Prothrombinase-induced clotting time assay for determination of the anticoagulant effects of unfractionated and low-molecular-weight heparins, fondaparinux, and thrombin inhibitors.
The prothrombinase-induced clotting time assay (PiCT, Pentapharm, Basel, Switzerland) is a clotting assay sensitive to factor Xa and factor IIa inhibitors. It is based on the addition of factor Xa and snake venom RVV-V (Russell viper venom factor V activator) specifically activating factor V and phospholipids to platelet-poor plasma. Following an incubation time, the mixture is recalcified and the clotting time is determined. An almost linear dose-response and high sensitivity of the assay for unfractionated heparin (UFH), low-molecular-weight heparins (LMWHs), r-hirudin, and argatroban was found. Fondaparinux showed a nonlinear dose-response. By using ex vivo samples, the following Pearson correlation coefficients were found: r=0.85 between amidolytic anti-Xa and PiCT for 120 LMWH and 24 control samples; r=0.86 between amidolytic anti-Xa activity and PiCT for 68 UFH and 24 control samples; and r=0.94 between ECT and PiCT for 38 hirudin samples. Thus, PiCT is a promising assay for the monitoring of anticoagulants inhibiting factor Xa and/or factor IIa.
Calatzis
Andreas
A
Department of Haemostasis and Transfusion Medicine, Munich University Clinic, Munich, Germany.
Peetz
Dirk
D
Haas
Sylvia
S
Spannagl
Michael
M
Rudin
Karin
K
Wilmer
Marianne
M
D001780:Blood Coagulation Tests / Q000379:methods*; D005343:Fibrinolytic Agents / Q000627:therapeutic use*; D000077425:Fondaparinux; D006493:Heparin / Q000627:therapeutic use*; D006495:Heparin, Low-Molecular-Weight / Q000627:therapeutic use*; D006801:Humans; D011134:Polysaccharides / Q000627:therapeutic use*; D012680:Sensitivity and Specificity; D013925:Thromboplastin / Q000502:physiology*
D005343:Fibrinolytic Agents; D006495:Heparin, Low-Molecular-Weight; D011134:Polysaccharides; D006493:Heparin; D013925:Thromboplastin; D000077425:Fondaparinux