RESUMO
To assess the percentage of regulatory T cells in peripheral blood of chronic hepatits B [CHB] virus infected patients in comparison with that in healthy controls and to evaluate their suppressive activity on gamma-IFN production by T cells. The percentages of CD4+CD25+ and CD4+CD25+Foxp3+ regulatory T [Treg] cells were quantified in the peripheral blood of 59 chronic hepatitis B patients in comparison with that of 32 controls. And to assess Treg suppressive activity, the percentage of CD4+CD25+Foxp3+Tregs secreting interleukin-10 [IL-10] were evaluated together with the percentage of gamma interferon [gamma-IFN] secreting T cells. This study showed that the percentage of CD4+CD25+Tcells was significantly higher in CHB patients in comparison with healthy controls [mean, 11 +/- 1.7 vs. 36 +/- 4.0 P= 0.007]. A weak positive correlation was observed only between the percentage of CD4+CD25+Foxp3+T cells and serum alanine aminotransferase [ALT] levels [r=0.3, P=0.02]. These findings suggest that Tregs are capable of inhibiting the HBV immune response, which could contribute to persistence of HBV infection. Manipulating these regulatory cells represent an important objective in order to develop new anti-microbial immunotherapies, particularly for chronic infections