OBJECTIVETo detect the plasma activity of von Willebrand factor-cleaving protease (ADAMTS13) in the patients with prothrombotic status, and explore the effect and significance of ADAMTS13 in the prothrombotic status. The correlation of ADAMTS13 with von Willebrand factor (vWF), thrombospondin 1 (TSP1), C-reactive protein etc, and blood pressure was simultaneously analyzed．

METHODSThe activity of ADAMTS13 in patient groups (atherosclerosis, diabetes, acute promyelocytic leukemia, cancer and sepsis, a total of 260 cases) and in control group 50 cases were evaluated by residue collagen binding assay（R-CBA）, the protein levels of TSP1 and vWF were measured by ELISA kits； the correlation of ADAMTS13 activity with CRP, creatinine, and blood pressure was analyzed with statistical soft ware.

RESULTSThe activity of plasma ADAMTS13 in patient group was significantly lower than that in normal control group(P<0.05). And the protein levels of TSP1 and vWF in the patients with prothrombotic status were higher than those in the normal controls(P<0.05). Analysis of the correlation showed that the ADAMTS13 activity correlated negatively with the levels of TSP1 protein, blood sugar, blood pressure, D-dimer, creatinine,and CRP levels (P<0.05), however, the ADAMTS13 activity did not significantly correlate with the levels of serum lipids, blood type, platelet number and hemoglobin level(P>0.05).

CONCLUSIONThe plasma ADAMTS13 activity is decreased in the patients with prothrombotic status, suggesting that the decreased ADAMTS13 activity may participate in the occurrence of prothrombotic status, and the dectection of plasma ADAMTS13 activity may help the diagnosis of pro-thrombotic disease.