Continuous thrombin generation in whole blood: New applications for assessing activators and inhibitors of coagulation

Abstract

Hemostatic tests have been utilized to clarify the blood coagulation potential. The novel thrombin generation (TG) assay of this study provides explicit information and is the most physiologically-relevant hemostatic test ex vivo. We describe how this assay allows for TG under a number of relevant circumstances. First, whole blood (WB) from healthy individuals was analyzed ± 5 pM tissue factor (TF) and ± contact pathway inhibition. Without an exogenous initiator TG was decreased and delayed, but addition of 5 pM TF shortened the lag phase and increased peak thrombin. Additional experiments included fresh WB from a trauma patient analyzed for endogenous activity and TG from healthy donors subjected to TG antagonists which prolonged the lag phase whereas TG agonists consistently shortened the lag phase in a dose dependent manner. Lastly, platelet-poor plasma was reconstituted with packed red blood cells and TG was monitored in the presence and absence of both TF as an activator and PCPS as a phospholipid surface. Our data illustrate the potential that this continuous TG assay has in the evaluation of disorders relevant to blood coagulation and in the monitoring of treatments administered in response to these disorders.

Andexanet versus prothrombin complex concentrates: Differences in reversal of factor Xa inhibitors in in vitro thrombin generation

“…used as a pharmacodynamic marker for restoration of hemostasis for hemophilia treatment and anticoagulation reversal, although plasma thrombin generation assays do not include cellular components of whole blood,34,35 and a correlation between restoration of thrombin generation and hemostasis has not been established in bleeding patients taking FXa inhibitors. In the present study, we used pooled human plasma and the same version of TF-TG assay as F I G U R E 3 Effect of andexanet on TF-TG (ETP) in the presence of rivaroxaban or apixaban compared with 4F-PCCs.…”

Effect of the expression of CD62P and thrombin generation on patients using central venous catheters for hemodialysis

“…Higher TG is characterized by decreased lagtime and increased ETP and peak values, indicating a state of hypercoagulability. 8,[12][13][14] The data obtained from TGTs using low or high concentrations of TF revealed that the peripheral blood samples obtained from patients after 4 months of CVC insertion had a higher potential for TG than the samples obtained from controls and patients with 1 month of CVC insertion (Table 1).…”

“…When platelet activation occurs, a greater amount of thrombin is generated during the amplification and propagation of the coagulation cascade, resulting in an exponential increase of thrombin . Thrombin is considered the key enzyme of the coagulation system.…”

“…When platelet activation occurs, a greater amount of thrombin is generated during the amplification and propagation of the coagulation cascade, resulting in an exponential increase of thrombin. [13][14][15][16][17] Thrombin is considered the key enzyme of the coagulation system. The thrombin generation test (TGT) has emerged as a tool capable of assessing global hemostasis in a more physiological manner than conventional tests.…”

“…The thrombin generation test (TGT) has emerged as a tool capable of assessing global hemostasis in a more physiological manner than conventional tests. [13][14][15][16][17] For this reason, TG testing with the calibrated automated thrombogram (CAT) method was used in the present study to evaluate the potential for TG in patients undergoing hemodialysis using CVCs.…”