The TGA is a global test of coagulation systems, with the potential to contribute to the current arsenal of clinical prognostication and drug monitoring tools. By varying the conditions under which it is applied, the test can be made sensitive…
Laboratory testing modalities and recommendations for monitoring heparin, heparin-like medications, direct thrombin inhibitors (DTIs), and direct anti-Xa inhibitors (DXIs), including indications, testing recommendations, testing modalities, and test limitations are discussed below. There are several options available for laboratory monitoring of…
Protein S (PS) is a vitamin K–dependent plasma glycoprotein that serves as a cofactor of activated protein C (APC). When bound to APC, it accelerates protein C–dependent degradation of factor (F) Va and FVIIIa. PS deficiency is inherited in an…
Protein C (PC) is a vitamin K–dependent, heterodimeric, plasma glycoprotein that is synthesized as a zymogen in the liver. It is activated on the endothelial surface by the thrombin–thrombomodulin (TM) complex. Once produced, the activated protein C (APC) cleaves and…
Congenital antithrombin (AT) deficiency occurs in 0.2%–0.02% of the general population. However, in patients who had suffered a venous thromboembolic event (VTE), the prevalence is approximately 1%–3%. Preanalytical variables must be taken into account when deciding on the timing of…
Abnormal thrombosis is a result of a pathologic shift in the balance between antihemorrhagic (prothrombotic) and antithrombotic factors toward conditions that favor thrombus formation at the wrong time and/or in the wrong location. The Virchow triad of blood stasis, inflammation,…
FXIII is a hemostatic protein that plays a critical role in stabilizing fibrin networks at the site of injury and thus preventing premature fibrinolysis. In the plasma, FXIII circulates as a tetrameric zymogen composed of two catalytic alpha chains (FXIII-A)…
Antiplatelet medications are widely used to treat or prevent thrombosis in a variety of cardiovascular disorders. Currently available antiplatelet drugs comprise four categories: 1. Acetylsalicylic acid (aspirin) inhibits cyclooxygenase (COX-1), 2. P2Y12 receptor antagonists (clopidogrel, ticlopidine, prasugrel, cangrelor, ticagrelor) block…
Recent years have seen a significant increase in the utilization of rotational viscoelectric global hemostasis testing in point-of-care settings in support of complicated surgical procedures and trauma. The current instruments allow near real-time data gathering, with many results being available…
Numerical platelet determination is a critical step in assessing bleeding and thrombosis risk. Additionally, platelet count serves as a biomarker for a number of pathologic states. Modern automated hematology analyzers produce fast, accurate, and precise platelet determination under most circumstances.…