[Changes of lymphocyte subsets in acute leukemia patients after HLA-mismatched nonmyeloablative hematopoietic stem cell transplantation].

This study was purposed to investigate the reconstitution of immune system in patients with acute lymphocyte leukemia (ALL) or acute myeloid leukemia (AML) after HLA-mismatched nonmyeloablative hematopoietic stem cell transplantation (NHSCT) and its relation with infection and GVHD. 6 ALL and 4 AML patients having HLA-mismatched related donors received the nonmyeloablative precondition regimen composed of fludarabine (Fln), ATG, Ara-C, CTX and total body irradiation (TBI) in dose 2 Gy. The GVHD was prevented and treated by CsA, anti-CD25 antibody and mycophenolic mofetil (MMF) before and after transplantation. The flow cytometry was used to detect the changes of total T cells, help/inducer T cells, suppressor/killer T cells, gamma/delta T cells, B cells, NK cells, NKT cells, regulatory T cells, activated T cells, naive T cells, memory T cells and ratio of CD4/CD8 in patients with remission resulting from chemotherapy before transplantation, and analyse the relation of immunofunctional cells to infection and GVHD after transplantation, compare the difference in recovery of immune system of ALL and AML patients. The results showed that the recovery of total lymphocytes and lymphocyte subsets displayed one's own regular pattern. As compared with patients without GVHD, the counts of lymphocyte subsets in patients with GVHD was higher, while the counts of gamma/delta T cells, regulatory T cells, NK cells, the counts of B cells, NK cells, naive cells and CD4/CD8 ratio as well as the counts of B cells, naive T cells and NK cells were lower at 1 month, 2 - 3 months and 6 - 8 months after transplantation respectively. The total T cells and subsets recovered slowly, but NK cells and NKT cells recovered rapidly in patients with infection at early period after transplantation, the B cells and naive B cells recovered rapidly at 3 months after transplantation. There was no difference in lymphocyte recovery between ALL and AML patients. It is concluded that the analysis of each lymphocyte subsets may indirectly show the recovery of thymus function in patients, the changes of NK cells, B cells and naive T cells have an important significance for identifying and forecasting the GVHD and infection.