T Helper Type 1/T Helper Type 17-Related Cytokines in Chronic Hepatitis C Patients before and after Interferon and Ribavirin Therapy

Objective: This study examined the T helper (Th) 1/Th17-related cytokines, interferon (IFN)-γ and interleukin (IL)-17 in the serum of biopsy-proven chronic hepatitis C patients before and after IFN and ribavirin therapy to address whether or not viral clearance is related to Th1/Th17 cytokines. Subjects and Methods: The serum levels of IFN-γ and IL-17 were assayed by ELISA on 26 patients with chronic hepatitic C virus (HCV) infection before the start and 3 months after treatment with pegylated IFN-α plus ribavarin and compared with sera from 15 normal control subjects. Results: IFN-γ and IL-17 levels are higher in the serum of patients with chronic hepatitis than in normal controls and these elevated levels were not directly correlated (r = –0.01, p = 0.96 for IFN-γ and r = –0.08, p = 0.66 for IL-17) to the viremic state of the HCV infection. In contrast to IL-17, IFN-γ showed significant reduction after 12 weeks of treatment with pegylated IFN plus ribavirin. However, IFN-γ and IL-17 serum levels were not significantly (p = 0.19 and = 0.70, respectively) different among responders and nonresponders for pegylated IFN plus ribavirin therapy. Conclusion: Our findings suggest that the combined treatment with pegylated IFN-α and ribavirin downmodulates the secretion of key cytokine IFN-γ as early as 12 weeks after treatment in infected patients. These findings could encourage new exciting possibilities for immune-based interventions with the aim of restoring functional antiviral T cell responses combined with improved viral clearance.