Decrease in regulatory T-cell function in chronic hepatitis C patients receiving pegylated-interferon plus ribavirin

Summary Objectives Regulatory T-cells (Tregs) play an important role in the pathogenesis of chronic hepatitis C (CHC) infection. Pegylated interferon is the standard therapy for CHC patients in Asian countries. This study aimed to evaluate the frequency and function of Tregs in CHC patients receiving combination therapy. Methods CHC patients ( n = 30) who had elevated alanine aminotransferase and underwent combination therapy were included. Clinical data and Treg function were checked at baseline, 12 weeks after treatment, at the end of treatment, and at the end of 24 weeks of follow-up. Treg immunosuppressive activity was measured as the inhibition ratio of conventional T-cell proliferation. Results Treg-mediated immunosuppression was significantly lower during therapy than at baseline (baseline 44.45%; 12 weeks 18.41% ( p = 0.042); end of treatment 22.62% ( p = 0.036); end of follow-up 17.46% ( p = 0.003)). Treg-mediated immunosuppression was higher in patients with a sustained virological response (SVR) than in those without SVR at the end of follow-up (SVR 24.20%, non-SVR 6.87%; p = 0.030). Conclusion Treg-mediated immunosuppression was lower during and after combination therapy, regardless of the treatment response, and higher in patients with SVR than in those without SVR at the end of follow-up.