[Detection and significance of CD4+ CD25int/high CD127low regulatory T cells in pediatric aplastic anemia].

Objective: To study the expression of CD4+ CD25int/high CD127low regulatory T cells in peripheral blood (PB) and its relation to the quantity of Hb, WBC and platelet (Plt) in children with aplastic anemia (AA).

Methods: Expression of CD4+ CD25int/high CD127low in PB was detected by flow cytometry in 22 children with AA before and after treatment and in 15 healthy controls. The relationships between CD4+CD25highCD127low and the quantity of Hb, WBC and Plt were evaluated.

Results: Compared to controls, the percentages of CD4+ CD25+/CD4+, CD4+CD25high/CD4+, CD4+ CD25+ CD127low/CD4+ and CD4+CD25highCD127low/CD4+ in PB of AA patients decreased markedly at the active phase (P﹤0.05). By the recovery phase, the percentages of CD4+CD25+/CD4+, CD4+CD25high/CD4+, CD4+ CD25+ CD127low/CD4+ and CD4+CD25highCD127low/CD4+ increased significantly to the levels similar to the controls. There were significant positive relationships between the expression of CD4+CD25highCD127low cells and the quantity of Hb, WBC and Plt (r=0.499, 0.526, 0.540 respectively; P﹤0.05).

Conclusions: The decrease of the percentage of CD4+CD25int/highCD127low regulatory T cells might be associated with the development of pediatric AA. The CD4+CD25int/highCD127low regulatory T cells can serve as a marker for the evaluation of disease severity as well as a target of further study on immune treatment of AA.