Both Hepatitis C Virus-Specific T Cell Responses and IL28B rs12979860 Single-Nucleotide Polymorphism Genotype Influence Antihepatitis C Virus Treatment Outcome in Patients with Chronic Hepatitis C.

Abstract

Despite new treatments for hepatitis C virus (HCV) infection, IFNα-based regimens still have clinical relevance in special populations of patients and remain the only therapeutic option for many patients. We sought to elucidate the interplay between two relevant factors (IL28B polymorphism and T cell immune responses) involved in the outcome of this therapy in HCV-infected patients. We evaluated 38 patients infected with HCV genotype 1-17 coinfected with HIV-who were undergoing a full course of pegIFNα/RBV therapy. The interdependence and roles of T cell-mediated immune responses and IL28B rs12979860 single-nucleotide polymorphism genotype as predictors of virological response to anti-HCV treatment in patients with chronic hepatitis C were evaluated using nonparametric tests. Factors associated with rapid virological response (RVR) in univariate analysis were presence of CD4 T cell response against NS3 HCV protein, low baseline HCV-RNA, and IL28B CC genotype. Factors associated with sustained virological response (SVR) in univariate analysis were IL28B CC genotype, low baseline HCV-RNA, and presence of CD4 response against NS2. In the multivariate analysis, low baseline HCV-RNA and NS3-specific CD4 response showed a clear trend toward association with RVR (P = 0.09 and P = 0.07, respectively). Regarding SVR, IL28B CC genotype was the strongest predictor (P = 0.02), with presence of NS2-specific CD4 response showing a clear trend (P = 0.09). HCV-specific T cell response influences the outcome of pegIFNα/RBV therapy regardless of IL28B genotype. HCV-specific T cell responses (adaptive immunity) seem to influence viral clearance both in the short and long term during therapy (RVR and SVR), whereas the influence of the IL28B genotype (innate immunity) may be more relevant to the long-lasting therapeutic effect (SVR).