[Effect of arsenic trioxide and daunorubicin on procoagulant activity of acute promyelocytic leukemia cells].

OBJECTIVE: To explore the effect of arsenic trioxide (ATO) and daunorubicin (DNR) on phosphatidylserine (PS) exposure and related procoagulant activity of acute promyelocytic leukemia (APL) cells. METHODS: Mononuclear cell and neutrophil isolated from whole blood of 12 healthy volunteers were used as control group while APL cells obtained from 12 newly diagnosed APL patients at First Affiliated Hospital, Harbin Medical University from March 2007 to February 2009 were used as experimental group. APL cells were treated with 1 µmol/L ATO and 1 µmol/L DNR for 24 h. PS exposure of APL cells were measured by flow cytometry and confocal microscopy. And the related procoagulant activity was detected by the assays of coagulation time and coagulation factor formation. Lactadherin was used as a probe for PS exposure and anticoagulant on the cells of 12 APL patients. RESULTS: ATO induced a decrease of PS exposure on APL cells by flow cytometry and no staining with lactadherin was observed under confocal microscopy. However, DNR induced the significantly elevated PS exposure and staining green with a rim pattern on membrane of APL cells was obtained. Coagulation time was (180 ± 25) s and (220 ± 41) s before and after treatment with ATO, respectively (P < 0.05). The formation of coagulation factors decreased after treatment with ATO (P < 0.05). While coagulation time was (180 ± 25) s and (80 ± 20) s before and after treatment with DNR, respectively (P < 0.05). The formation of coagulation factors increased after treatment with DNR (all P < 0.05). Lactadherin inhibited the procoagulant activities of DNR-treated APL cells (all P < 0.05). CONCLUSIONS: Procoagulant activity is positively correlated with the exposed PS of APL cells. ATO and DNR inhibited and enhanced procoagulant activity with decreased and increased PS exposure, respectively.

[Expression and procoagulant activity of phosphatidylserine on the normal blood cells].

OBJECTIVE: To investigate the expression and procoagulant activity of phosphatidylserine (PS) on the normal peripheral blood cells of adults. METHODS: Normal peripheral blood samples were collected from 10 healthy volunteers (5 ml from each volunteer), platelets, neutrophils, lymphocytes and erythrocytes were isolated. The expression and procoagulant activity of PS on normal blood cells were identified by flow cytometry, inhibition test with lactadherin as PS probe and coagulation anticoagulant, respectively. RESULTS: There was PS expression on a few normal blood cells (9.1%, 5.4%, 3.9% and 3.2% in platelets, neutrophils, lymphocytes and erythrocytes, respectively). The PS on these normal blood cells in vitro showed significant procoagulant activity. The plasma recalcification time was shortened by 47%, 36.5%, 25% and 12.5% by platelets, neutrophils, lymphocytes and erythrocytes, respectively; the formation of factor Xa (through both intrinsic and extrinsic pathways) and thrombin was also increased by 13% - 26% by platelets, neutrophils, lymphocytes and erythrocytes, respectively. CONCLUSION: The PS on normal blood cells in vivo may play a crucial role in the coagulation cascade.