients.

We describe the genotypes and allele distribution of interleukin 28B (IL28B) rs12979860 and rs8099917 single nucleotide polymorphisms (SNPs) in hepatitis C virus (HCV) G1-4 infected patients, to assess predictive ability and to determine whether the combined determination of two IL28B SNPs might improve sustained virologic response (SVR) prediction of both in HCV mono- and HIV/HCV co-infected patients. IL28B SNPs were genotyped in 269 patients, 181 mono- and 88 co-infected, treated with pegylated interferon and ribavirin. Data stratified by HCV mono- and HCV/HIV co-infected patients showed that 58% and 31% of the rs12979860CC carriers and 49% and 21% of the rs8099917TT carriers had SVR. IL28B SNPs, HCV mono-infection and HCV RNA load were associated with SVR as independent predictors in the two study groups as a whole. ROC curve analyses in the two populations separately, based on gender, age, baseline HCV RNA load and rs12979860/rs8099917 revealed similar receiver operating characteristics (ROC) areas under the curve values. Combining the determination of IL28B SNPs, rs8099917 genotyping improved the response prediction in rs12979860CT carriers only in mono-infected patients. In the era of direct-acting antiviral agents, adopting SVR baseline predictors to orientate naïve-patient management represents an important issue. A model involving IL28B SNPs appears able to predict SVR in both populations.