title: [The value of von Willebrand factor pro-peptide and ADAMTS13 in diagnosis of thrombotic thrombocytopenic purpura].
abstract: OBJECTIVE
  To evaluate the combined analysis of ADAMTS13 activity and von Willebrand factor (vWF) pro-peptide level in the diagnosis and treatment of thrombotic thrombocytopenic purpura (TTP).
  
  
  METHODS
  ADAMTS13 activity was measured by Fluorescenced substrate method (with Frets-vWF73), and vWF pro-peptide was measured by sandwich ELISA in 11 patients with idiopathic TTP, 5 patients with secondary TTP, 2 patients with transplantation associated TTP and 3 patients with suspected TTP. Plot each patient's data in the graph with coordinates of ADAMTS13/vWF pro-peptide. The plot was divided into 4 quadrants by 2 lines, one went through 10% in ADMATS13 axis, and the other went through 3 in vWF pro-peptide axis. Analyze the characteristics of points in different quadrants.
  
  
  RESULTS
  Mean ADAMTS13 activities of idiopathic, secondary, transplantation associated and suspected TTP were 6.90%, 3.88%, 13.2% and 19.46% respectively. Mean times of elevated vWF pro-peptide from normal plasma pool of idiopathic, secondary, transplantation associated and suspected TTP were 4.2, 3.2, 4.5 and 2.9 respectively. In ADAMTS13/vWF pro-peptide figure, 57.1% of patients with TTP were in quadrant III, IV, all patients with transplantation associated TTP were in quadrant II ,2 of 3 patients with suspected TTP were in quadrant I.
  
  
  CONCLUSIONS
  Combined analysis of ADAMTS13 and vWF pro-peptide may provide clues and advices in the diagnosis and treatment of TTP, especially for the suspected ones.
authors.affiliation: Department of Hematology, West China Hospital, Sichuan University, Chengdu 610041, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Ji
authors.forename: Ting
authors.initials: T
authors.lastname: Liu
authors.forename: Wen-tong
authors.initials: WT
authors.lastname: Meng
authors.forename: Zhong-pin
authors.initials: ZP
authors.lastname: Lu
mesh_terms: D051722:ADAM Proteins / Q000378:metabolism*; D000071120:ADAMTS13 Protein; D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011498:Protein Precursors / Q000097:blood*; D011697:Purpura, Thrombotic Thrombocytopenic / Q000097:blood / Q000175:diagnosis*; D055815:Young Adult; D014841:von Willebrand Factor
chemical_list: D011498:Protein Precursors; D014841:von Willebrand Factor; C067003:von Willebrand factor propolypeptide; D051722:ADAM Proteins; D000071120:ADAMTS13 Protein; C099604:ADAMTS13 protein, human