The role of CD4+CD25+ T regulatory cells (Tregs) in immune tolerance in experimental transplantation is very important but the clinical significance of circulating Tregs in the peripheral blood is undetermined. We evaluated the association between the frequency of T cell activation markers CD25 and CD71 and clinical parameters that may affect the level of these T cell markers. In 47peditric kidney transplant (KT) recipients and 20 healthy controls, the frequency of T cell activation markers, CD25 and CD71 was measured with flow cytometry after transplantation. Two clinical protocols of induction immunosuppression were used: (1) anti-thymocyte globulin (THYMO) group (n =29) and Basiliximab (BSX) group (n=10). The percentage of circulating CD25 after KT was significantly lower than that in the controls. There is no significant difference between KT and the controls s regard to circulating CD71. The percentage of CD25 was significantly increased in children with acute rejection compare...
