- Last Update On : 2013-03-02
Platelet aggregation testing is useful in the evaluation of suspected hereditary and acquired disorders of platelet function. Activation of platelets causes them to change shape, secrete their intracellular granules, and aggregate with each other. Platelets normally contain two major types of granules – alpha and dense granules. These granules contain substances which promote hemostasis when secreted from platelets at the site of vascular injury. The alpha granules contain fibrinogen, factor V, and von Willebrand factor while the dense granules contain platelet factor 4, ADP, ATP, calcium and serotonin.
Abnormalities of platelet function may be hereditary or acquired. Hereditary platelet function disorders include rare defects of adhesion (Bernard Soulier syndrome), rare defects of aggregation (Glanzmann thrombasthenia), and more common defects of secretion (alpha or dense granule deficiency, aspirin-like defects, or other primary secretion defects).