Elevated anti-human factor Xa activity in rabbit and rodent plasma: Implications for preclinical assessment of human factor X in animal models of hemostasis

Thrombosis Research, vol. 198, pp. 154–162

Abstract

A wide variety of animal models on thrombosis and hemostasis are used in thrombosis and hemostasis research for the preclinical assessment of hemostatic agents. While the vertebrate coagulome is highly conserved, human and animal plasmas differ considerably when evaluated in coagulation assays such as prothrombin time (PT), activated partial thromboplastin time (APTT), and calibrated automated thrombography (CAT). Here, we have aimed to provide a reference framework for the evaluation of coagulation assays and inhibition of activated human FXa (hFXa) in various animal plasmas. To do so, a side-by-side evaluation of the extrinsic and intrinsic pathway of coagulation was performed by means of PT, APTT, and CAT measurements on (diluted) pooled plasmas from goats, pigs, rabbits, rats, mice, and humans. Plasma anti-FXa activity was assessed by determining the rate of recombinant hFXa inhibition through chromogenic activity analyses and immunoblotting. In general, rabbit, rat, and mouse plasmas exhibited robust clotting upon stimulation of both the extrinsic and intrinsic pathway, produced more thrombin during CAT upon plasma dilution, and displayed relatively high hFXa inhibitory activities. By comparison, goat, porcine, and human plasma displayed a similar profile in PT and APTT assays, produced less thrombin during CAT upon plasma dilution, and displayed comparable hFXa inhibitory activities. In conclusion, the observed differences in clotting parameters and anti-hFXa activity point to a higher anticoagulant threshold in plasma from rabbits, rats, and particularly in mice relative to human, goat, and porcine plasma. Finally, rat plasma was found to be more relevant to the preclinical assessment of human FX(a) in comparison to murine plasma.

Authors 5

1. Daniël Verhoef Aachen Department of Internal Medicine Division of Thrombosis and Hemostasis Einthoven Laboratory for Vascular and Regenerative Medicine

   Leiden University · Leiden University Medical Center

   Affiliation as printed

   Department of Internal Medicine, Division of Thrombosis and Hemostasis, Einthoven Laboratory for Vascular and Regenerative Medicine, Leiden University Medical Center, Leiden, the Netherlands; VarmX B.V., Leiden, the Netherlands

   Department of Internal Medicine, Division of Thrombosis and Hemostasis, Einthoven Laboratory for Vascular and Regenerative Medicine, Leiden University Medical Center, Leiden, the Netherlands

   VarmX B.V., Leiden, the Netherlands

2. Annabelle V.R. Tjalma Aachen Department of Internal Medicine Division of Thrombosis and Hemostasis Einthoven Laboratory for Vascular and Regenerative Medicine

   Leiden University · Leiden University Medical Center

   Affiliation as printed

   Department of Internal Medicine, Division of Thrombosis and Hemostasis, Einthoven Laboratory for Vascular and Regenerative Medicine, Leiden University Medical Center, Leiden, the Netherlands

3. Ka Lei Cheung Aachen Department of Internal Medicine Division of Thrombosis and Hemostasis Einthoven Laboratory for Vascular and Regenerative Medicine

   Leiden University · Leiden University Medical Center

   Affiliation as printed

   Department of Internal Medicine, Division of Thrombosis and Hemostasis, Einthoven Laboratory for Vascular and Regenerative Medicine, Leiden University Medical Center, Leiden, the Netherlands

4. Pieter H. Reitsma Aachen Department of Internal Medicine Division of Thrombosis and Hemostasis Einthoven Laboratory for Vascular and Regenerative Medicine

   Leiden University · Leiden University Medical Center

   Affiliation as printed

   Department of Internal Medicine, Division of Thrombosis and Hemostasis, Einthoven Laboratory for Vascular and Regenerative Medicine, Leiden University Medical Center, Leiden, the Netherlands; VarmX B.V., Leiden, the Netherlands

   Department of Internal Medicine, Division of Thrombosis and Hemostasis, Einthoven Laboratory for Vascular and Regenerative Medicine, Leiden University Medical Center, Leiden, the Netherlands

   VarmX B.V., Leiden, the Netherlands

5. Mettine H.A. Bos corresponding Aachen Department of Internal Medicine Division of Thrombosis and Hemostasis Einthoven Laboratory for Vascular and Regenerative Medicine

   Leiden University · Leiden University Medical Center

   Affiliation as printed

   Department of Internal Medicine, Division of Thrombosis and Hemostasis, Einthoven Laboratory for Vascular and Regenerative Medicine, Leiden University Medical Center, Leiden, the Netherlands. Electronic address: M.H.A.Bos@lumc.nl

   Department of Internal Medicine, Division of Thrombosis and Hemostasis, Einthoven Laboratory for Vascular and Regenerative Medicine, Leiden University Medical Center, Leiden, the Netherlands