Diagnosis: Platelet Function Testing: Vasodilator-Stimulated Phosphoprotein (VASP) Phosphorylation
• Platelet function studies have historically been used to investigate the cause of unexplained bleeding. Platelet function tests are also increasingly being used to monitor the therapeutic efficacy of antiplatelet agents used to treat patients at high risk for atherothrombosis.
• The basis of the vasodilator-stimulated phosphoprotein (VASP) phosphorylation assay is measurement of activation-dependent signaling by flow cytometry.
• It is a whole blood assay considered the gold standard for assessing the P2Y12 antagonist effect.
• Its major disadvantage is that it requires complex sample preparation, a flow cytometer (i.e., high capital investment), and a high level of technical experience.
• P2Y12 inhibitors used as antiplatelet agents include clopidogrel, prasugrel, cangrelor, and ticagrelor.
