CD4～+CD25～(high) Regulatory T-cells And NKT Cells In Myelodysplastic Syndromes (MDS)

Objectives: To determine the correlation between the CD4⁺CD25^high regulatory T-cells,NKT cells and the pathogenesis of myelodysplastic syndromes (MDS), so as to the connection between the two kinds of cells and the progression of MDS, We investigated the populations of CD4⁺CD25^highT cells,NKT cells and NK cells in peripheral blood of MDS patients and acute myelogenous leukemia (AML) patients progressed from MDS.Material and Methods: The populations of CD4⁺CD25^highT cells,NKT cells and NK cells in the peripheral blood were measured by flow cytometry in 30 patients who were MDS patients or AML patients progressed from MDS, and in 20 healthy volunteers. Then we analyzed the relationship among the three cells, and the correlation between the populations of CD4⁺CD25^highT cells,NKT cells and MDS classifications and prognosis degrees.Result: The population of CD4⁺CD25^highT cells and the percentage of CD4⁺CD25^highT cells in CD4⁺ cells in the group of patients who were MDS patients or AML patients progressed from MDS were significantly higher than them in the group of healthy volunteers; the population of NKT cells in patients was significantly lower than healthy volunteers; the number of CD3⁺ and CD4⁺ cells was significantly lower than healthy volunteers; NKT cells was decreased in patients group,but there was no notable difference. In the patients group, the percentage of CD4⁺CD25^highT cells in CD4⁺ cells of AML patients was significantly higher than RCMD and RAEB patients. There were no significant difference of the numbers of CD4⁺CD25^highT cells,NKT cells and NK cells in the three groups. The population of CD4⁺CD25^highT cells and the percentage of CD4⁺CD25^highT cells in CD4⁺ cells in the intermediate risk patients were markedly lower than AML patients, and intermediate risk patients CD4⁺CD25^highT/CD4+ percentage markedly lower than high risk patients; the means of NKT cells among the three groups were gradually increased along with the increasing risk degrees. The percentage of CD4⁺CD25^highT cells in CD4⁺ cells in patients with BM blasts≥5ï¼…was significantly higher in comparison to＜5ï¼…BM blasts; there were no significant difference of the number of CD4⁺CD25^highT cells,NKT cells and NK cells in the two groups. There had a significant linear correlation between CD4⁺CD25^highT/CD4+ percentage and the number of blasts in BM.Conclusion This study suggested that:1, The numbers of CD3⁺ cells,CD4⁺ cells and NKT cells in patients group significantly decreased. It suggested that there existed the impairment of tumor immunity in MDS patients, which associated with CD4⁺CD25^high regulatory T-cells.2, The population of CD4⁺CD25^high regulatory T-cells in the patients group was markedly higher than healthy control. The percentage of CD4⁺CD25^high/CD4+ significantly correlated with the number of blasts in BM, which increased alone with the risk level increasing. These indicated that there was a tight correlation between CD4⁺CD25^high regulatory T-cells and the pathogenesis and progression of MDS.3, NKT cells play a helper role of CD4⁺CD25^high regulatory T-cells in the pathogenesis and progression of MDS.