OBJECTIVETo investigate the distribution of T helper (Th9) cells and its relationship with clinical characteristics of patients with acute myeloid leukemia (AML), and to analyze the activating levels of different transcriptional factors in Th9 cells.

METHODSThe peripheral blood specimens of 102 AML patients and 83 healthy persons as controls were collected, then the T cells of peripheral blood in AML patients and controls were isolated by using CD3 magnetic beads, the mRNA expression of IL-9 was detected by real-time quantitative PCR, the Th9(CD4IL-9) cell levels in diffrent stages and activating level of Th9 coexpression with IL-9 were detected by flow cytometry.

RESULTSThe mRNA expression of IL-9 in peripheral blood of AML M2 and M3 patients was significantly higher than that in control groups (P<0.01), at same time the CD4IL-9cell rate was significantly higher than that in control group also(P<0.01). The results of dynamically monitoring the distribution of Th9 cells in AML-M2 and M3 patients showed that the Th9 cell rate and the mRNA expression of IL-9 in newly diagnosed M2 and M3, and relapsed M2 groups were significantly higher than those of M2 and M3 in remission (P<0.01); the detection results of IL-9co-expression with transcriptional factors (SMAD3, IRF-1and IRF-4) indicated that the percantage of Th9 pSMAD3cells in peripheral blood of newly diagnosed and relapsed M2 and M3 patients was significantly higher than that in M2 and M3 patients in remission (P<0.01); on the contrary, the percentage of Th9 IRF-1cells in peripheral blood of M2 and M3 patients in remission was significantly higher than that in newly diagnosed M2 and M3 patients (P<0.01).

CONCLUSIONThe distribution of T helper cells in peripheral blood of AML-M2 and M3 patients significantly increases, moreover, correlates with disease status. The prediction of Th9 cell functions should be performed in combination with it transcriptional factors which have inmportant significance for microenvironment of tumors in AML patients.