Decrease of CD4+CD25+ regulatory T cells and TGF-β at early immune reconstitution is associated to the onset and severity of graft-versus-host disease following allogeneic haematogenesis stem cell transplantation

Graft-versus-host disease (GVHD) is a frequent and life threatening complication of allogeneic haematogenesis stem cell transplantation (aHSCT). The correlation of CD4+CD25+ regulatory T cells (Tregs) in the patients after aHSCT to the occurrence and severity of acute and chronic GVHD (aGVHD and cGVHD) is not fully investigated. Here, we examined the levels of CD4+CD25+ Tregs by assessment of CD4+CD25high and CD4+CD25+CD127low in peripheral blood, and the levels of serum TGF-β and TNF-α in 56 patients at early immune reconstitution following aHSCT. Our data showed a significant reduction in the frequency of Tregs in patients with grades II–IV aGVHD and extensive cGVHD compared to healthy controls. Moreover, a decreased level of CD4+CD25+ Tregs was correlated to increased severity of GVHD. The levels of CD4+CD25+ Tregs in non-GVHD groups were however significantly higher than that in healthy controls. A significant decrease in the levels of TGF-β and a significant increase the levels of TNF-α was also seen with increased severity of GVHD. This study suggested that measurement of CD4+CD25+ Tregs along with serum TGF-β and TNF-α at early immune reconstruction after aHSCT may indicate the onset and severity of both aGVHD and cGVHD.