title: The purification step is not crucial in EIA measurements of thromboxane B2 and 11-dehydrothromboxane B2 in human plasma.
abstract: BACKGROUND
  Thromboxane B2 (TxB2) and particularly 11-dehydrothromboxane B2 (11-dTxB2) are widely used as prognostic risk markers of platelet activation in cardiovascular diseases. The main errors in TxB2 and 11-dTxB2 determination include either low concentrations of circulating TxB2 (1 - 2 pg/mL) and 11-dTxB2 (0.9 - 4.3 pg/mL) or rather high transiency (mean TxB2 half-life is approximately 5 minutes) as well as an incorrect pre-analytical phase set up. The aim of this study was to investigate the impact of a widely used purification step on the results of enzyme immunosorbent assay (EIA)--based measurement of the two selected thromboxanes.
  
  
  METHODS
  For the purpose of this study, 20 plasma samples (10 healthy donors, 10 patients under treatment with acetylsalicylic acid) were screened for TxB2 and 11-dTxB2 concentrations using commercial competitive EIA kits (Cayman Chemicals, Tallinn, Estonia; Neogen, Lexington, KY, USA) with or without the introduction of the purification procedure.
  
  
  RESULTS
  The purification step does not significantly affect the results of EIA measurements of the two of TxA2 metabolites (TxB2, 11-dTxB2) in human plasma. The levels of TxB2 and 11-dTxB2 determined in the plasma samples were not significantly changed (p < 0.05) when the purification step was omitted compared to the purified samples.
  
  
  CONCLUSIONS
  This study establishes a protocol allowing for reliable and reproducible plasma TxB2 and 11-dTxB2 EIA measurement for routine basic screening of platelet function.
authors.affiliation: Division of Clinical Pharmacology, Department of Medicine I, Thomayer University Hospital, Prague, Czech Republic. sadilkova@biomed.cas.cz
authors.forename: Lenka
authors.initials: L
authors.lastname: Sadilkova
authors.forename: Zoltan
authors.initials: Z
authors.lastname: Paluch
authors.forename: Jirina
authors.initials: J
authors.lastname: Mottlova
authors.forename: Frantisek
authors.initials: F
authors.lastname: Bednar
authors.forename: Stefan
authors.initials: S
authors.lastname: Alusik
mesh_terms: D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology; D001241:Aspirin / Q000494:pharmacology; D001792:Blood Platelets / Q000187:drug effects; D002318:Cardiovascular Diseases / Q000097:blood / Q000175:diagnosis; D006801:Humans; D007124:Immunoenzyme Techniques / Q000379:methods*; D015539:Platelet Activation / Q000187:drug effects; D011379:Prognosis; D011933:Reagent Kits, Diagnostic; D015203:Reproducibility of Results; D052616:Solid Phase Extraction / Q000379:methods*; D013929:Thromboxane B2 / Q000031:analogs & derivatives* / Q000097:blood
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D011933:Reagent Kits, Diagnostic; D013929:Thromboxane B2; C049235:11-dehydro-thromboxane B2; D001241:Aspirin