Clinical Pathology: Hematology & Coagulation

• Platelet function studies have historically been used to investigate the cause of unexplained bleeding. The majority of platelet-related bleeding can be attributed to defects of primary hemostasis, such as von Willebrand disease, inherited platelet disorders, and drug-induced platelet dysfunction.

• Platelet function tests are also increasingly used to monitor the therapeutic efficacy of antiplatelet agents used to treat patients at high risk for atherothrombosis.

• The basis of using thromboelastography to evaluate platelet function is to evaluate the contribution of platelets to clot strength in a whole blood samples.

• Advantages of thromboelastography: It measures global coagulation (i.e., clotting factors, platelets, fibrinolysis) and can potentially be used at the point of care (e.g., in the operating room).

• Disadvantages of thromboelastography: To test the platelet-specific contribution to clot formation and strength, additional platelet activators (arachidonic acid or adenosine diphosphate [ADP]) must be used, thereby increasing the complexity of the test.

Rechner AR: Platelet function testing in clinical diagnostics. Hamostaseologie 2011;31:79–87.

Favaloro EJ, et al: Contemporary platelet function testing. Clin Chem Lab Med 2010;48:579–598.

Michelson AD: Platelet function testing in cardiovascular diseases. Circulation 2004;110:e489–e493.

 
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