Abstract

BACKGROUND
Regulatory T cells (Tregs) may contribute to the immunological hyporesponsiveness against hepatitis B virus (HBV), and this can result in chronic infection. Tregs suppress the T cell responses directed against HBV and they protect hepatocytes by down-regulating the immune responses that cause liver damage, but the role of Tregs has not been well characterized.
METHODS
Fifty four patients were selected and classified into three groups (12 were in the immune-tolerance phase, 35 were in the immune-clearance phase and 7 were in the asymptomatic virus carrier phase). We examined the frequency of CD3+, CD4+ & CD8+ T cells and forkhead box P3 (FoxP3)+ Tregs in the needle-biopsied liver tissue by performing immunohistochemistry.
RESULTS
The FoxP3+ Tregs were mainly located at the portal tracts. In the immune-clearance phase, the frequency of FoxP3+ Tregs was significantly increased compared to that of the immune-tolerance group and the asymptomatic carrier group. Increased FoxP3+ T cells were observed in the patients with a higher histologic inflammatory index. No correlation was observed among the numbers of FoxP3+ Tregs, the serum alanine aminotransferase level, detection of HBeAg and the HBV-DNA viral load.
CONCLUSIONS
FoxP3+ Tregs may play important roles in suppressing the immune response to HBV and the complete elimination of HBV.

• Keywords: Hepatitis B, chronic;T-lymphocytes, regulatory;FoxP3;