Changes in circulating follicular helper T cells in peripheral blood of patients with acute hepatitis C virus infection

BACKGROUND To investigate the changes in circulating follicular helper T cells (cTfh) in peripheral blood of patients with acute hepatitis C virus (HCV) infection and its correlation with symptom severity of the disease. METHODS A total of 105 subjects were enrolled in this study, including 35 healthy people, 35 patients with acute HCV infection and 35 acute HCV patients with antiviral therapy. Flow cytometry was used to detect the expression of molecular markers related to the surface of cTfh cells, such as CD69, HLA-DR and CD57, and ELISA was used to detect the secretion of cytokines (IL-21, IL-4) in each group. The relationship between these markers and disease was analyzed statistically. RESULTS Flow cytometry analysis demonstrated that the percentage of CD69 in peripheral blood of patients with acute hepatitis C infection was (18.90%±9.29%) significantly higher than that of normal control group (5.10%±4.21%) and antiviral treatment group (11.50%±5.38%). The difference was statistically significant (P<0.05). The results of HLA-DR and CD57 were consistent with CD69. The serum levels of IL-4 and IL-21 in the acute HCV infection group were significantly higher than those in the treatment and the control groups. After antiviral treatment, IL-4 and IL-21 levels significantly decreased but remained higher than those in the control group. This showed that antiviral treatment was effective, and the difference was statistically significant (P<0.05). The ratio of cTfh in infected group was negatively correlated with HCV RNA content (r=-0.6858, P=0.0028). CONCLUSIONS Antiviral immune response in patients with acute hepatitis C infection may be related to the proportion of T helper cells in peripheral blood circulation follicles. Dynamic detection of the number of T helper cells in clinical practice is conducive to identifying more effective methods to treat acute hepatitis C infection, which has important theoretical and clinical significance.