Dynamics of lymphocyte subpopulations in patients with chronic hepatitis C virus infection during pegylated interferon-alpha2a and ribavirin treatment

The current standard therapy for chronic hepatitis C virus (HCV) infection consists of pegylated interferon-alpha (pegIFN-α) and ribavirin, an effective treatment owing to its immunomodulatory and antiviral actions. Different dynamics of lymphocyte subpopulations during combined antiviral treatment in patients with chronic HCV infection and in relation to virological outcome have been described, including an increase in regulatory T cells (Tregs), suggesting that immunomodulation fluctuates during antiviral treatment. Higher CD81 expression levels have been described in CD19+ B cells as well as higher Tregs percentage before starting antiviral treatment in non-responder HCV patients than in sustained virological responder HCV patients suggesting that these lymphocyte subpopulations might be useful as immunological prognostic factors for pegIFN-α2a and ribavirin treatment response in chronic HCV infection. Interferon-α therapy can cause numerous side-effects, including thyroid disease. In this sense, the dynamics of innate and acquired immune subpopulations through antiviral treatment in patients with HCV developing interferon-induced thyroiditis (IIT) have recently been described. Specifically, these patients presented a higher Th1 response and an increase in Tregs percentage compared with age- and sex-matched subjects with chronic HCV who did not develop thyroid disease during treatment, suggesting a possible role of these lymphocyte subpopulations in patients with HCV developing IIT. © 2012 by Nova Science Publishers, Inc. All rights reserved.