Determination of ADAMTS13 Antigen and Activity Levels in Patients with Acute Myocardial Infarction and Acute Ischemic Stroke.

von Willebrand factor-cleaving protease (ADMTS13) is a metalloproteases regulating von Willebrand factor multimers size in plasma, its activity decrease has been reported in many physiological and pathological conditions. But information on ADAMTS13 in arterial thrombosis disease and in the general population is limited. In this study, we investigated the ADAMTS13 antigen and activity levels in 87 healthy control subjects of different ages, in 93 patients with acute myocardial infarction (AMI) and in 30 patients with acute ischemic stroke (AIS). ADAMTS13 Antigen levels were measured using a sandwich ELISA, and ADAMTS13 activity levels were analyzed by the FRETS-VWF73 method. A pool of plasma obtained from 40 blood donors was used as reference and was defined to contain 100% of the protease. The individual subject of the pool was not included in the study. Compared with 50 sex- and age-matched control subjects, ADAMTS13 antigen and activity levels were significantly lower in patients with arterial thrombosis diseases. Antigen levels were 87.8±19.8%, 61.8±18.8%, and 70.2±15.5% respectively in control, AMI and ASI patients. ADAMTS13 activity were 81.7±13.9%, 59.2±22.1% and 65.4±15.8% respectively. In the 87 healthy subjects, the range of ADAMTS13 activity is from 46.3% to 119.0%, and antigen is from 60.8% to 141.9%. In different age groups (17 to 20 years old, 21 to 40 years old, 41 to 60 years old, and older than 60 years old), ADAMTS13 antigen levels were 76.0%, 109.7%, 99.3%, and 74.5% respectively, and activity levels were 80.8%, 81.1%, 77.9%, and 87.3% respectively. It seems the antigen reached the highest level in people from 21 to 40 years old, then gradually decreased with age. The antigen and activity mean in males (87.1% and 80.8%) was lower than that in females (94.7% and 86.1%), but the difference is not significant (p=0.145 and p=0.124). In conclusion, the decrease of ADAMTS13 antigen and activity in AMI and AIS patients indicated ADMATS13 might contribute to arterial thrombosis, and the plasma ADAMTS13 antigen level in the general population was significantly affected by age.