Different core-specific T cell subsets are expanded in chronic hepatitis C with advanced liver disease.

Chronic hepatitis C (CHC) is frequently related to liver fibrosis, and several studies have suggested that the immunological activity of HCV antigens contributes to hepatic damage. In the present study, among structural and non-structural HCV antigens, elevatedIL-1ß, IL-6, IL-17 levels were secreted by PBMC cultures obtained from CHC patients following stimulation with core antigen. Moreover, the percentage of core-specific IL-6+IL-17+(CD4+ and CD8+) T cells was significantly higher in patients with worsehepatic lesions, determined on the Metavir scale. When compared with healthy subjects, the percentage of circulating Treg cells was elevated in CHC patients, mainly among those with advanced liver fibrosis. Nevertheless, in this last group of patients, the proportion of CD39+ Treg subsets was very low. Finally, the percentage of senescent (CD57+ CD28-) and exhausted (PD-1+CD28+) core-specific T cells in CHC patients was also found to be a result of fibrotic hepatic status. In summary, imbalances between different core-specific T cell subsets are associated with liver fibrosis severity.

The proportion of different interleukin-17-producing T-cell subsets is associated with liver fibrosis in chronic hepatitis C.

Studies have suggested the pivotal role of T helper type 1 (Th1) -related cytokines on the outcome of hepatitis C virus (HCV) infection. Nevertheless, the role of different interleukin-17 (IL-17) -secreting T cells on chronic hepatitis C (CHC) is less clear. Here, the in vivo IL-1ß, IL-6, and IL-17 levels were positively correlated with both alanine transaminase (ALT) levels and hepatic lesions. When compared with the control group, CHC patients showed a lower proportion of IL-17-secreting (CD4+ and CD8+ ) T cells capable of simultaneously producing IL-21. Moreover, the percentage of IL-10-secreting Th17 cells was also lower in CHC patients. Notably, advanced liver lesions were observed among those patients with lower percentage levels of IL-17-producing T cells positive for IL-21, interferon-γ (IFN-γ) and IL-10. In contrast, the severity of hepatic damage was associated with peripheral single IL-17+ T cells. The percentage of IL-17+ IL-21- IFN-γ+ (CD4+ and CD8+ ) T-cell phenotypes was positively associated with plasma CD14 levels. Finally, elevated levels of circulating CD14 were detected among CHC patients with extensive liver damage. In summary, although preliminary, our results suggest that a balance between different IL-17-producing T cells, associated with peripheral levels of CD14, may be a progress marker for liver disease in chronically HCV-infected patients.