Impaired Thymic Output in Patients with Chronic Hepatitis C Virus Infection

Altered T cell homeostasis in chronic hepatitis C virus ( HCV ) infection has been demonstrated. However, it is unknown whether fibrosis is associated with more perturbed T cell homeostasis in chronic HCV infection. The aim of this study was to examine and compare T cell subsets including recent thymic emigrants ( RTE ), naive, memory, senescent, apoptotic and IL ‐7 receptor α ( CD 127) expressing CD 4 + and CD 8 + T cells as well as telomere length and interferon‐γ production in HCV ‐infected patients with ( n  = 25) and without ( n  = 26) fibrosis as well as in healthy controls ( n  = 24). Decreased proportions of CD 4 + and CD 8 + RTE were found in HCV ‐infected patients, especially in HCV ‐infected patients with fibrosis (14.3% (9.7–23.0) and 28.8% (16.1–40.5), respectively) compared with healthy controls (24.2% (16.3–32.1), P  = 0.004 and 39.1% (31.6–55.0), P  = 0.010, respectively). Furthermore, HCV ‐infected patients with fibrosis presented with a higher proportion of CD 4 + T cells expressing CD 127 compared with HCV ‐infected patients without fibrosis [88.4% (84.5–91.0) versus 83.8% (79.9–86.8), P  = 0.016]. Thus, impaired thymic output in HCV infection was found, and high proportion of CD 127 + T cells may illustrate a compensatory mechanism to preserve T cell counts.