title: Comparison and stability of ADAMTS13 activity in therapeutic plasma products.
abstract: BACKGROUND
  The von Willebrand factor (VWF)-cleaving protease, ADAMTS13, is often deficient in cases of thrombotic thrombocytopenic purpura (TTP). The primary treatment of TTP is therapeutic plasma exchange (TPE) utilizing a variety of plasma products that help restore ADAMTS13 activity. However, multiple replacement products are available to choose from. Thawed plasma products have a variable refrigerated shelf life depending on the product type; stability of ADAMTS13 in thawed products stored at 1 to 6 degrees C has not been determined.
  
  
  METHODS
  ADAMTS13 activity was measured in three types of plasma products and cryoprecipitate. Fresh-frozen plasma (FFP) aliquots and cryoprecipitate-poor plasma (CPP) products were produced from 10 whole-blood (WB) donations. Twenty-four-hour plasma products were manufactured from 10 additional WB donations. ADAMTS13 activity in these products at time of thaw and after 5 days of storage at 1 to 6 degrees C was measured with a modified version of the FRETS-VWF73 fluorogenic assay. ADAMTS13 activity at time of thaw was measured in 10 units of cryoprecipitate and five related CPP products.
  
  
  RESULTS
  ADAMTS13 is present in similar amounts in FFP, CPP, and 24-hour plasma products. Storage at 1 to 6 degrees C for up to 5 days did not significantly diminish ADAMTS13 activity. The concentration of ADAMTS13 in cryoprecipitate was significantly higher than that observed in plasma products.
  
  
  CONCLUSIONS
  FFP, CPP, and 24-hour plasma products should be equally effective for ADAMTS13 restoration through TPE and should remain so for the duration of the shelf life of the thawed products.
authors.affiliation: Blood Banking Training Program, Medical Services, BloodCenter of Wisconsin, Milwaukee, Wisconsin 53201, USA.
authors.forename: Erik A
authors.initials: EA
authors.lastname: Scott
authors.forename: Kathleen E
authors.initials: KE
authors.lastname: Puca
authors.forename: Bradley C
authors.initials: BC
authors.lastname: Pietz
authors.forename: Brian K
authors.initials: BK
authors.lastname: Duchateau
authors.forename: Kenneth D
authors.initials: KD
authors.lastname: Friedman
mesh_terms: D051722:ADAM Proteins / Q000097:blood*; D000071120:ADAMTS13 Protein; D000328:Adult; D000368:Aged; D001782:Blood Donors; D001793:Blood Preservation; D001803:Blood Transfusion; D015925:Cryopreservation; D004355:Drug Stability; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010949:Plasma; D013997:Time Factors
chemical_list: D051722:ADAM Proteins; D000071120:ADAMTS13 Protein; C099604:ADAMTS13 protein, human