Abstract: Objective To understand the variation of the CD4⁺CD25⁺Foxp3⁺ regulatory T cells in HIV-infected patients during early highly active anti-retroviral therapy(HAART) and the function of Treg cells during antiviral therapy.Methods Data of 21 HIV-infected patients undergoing HAART were analyzed in this study.This was a prospective study which enrolled treatment-naive HIV-infected patients just prior to starting HAART;levels of Treg were measured by flow cytometry at weeks 0,2,4,8,12 of treatment.The relationship between Treg cells and immunologic activation was studied.Results Treg cell counts were higher when treatment with HAART was started,especially during first 4 weeks,then the trend was slowed down,so was the ratio of Treg.As HAART went on,the expression of CD8⁺CD38⁺ was reduced.The Treg counts was inversely correlated with immune activation level for treatment-naive patients.Conclusion The declined ratio of activated CD8⁺ may be related to the number of elevated Treg cells.The earlier the Treg cells resumed,the more the proportion of activated CD8⁺ T cells declined.

Key words: regulatory T cells, human immunodeficiency virus, highly active anti-retroviral therapy