[The Expression and Function of NK Cells in Patients with Acute Myeloid Leukemia].

ABSTRACT

OBJECTIVE: To explore the expression characteristics of antigens and functional markers of natural killer (NK) cells in patients with acute myeloid leukemia (AML). METHODS: Multi-parameter flow cytometry was used to detect NK cell surface markers and their functional indicators in 56 newly diagnosed AML patients and 24 healthy controls, including activating receptors NKG2D, NKP46, DNAM-1, and killing indicators granzyme B, perforin. RESULTS: Referring to the WHO hematopoiesis and lymph tissue tumor classification criteria, 56 cases were roughly divided into three types AML M1, M2, and M4/M5. However, there was no differences about NK cells among the three types, so it was no longer subdivided. NK cells were divided into two groups CD3-CD56hiCD16- (CD56hiNK) and CD3-CD56dimCD16+ (CD56dimNK). Compared with CD56dimNK cell population, except for NKP46, the positive expression levels of NKG2D and other receptors of CD56hiNK cells in AML patients decreased (P<0.001). Compared with healthy controls, the proportion of CD56hiNK cells in AML patients increased, while the number and proportion of NK cells and proportion of CD56dimNK cells significantly decreased (P<0.05). The proportion of perforin in CD56hiNK cells significantly increased (P<0.05). The expression of DNAM-1 in CD56hiNK cells, NKG2D, DNAM-1, and perforin in CD56dimNK cells decreased significantly (P<0.05). There was no statistically significant difference in expression of other functional indexes in AML patients compared with corresponding indexes of healthy controls. In addition, the proportion of CD56hiNK cells was positively correlated with the expression of CD34+ in AML (r=0.303). CONCLUSION: Compared with CD56dimNK, the ratio of CD56hiNK and the expression of functional markers in AML patients are lower. Compared with healthy controls, the number and expression ratio of NK cells in AML patients decrease and the expression of functional markers is abnormal, indicating that its function is impaired.