Alteration of circulating endothelial cells from acute promyelocytic leukemia patients before and after treatment and its influential factors

AIM: To determine the biological feature of circulating endothelial cells (CECs) in acute promyelocytic leukemia (APL) patients before and after treatment, and to analyze the relationship between CECs and the clinical characteristics. METHODS: The CECs were sorted from peripheral blood by magnetic-activated cell sorting and then counted by 3-color flow cytometry. The cells were identified by immunofluorescence staining for the expression of CD146, CD31, CD144, VEGFR-2, CD45 and CD133. The CECs were cultured in vitro, and the tube formation and colony-forming rate were determined. RESULTS: Increased quantity of CECs was observed in CD34 positive group and group with WBC>10×10⁹/L (P<0.05). The quantity of CECs had a significant difference among low risk, medium risk and high risk groups (P<0.05). The positive rate of CD133 and quantity of CECs significantly reduced in 32 APL patients when they gain complete remission after treatment (P<0.05). The amount of tube formation and colony-forming rate were significantly reduced after treatment (P<0.05). The ratio of CECs quantity from APL patients after treatment to that before treatment had a negative correlation with arsenic concentration in urine on day 7 during As₂O₃ treatment (P<0.05). CONCLUSION: Accurately counting CECs may be helpful for evaluating prognosis and designing treatment strategy.