Abstract:

Objective   To investigate the role of CD4+T cell subsets in the immune pathogenesis of aplastic anemia (AA), myelodysplastic syndromes(MDS), and acute myeloid leukemia(AML). Methods   Flow cytometry was used to detect the proportion of T helper and Treg cells in peripheral blood mononuclear cells  of 48 MDS, 25 AA, 12 AML patients and 8 normal controls. Results   Compared with the control group, the percentages of Th1 and Th17 cells and Th1/Th2 were higher， but the percentages of Th2 and Treg cells were lower in the AA group(P＜0.05). There was no significant difference in the percentages of Th1, Th2, Treg cells and Th1/Th2 between the MDS group and the control group(P>0.05)，but the percentages of Th17 and Treg cells were higher in the MDS group (P＜0.05). The percentages of Th1, Th17 cells and Th1/Th2 were higher and the percentage of Th2 cells was lower in the MDS-RA group, but there was no difference in the percentage of Treg cells between the MDS-RA group and the control group (P>0.05). In the AML and MDS-RAEB groups, the percentages of Th1 and Th17 cells and Th1/Th2 were significantly lower and the percentages of Th2 and Treg cells were higher than the normal controls (P＜0.05). Conclusions   Immune status is different in AA， variant MDS stages and AML. Immune-mediated excessive apoptosis could induce bone marrow failure in AA and the early stage of MDS. The large accumulation of abnormal clones could induce bone marrow failure in AML and late stage of MDS.

Key words: Myelodysplastic syndromes; Aplastic anemia; Acute myeloid leukemia; T helper cells; Treg cells; Flow cytometry