title: Validation of human recombinant tissue factor-activated thromboelastography on citrated whole blood from clinically healthy dogs.
abstract: BACKGROUND
  Thromboelastography (TEG) is an analytical method that enables global assessment of hemostatic function in whole blood (WB) with evaluation of both plasma and cellular components of hemostasis. TEG has a largely unused potential in the diagnostic workup and monitoring of dogs with hemostatic disorders and it may be a valuable supplement to traditional coagulation parameters.
  
  
  OBJECTIVE
  The objective of this study was to establish a clinically applicable reference interval for a TEG assay using recombinant human tissue factor (TF) as the activator on citrated WB from clinically healthy dogs and to evaluate the stability of citrated WB stored for 30 minutes (T30) and 120 minutes (T120) at room temperature (RT). Additionally, we evaluated the analytical variation in reaction time (R), clotting time (K), angle (alpha), and maximum amplitude (MA).
  
  
  METHODS
  Blood was collected from 18 clinically healthy dogs. Duplicate TEG analyses with TF as the activator at a concentration of 1:50,000 were performed on canine citrated WB at T30 and T120. R, K, a, and MAwere analyzed.
  
  
  RESULTS
  Mean TEG values at T30/T120 were R = 5.61/4.91 minutes, K = 4.20/3.34 minutes, alpha = 45.33/50.90 degrees , and MA = 47.96/50.19 mm. Significant differences in these values were observed after storage for T30 and T120 at RT, with a tendency towards hypercoagulability at T120. The mean coefficients of variation were low.
  
  
  CONCLUSIONS
  Canine citrated WB can be used for TEG analysis with human recombinant TF as the activator when stored at RT for T30 or T120. At both time points, the analytical variation was low, suggesting that TEG analysis may be of value in evaluating dogs with hemostatic disorders. A fixed time point should be chosen for serial measurements.
authors.affiliation: Department of Small Animal Clinical Sciences, The Royal Veterinary and Agricultural University, Copenhagen, Denmark. bwi@kvl.dk
authors.forename: Bo
authors.initials: B
authors.lastname: Wiinberg
authors.forename: Asger Lundorff
authors.initials: AL
authors.lastname: Jensen
authors.forename: Rasmus
authors.initials: R
authors.lastname: Rojkjaer
authors.forename: Pär
authors.initials: P
authors.lastname: Johansson
authors.forename: Mads
authors.initials: M
authors.lastname: Kjelgaard-Hansen
authors.forename: Annemarie T
authors.initials: AT
authors.lastname: Kristensen
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001777:Blood Coagulation; D001780:Blood Coagulation Tests / Q000379:methods / Q000662:veterinary; D001793:Blood Preservation / Q000379:methods / Q000662:veterinary; D002951:Citrates; D004285:Dogs / Q000097:blood*; D005260:Female; D006487:Hemostasis; D006801:Humans; D008297:Male; D011994:Recombinant Proteins; D012015:Reference Standards; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013696:Temperature; D013916:Thrombelastography / Q000379:methods / Q000662:veterinary*; D013925:Thromboplastin; D013997:Time Factors
chemical_list: D002951:Citrates; D011994:Recombinant Proteins; D013925:Thromboplastin