Increased numbers of CD5+ CD19+CD1dhighIL-10+ Bregs, CD4+Foxp3+ Tregs, CD4+CXCR5+Foxp3+ follicular regulatory T (TFR) cells in CHB or CHC patients

Background: IL-10(+) regulatory B (Bregs), CD4(+) Foxp3(+) regulatory T (Tregs), and CD4(+)CXCR5(+)Foxp3(+) follicular regulatory T (TFR) cells regulate the progression of infection disease. This study aimed at examining how those cells associated with the development of chronic hepatitis B (CHB) and chronic hepatitis C (CHC) in a Chinese population. Methods: The numbers of circulating IL-10(+) Bregs, Tregs and TFR cells in 31 CHC, 58 CHB patients and 22 healthy controls (HC) were examined by flow cytometry. The potential association of those cells with clinical measures was analyzed. Results: The numbers of CD5(+)CD19(+)CD1d(high)IL-10(+) Bregs, Tregs and TFR cells and the levels of serum IL-10, IFN-gamma and IL-2 in the CHB, and IL-10 and IFN-gamma in the CHC patients were significantly higher than that in the HC (p < 0.05). Furthermore, the numbers of circulating IL-10(+) Bregs and the levels of serum IL-10, but not other cytokines tested were positively correlated with the levels of serum HBV DNA and ALT in the HBeAg- CHB patients as well as HCV RNA and ALT in CHC patients. Additionally, the numbers of circulating TFR cells were positively correlated with the levels of serum HBV DNA and ALT in the CHB patients as well as HCV RNA and ALT in the CHC patients. Conclusions: Increased numbers of circulating IL-10(+) Bregs and TFR cells are associated with poor virus eradication and liver injury in CHB and CHC patients. Furthermore, the levels of serum IL-10 is associated with the hepatic flares.