PB1092 - Identification of amplifying pathways of thrombin generation in a novel mouse whole blood assay

Tuesday, June 27, 2023

18:30 – 19:30 ET

Room: Exhibition

Co-Author(s)

Jun Wan, PhD (he/him/his)

Research Associate
Cyrus Tang Hematology Center, Soochow University
Suzhou, Jiangsu, China (People's Republic)

Co-Author(s)

Pansakorn Tanratana, MD, PhD

Assistant Professor
Department of Pharmacology, Faculty of Science, Mahidol University
Bangkok, Krung Thep, Thailand
Mark Roest, PhD (he/him/his)

Clinical Director
Department of Platelet pathophysiology, Synapse Research Institute, Maastricht, the Netherlands
Maastricht, Limburg, Netherlands
AG

Andras Gruber

Co-founder
Aronora, Inc.
Portland, Oregon, United States
Rafal Pawlinski, PhD

Professor of Medicine
Division of Hematology and Blood Research Center, University of North Carolina at Chapel Hill
Chapel Hill, North Carolina, United States
Alisa S. Wolberg, PhD

Professor
Univerisity of North Carolina at Chapel Hill
Chapel Hill, North Carolina, United States
Nigel Mackman, PhD

Professor
Univerisity of North Carolina at Chapel Hill
Chapel Hill, North Carolina, United States

Presenting Author(s)

Steven P. Grover, PhD

Research Assistant Professor
Division of Hematology and Blood Research Center, University of North Carolina, Chapel Hill
Chapel Hill, North Carolina, United States

Background: A number of coagulation reactions have been identified that are thought to contribute to amplification of thrombin generation (TG). These reactions include tissue factor (TF)– factor (F)VIIa mediated activation of FIX and thrombin mediated activation of FXI. At present, the relative contribution of these reactions to TG in the complex milieu of whole blood (WB) is unclear.

Aims: to evaluate the contribution of amplifying coagulation reactions to mouse WB TG

Methods: A novel mouse calibrated whole blood TG assay was established. WB was collected from FXII, FXI and FIX deficient mice. TG was initiated in mouse WB or platelet poor plasma (PPP) using the intrinsic pathway trigger silica or the extrinsic pathway trigger TF.

Results: As expected, silica-initiated TG was significantly reduced in WB and PPP from FXII, FXI and FIX deficient mice compared to wildtype controls. No significant effect of FXII deficiency was observed when TG was initiated with a low dose of TF (0.05pM) in mouse PPP or WB. Importantly, TG was significantly reduced in FXI deficient WB, but not PPP, when initiated with a low dose of TF (0.05pM) (Figure 1). TG in both FIX deficient WB and PPP was significantly reduced when initiated with a low dose of TF but the phenotype was markedly more pronounced in WB compared to PPP (Figure 2). The presence of both platelets and RBCs were found to contribute to the observed increased sensitivity of WB to FXI and FIX deficiency.

Conclusion(s): Mouse WB TG is sensitive to the contribution of amplifying coagulation reactions with phenotypes consistent with the presence of TF–FVIIa mediated activation of FIX and thrombin mediated activation of FXI.