Background: T follicular helper (T(FH)) cells are a subpopulation of T-helper cells which regulate humoral immune responses. The role of T(FH) cells in viral infection is unclear. This study examined the possible involvement of CD4(+)CXCR5(+) T(FH) cells in chronic hepatitis C (HCV) infection.
Methods: The percentages of peripheral blood CD4(+)CXCR5(+) T(FH) cells, inducible T-cell costimulator cells, and/or programmed death 1-positive CD4(+)CXCR5(+) T(FH) cells in 39 HCV-infected patients, 12 patients with spontaneously resolved HCV infection (SR-HCV), and 12 healthy controls were characterized by flow cytometry analysis. The subjects' serum HCV RNA loads and alanine aminotransferase and aspartate aminotransferase levels were measured. The potential association of the percentage of peripheral CD4(+)CXCR5(+) T(FH) cells with clinical data was analyzed.
Results: Higher percentages of peripheral blood CD4(+)CXCR5(+) T(FH) cells were found in SR-HCV and HCV-infected patients as compared with healthy controls. Interestingly, a statistically significant negative correlation was found between the percentage of CD4(+)CXCR5(+) T(FH) cells and the HCV RNA load.
Conclusions: These data suggest that CD4(+)CXCR5(+) T(FH) cells may participate in HCV-related immune responses. Increased T(FH) cells in peripheral blood may help to control HCV infection.