Relevance of T helper Type 1, 2 and 17 Cytokine Profiles to the Outcome of Therapy in Hepatitis C Patients

Background: This study aimed to investigate the relationship of T helper type (Th)1/Th2/Th17 type cytokines produced by chronically hepatitis C virus (HCV)-infected patients in response to pegylated interferon-α plus ribavirin (Peg-IFN/RBV) therapy. These finding will help us to identify the type of cytokines which participate in restoring functional antiviral T cell responses resulting in improved viral clearance. Methods and results: Sixty genotype-4 HCV-infected patients received Peg-IFN/RBV therapy for 12 weeks. Levels of Th1 cytokines (IL-2, IL-8, IL-12, TNFα, IFNγ), Th2 cytokines (IL-4, IL-6, IL-10) and Th17 cytokines (IL-17A, IL-17F) were estimated by ELISA. In post-treatment samples, mean levels of Th1 cytokines IL-12 and IFNγ were significantly higher in patients with an early virologic response (EVR) when compared to non-EVR. In contrast, mean levels of IL-17A and IL-17F in post-treatment samples were significantly higher in non-EVR patients compared to EVR patients. Interestingly, in post-treatment samples the anti-inflammatory Th2 cytokines IL-4 and IL-6 were produced at significantly higher levels in non-EVR patients than in EVR patients. Also, after treatment, the ratios of pro-inflammatory to anti-inflammatory cytokines were higher in EVR as compared to non-EVR patients. Conclusion: A pattern of stronger Th1- and weak Th17 reactivity in HCV-infected patients supports a favorable response to Peg-IFN/RBV therapy.