Assessment of platelet function: Laboratory and point-of-care methods

Table 2 Advantages and disadvantages of different platelet function methodologies

Platelet tests	Advantages	Disadvantages
Bleeding time	Physiological In vivo test Easy, quick No WB processing	Operator dependent Invasive Poorly standardized Dependent on different variables (skin thickness, t°C)
Light transmission platelet aggregation in PRP	Historical gold standard Flexible Diagnostic method Different agonists available Sensitive for anti-plt therapy	Pre- and analytic variables Time-consuming High sample volume Sample preparation
WB Impedance Platelet Aggregometry	No sample preparation Flexible Diagnostic method Different agonists available Sensitive for anti-plt therapy Close to POCT (Multiple system)	Limited HCT and platelet count range
Flow Cytometry	Small blood volumes Diagnosis ex vivo of platelet activation Evaluation of efficacy of thienopyridyne therapy	Expensive Specialized equipment Experienced operator Careful sample processing Probable, possible artifacts
Platelet Function Analyzer -PFA-100 /Innovance PFA-200	In vitro standardized BT POCT Easy, quick Sensitive to severe platelet dysfunctions	Nonflexible Platelet count- HCT-dependent Not sensitivity for platelet secretion defects.
VerifyNow system	POCT WB assay Easy, quick No WB processing	Expensive Nonflexible Monitoring antiplatelet therapy only Limited HCT and platelet count
Impact Cone and Plate(let) analyzer	WB assay Global platelet function Small sample volume	Expensive Experienced staff Lacking of clinical studies Not widely available
Plateletworks	POC WB system Minimal sample preparation Easy, rapid screening test	Indirect assay Required platelet count method Not so well studied
Viscoelastic methods	POCT Global hemostasis test Anticoagulation monitoring Predicts bleeding Reduces blood transfusions Improve clinical outcome	Measure clot properties Depend on: platelet function, coagulation and fibrinolysis factors More studies are needed

HCT: Hematocrit; plt: Platelet; POCT: Point-of-Care Testing; PRP: Platelet-rich-plasma; WB: Whole blood.