[Recovery of Early and Mature T Lymphocyte Subsets after Allogeneic Hematopoietic Stem Cell Transplantation].

To study the reconstituion of the T-cell populations after allogeneic hematopoietic stem cell transplantation, the peripheral blood samples obtained at different time points post-transplantation in 21 patients were analyzed using CD5-PE and CD3-FITC with flow cytometry. During the first 3 months after transplantation, CD3(-) CD5(+) T cell subsets, representing early thymocytes, remained below normal level, whereas CD3(+) CD5(+) T cell subsets, representing mature T cells, regenerated to normal level. In 9 patients who developed acute graft-versus-host disease (GVHD), the percentage of CD3(+) CD5(+) T cell subsets was significantly higher than that in patients who did not develop acute GVHD (P < 0.05). These results demonstrated that the early recovery of T cells is mainly due to the expansion of mature T cell populations, and the over-expansion of mature T (CD3(+) CD5(+)) cells is responsible for the development of acute GVHD.