Circulating T follicular helper cells are associated with rapid virological response in chronic hepatitis C patients undergoing peginterferon therapy.

Abstract Background Chronic hepatitis C virus (HCV) infection is associated with abnormal T cell and B cell immune responses. T follicular helper (TFH) cells are a subset of CD4 + T-helper cells and can activate B cells. This study aimed to investigate the role of circulating CXCR5 +  CD4 + TFH cells, CD19 + B cells and the associated cytokines in patients with chronic HCV infection. Methods The frequencies and phenotypes of circulating TFH cells and B cell subtypes were characterized using flow cytometry in chronic hepatitis C (CHC) patients and in healthy controls (HCs). The expression of IFN-γ, IL-12p70, IL-5, IL-13, IL-17F, IL-22, IL-23, TGF-β1, IL-10 and IL-21 associated with Th1, Th2, Th17, regulatory T cells (Treg) and TFH cells were analyzed using a Quantibody array. The patients' clinical parameters were detected, and the effect of pegylated interferon plus ribavirin treatment on these immune indicators in CHC patients was determined. Results The frequency of CXCR5 +  CD4 + T cells was significantly higher in CHC patients compared to HCs. There were no significant differences in CD19 + B cells, CD19 +  CD27 + B cells, or CD19 +  CD38 + B cells between CHC patients and HCs. The expressions of cytokines associated with the CD4 + Th lineage were higher in CHC patients than in HCs, except for IL-21. Patients with rapid virological response (RVR) showed an increased CXCR5 +  CD4 + T cell count and decreased PD-1 + CXCR5 +  CD4 + T cell count compared to non-RVR patients after PEG-IFN/ribavirin treatment. Conclusions These data demonstrate that circulating TFH cells and CD4 + Th lineage-associated cytokines may play a role in HCV-related immune responses.