[Clinical research on reconstitution of CD4+CD25+ T cells after haploidentical bone marrow transplantation]

The aim of this study was to investigate the reconstitution of CD4(+)CD25(+) T cells after haplo-identical bone marrow transplantation (hiBMT) and its correlation with graft versus host disease (GVHD) and relapse. Peripheral blood samples from 27 patients after hiBMT were harvested and the percentage and absolute counts of CD4(+)CD25(+) T cells were detected by flow cytometry. The correlations of GVHD occurrence and disease relapse with the reconstitution of CD4(+)CD25(+) T cells were analyzed. The results showed that the percentage of CD4(+)CD25(+) T cells of peripheral blood samples increased significantly after G-CSF priming. At day 30 after hiBMT, CD4(+)CD25(+) T cells were recovered to the 20% of normal level, followed by a slowly process in 3 months, and up to one half of the normal level at 180 days. There was no evidence to prove relationship between CD4(+)CD25(+) T cells and acute GVHD, while CD4(+)CD25(+) T cells were increased significantly in the chronic GVHD group. The absolute count of CD4(+)CD25(+) T cells showed no relations with relapse of leukemia during the first year after hiBMT. In conclusions, chronic but not acute GVHD was in relation to the reconstitution of CD4(+)CD25(+) T cells based on the anti-CD25 antibody therapy model for the prevention of GVHD after hiBMT. Further investigation is needed to clarify whether the relapse of leukemia after hiBMT is related to the reconstitution of CD4(+)CD25(+) T cells.