Effects Of Hypomethylating Agents On Tregs,Th1,Th2 And NKT In Patients With AML/MDS

Background:HMAs(Dexitabine and azacytidine)have been approved by FDA for myelodysplastic syndrome and acute myeloid leukemia in older patients or with underlying diseases that cannot tolerate intensive therapy.The therapeutic effect of HMAs is reflected not only in direct cytotoxicity and reversal of methylation of tumor suppressor gene promoter,but also in its effect on tumor immune regulation of AML and MDS.The purpose of this study was to analyze the relative content of immune cells(Tregs cells,Th1 cells,Th2 cells,NKT cells)in patients with AML and MDS after initial diagnosis and treatment(including HMAs treatment group and non-HMAs treatment group).We intend to investigate the immune mechanism and the effect of HMAs on tumor immune response in patients with AML and MDS.Methods:The samples were collected from 15 patients with MDS,36 patients with AML and 7 patients with iron deficiency anemia(The control group)in the Department of Hematology,the first affiliated Hospital of Kunming Medical University from October 2019 to February 2020.3-4 ml of peripheral blood was collected and the relative contents of Tregs,Th1,Th2 and NKT cells were detected by flow cytometry within 36 hours.The experimental data were analyzed by SPSS23.0 software,P?0.05 means the difference is statistically significantResults:1.Tregs cells:1.1the relative content of Tregs cells in AML and MDS groups was higher than that in the control group(P=0.01).1.2 there was no significant difference in the relative content of Tregs between the HMAs treatment group and the AML and MDS groups(P=0.05),but the Tregs content of both groups was lower than that of the non-HMAs group(P=0.003).In patients with AML and MDS,there was no significant difference in Tregs content between HMAs treatment group(D28)and HMAs treatment group(D14),but Tregs content in HMAs treatment group(D28)was lower than that in HMAs treatment group(D14).1.4 in AML patients,the Tregs content in HMAs treatment group(D28)was significantly lower than that in non-HMAs treatment group(P=0.036),and there was no significant difference compared with newly diagnosed group and HMAs treatment group(D14)(P=0.586)1.5 In the MDS patients,there was no significant difference in Tregs relative content among newly diagnosed group,HMAs treatment group(D14)and HMAs treatment group(D28).In patients with AML and MDS,the relative content of Tregs in the control group was not significantly different from that in the HMAs group(P=0.662),but significantly lower than that in the non-HMAs group(P=0.001),and in the patients with AML and MDS,there was no significant difference in the relative content of Tregs between the DAC treatment group and the AZA treatment group(P=0.405).1.8 there was no significant difference in the relative content of Tregs between the remission group after HMAs treatment,the non-remission group after HMAs treatment and the non-HMAs treatment group(P=0.01).2.Th cells:2.1 There was no significant difference in the relative contents of Thl and Th2 cells and the ratio of Th1/Th2 cells between the newly diagnosed AML and MDS groups and the control group(P=0.224).The Th2 cells in the newly diagnosed AML and MDS groups were higher than those in the control group,while the Th1/Th2 cells in the AML and MDS groups were lower than those in the control group.In patients with AML,there was no significant difference in the relative content of Thl and Th2 cells and the ratio of Th1/Th2 cells in peripheral blood between the newly diagnosed group and the control group.However,there was a downward trend of Th1 cells in the peripheral blood of the newly diagnosed patients with AML compared with the control group.2.2 Patients with AML and MDS,there was no significant difference in the relative content of Th1,Th2 cells and the ratio of Th1/Th2 cells in peripheral blood among newly diagnosed group,HMAs treatment group and non-HMAs treatment group(P= 0.05).However,it was observed that Th1 cells in HMAs group were higher than those in non-HMAs treatment group.3.NKT cells:the content of NKT cells in control group was higher than that in AML and MDS groups(P=0.01).3.2 in patients with AML and MDS,the content of NKT cells in the HMAs treatment group was significantly higher than that in the newly diagnosed group(P=0.004),but there was no significant difference between the patients treated with non-HMAs treatment and the newly diagnosed patients(P=0.055).In AML patients,the content of NKT cells in HMAs treatment group and non-HMAs treatment group was significantly higher than that in the newly diagnosed group(P=0.033)(P=0.05).3.4.There was no significant difference in the relative content of NKT cells between the HMAs treatment group and the newly diagnosed group in patients with MDS.3.There was no significant difference between the HMAs treatment group and the non-HMAs treatment group and the control group in patients with AML and MDS(P=0.05).3.6.There was no significant difference in the relative content of NKT cells between the DAC treatment group and the AZA treatment group in patients with AML and MDS(P=0.539).3.7 there was no significant difference in the relative content of NKT cells in peripheral blood between HMAs treatment group and non-HMAs treatment group(remission group and non-remission group)in patients with AML and MDS.Conclusions:1.Tregs may be involved in the mechanism of tumor immune escape in patients with AML and MDS.HMAs may weaken the immune escape of tumor by rapidly consuming Tregs cells,and enhance the immune monitoring,recognition and killing of tumor cells by anti-tumor immune response.2.In atients with AML and MDS,the proportion of Thl/Th2 cells is out of balance.Thl and Th2 cells may be involved in the pathogenesis and progression of AML and MDS,while HMAs has no significant effect on the number of Thl and Th2 cells,so it is considered that it does not act on anti-tumor immune response through this pathway.3.NKT cells may be involved in the anti-tumor immune response of patients with AML and MDS.HMAs may promote the proliferation of NKT cells and enhance the anti-tumor immune response by weakening the tumor immune escape response or killing tumor cells.