Effect of antiviral treatment of chronic hepatitis C on the frequency of regulatory T cells, T-cell activation, and serum levels of TGF-beta.

The aim was to analyze T-regulatory cells (Tregs), activated CD8(+) T cells, and transforming growth factor-beta (TGF)-β in hepatitis C patients. We enrolled 31 patients with chronic genotype 1 hepatitis C virus (HCV) infection, 30 seropositive persons with spontaneous HCV elimination, and 23 healthy volunteers. The patients were examined at the beginning of the interferon-alpha (IFN-α)-based therapy (baseline) and at weeks 4 (W4) and 12 (W12) of the therapy. The percentage of Tregs and the expression of activation markers CD38 and HLA-DR on CD8(+) T cells were analyzed in the peripheral blood by flow cytometry. Serum levels of TGF-β were measured in a multiplex assay using flow cytometry. The percentage of Tregs in patients was higher than in controls and seropositive persons. Similarly, the percentage of CD8(+) T cells expressing CD38 and HLA-DR was higher in patients compared with controls and seropositive persons. Chronic HCV infection is associated with elevated circulating Tregs and activated CD8(+) T cells. During IFN-α-based therapy these cells gradually increase, whereas TGF-β serum levels decrease.