OBJECTIVETo analyze the subtype and functional biomarker expression changes of natural kill cells(NK) in peripheral blood of patients with myelodysplastic syndrome(MDS) and normal people, so as to evaluate the relationships between these changes and hematopoietic functions and to explore the role of NK cells in the pathogenesis of MDS.

METHODSThe quantity of NK cells and the expression of biomarkers(NKp30,NKp46,NKG2A) on NK cells were detected by flow cytometry in 35 MDS patients from 2015 to 2016 in our hospital and 34 normal controls. The correlation between these changes and hematopoietic functions, including the percentages of neutrophil(ANC), hemoglobin in peripheral blood and the hematopoietic function in bone marrow(CD34%) were evaluated.

RESULTSThe percentage and quantity of NK cells and CD56NK cells in MDS patients were significantly lower than those in normal controls(P<0.05); the percentage of CD56NK cells was higher than that in controls. The percentage of CD56NK cells in NK cells of MDS patients was significantly lower than that of controls; the percentage of CD56NK cells in NK cells of MDS patients was significantly higher than that of controls. The expression of NKp30 and NKp46 of MDS patients was significantly lower than that of controls. In MDS group, the percentage of NK cells and CD56NK cells of peripheral blood lymphocytes in high risk MDS group was significantly lower than that in low risk MDS group. The percentage of NK and CD56NK cells negatively correlated with that of CD34% in bone marrow, but positively correlated with ANC and Hb. The CD34% in bone marrow negatively correlated with expression of NKp46, but positively correlated with expression of NKG2A.

CONCLUSIONThe decrease of NK number and function may cause the immune surveillance and lead to disease progression.