Prothrombinase-Induced Clotting Time Assay for Determination of the Anticoagulant Effects of Unfractionated and Low-Molecular-Weight Heparins, Fondaparinux, and Thrombin Inhibitors

Abstract

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.

Determination of dabigatran in plasma, serum, and urine samples: comparison of six methods

“…In the prothrombinase-induced clotting time (PiCT) assay [27], Russell's viper venom activates factor V, and the prothrombinase formation only relies on the activity of factors X and II being sensitive toward all inhibitors of these clotting enzymes [28]. The PiCT assay was performed with the two-step method (reagents from Pentapharm, Basle, Switzerland), with a mean ± SD of 29.9 ± 4.6 s [29].…”

From laboratory to clinical practice: Dabigatran effects on thrombin generation and coagulation in patient samples

“…Modified PiCT® has been used to measure both DTIs and FXa inhibitors [15]. Russell's viper venom time (RVVT) with a FX-specific activator is sensitive to FXa inhibitors, but might also be useful to assess DTIs [16].…”

Monitoring of direct anticoagulants

“…Although the clot principle is applied in the specific composition of the reagent, ecarin clotting time (ECT) or prothrombinase induced clotting time (PICT) [12,18,19] allows to overcome most influences that can disturb the global assays like PT and APTT (Fig. 6).…”