T‐cell homeostasis in chronic HCV‐infected patients treated with interferon and ribavirin or an interferon‐free regimen

Direct‐acting antiviral has replaced pegylated interferon‐α and ribavirin‐based treatment in the treatment of chronic hepatitis C virus (HCV) infection. While interferon‐α is immune modulating and causes lymphopenia, interferon‐free regimens seem to be well‐tolerated. This study aimed to compare T‐cell homeostasis before, during, and after HCV treatment with or without interferon‐α in patients with chronic HCV infection. A total of 20 patients with chronic HCV infection were treated with pegylated interferon‐α and ribavirin, and six patients were treated with an interferon‐free regimen. All patients were treated for a minimum of 12 weeks. Interferon‐α treatment caused an increase in the density of the receptor for IL‐7 (IL‐7Rα) during treatment, while interferon‐free regimens caused a decrease in IL‐7Rα density. After a sustained viral response, proportions of IL‐7Rα+ T cells and IL‐7Rα density decreased compared to prior treatment values. Finally, a proportion of CD8+ effector memory was lower while proportion of apoptotic T cells was higher after sustained virologic response compared to prior treatment. Despite lymphopenia during interferon, alterations in T‐cell homeostasis during treatment were relatively similar in patients receiving interferon‐based treatment and in patients receiving interferon‐free treatment, and alterations during and after treatment seem to illustrate a reduced need for high levels of T cells aimed at controlling infection.