ABSTRACT
<p><b>OBJECTIVE</b>To investigate the level of CD4+ CD25+ Foxp3+ regulatory T cells and observe relation between expression of Foxp3 and CD127 in peripheral blood of chronic HBV infection.</p><p><b>METHODS</b>CD4+ CD25+ Foxp3+ and CD4+ CD25+ CD127low Treg in peripheral blood from 34 patients of immune tolerance stage, 26 patients of immune clearance stage and 31 patients of non-active status were quantitatively analyzed by flow cytometry.</p><p><b>RESULTS</b>Immune tolerance group presented a higher fraction of CD4+ CD25+ Foxp3+ and CD4+ CD25+ CD127low Treg than non-active group in chronic HBV infection (Z = -2.693, P = 0.007 and t = 3.251, P = 0.002), and HBV positive group also presented a higher fraction than non-active group (t = 2.266, P = 0.026 and t = 3.208, P = 0.002), But ALT normal group is similar to ALT abnormal group (P > 0.05). In this study, the relation between expression of CD127low and Foxp3+ from CD4+ CD25+ regulatory T cells was observed, and CD4+ CD25+ CD127low Treg presented a higher fraction than CD4+ CD25+ Foxp3+ Treg.</p><p><b>CONCLUSION</b>Peripheral Treg in HBV active replication group is higher than HBV negative group of chronic HBV infection. Expression of CD127low is consistent with Foxp3+ in CD4+ CD25+ regulatory T cells, but the former is significantly higher than the latter.</p>