Changes of ADAMTS13 activity and vWF antigen level in patients with acute myelogenous leukemia and their significance

This study was purposed to investigate the changes of von Willebrand factor cleaving protease (ADAMTS13) activity and vWF antigen level in patients with acute myelogenous leukemia (AML) before and after treatment and evaluate their clinical significance. Seventy-three AML patients were enrolled in this study, the sodium citrate anticoagulated plasma was collected before and after their induction chemotherapy. Fluorescence resonance energy transfer substrate vWF73 (FRETS-vWF73) assay was established to detect the plasma ADAMTS13 activity while vWF antigen level was measured by ELISA. The results showed that the ADAMTS13 activity in newly diagnosed patients with AML before induction therapy was obviously lower than that in normal controls (63.3 ± 25.5)% vs (105.1 ± 37.7)(P < 0.01), while the vWF antigen level was higher than that in normal controls (226.6 ± 127.0)% vs (111.4 ± 39.7)% (P < 0.01). After standard induction chemotherapy, the ADAMTS13 activity of AML patients in complete remission period was higher than that in AML patients before therapy (P < 0.01), and was not significant difference with that in normal controls; the vWF antigen was significantly lower than that in AML patients before therapy (P < 0.01), but it still was higher than that in controls (P < 0.05). The ADAMTS13 activity in newly diagnosed AML patients complicated with infection before therapy was obviously lower than that in AML patients without infection (52.2 ± 20.6)% vs (73.9 ± 24.7)% (P < 0.01), while the vWF antigen level was significantly higher than that in AML patients without infection (262.2 ± 135.7)% vs (193.8 ± 110.2)% (P < 0.05). The ADAMTS13 activity in AML patients with disseminated intravascular coagulation (DIC) was significantly lower than that in AML patients without DIC (42.0 ± 14.5)% vs (73.4 ± 22.7)% (P < 0.01), while the vWF antigen level was obviously higher that in AML patients without DIC (274.2 ± 140.0)% vs (204.7 ± 115.5)% (P < 0.01). It is concluded that the ADAMTS13 activity in newly diagnosed AML patients befor induction therapy has been confiremed to be lower and the vWF antigen level to be higher, especially in AML patients with infection or DIC. The ADAMTS13 and vWF antigen may play a role in the pathogenesis of AML and the formation of infection and DIC.