Decreased Threshold of Aggregation to Low-Dose Epinephrine is Evidence of Platelet Hyperaggregability in Patients with Thrombosis

Sticky platelet syndrome has been described as a hereditary thrombophilic condition. The aim of this study is to identify the presence of platelet hyperaggregability in patients who have experienced thrombosis. Light-transmittance platelet aggregometry was used to assess for spontaneous platelet aggregation, aggregation in response to full and low-dose (LD) epinephrine (Epi) and adenosine diphosphate, as well as arachidonic acid, and identify a distinct pattern of platelet hyperaggregability. Light-transmittance platelet aggregometry results were correlated with PFA-100® (Dade-Behring, Marburg, Germany) results, when available. An exaggerated response to LD Epi was found in 68% of patients with thrombosis compared to only 36% of healthy controls (p = 0.034). Patients with thrombosis, either arterial or venous, demonstrated an exaggerated response to LD Epi nearly twice as frequently as healthy controls, even without significant family history of thrombophilia or other known risk factors for thrombosis. This suggests that platelet hyperaggregability may be multifactorial in nature and not necessarily hereditary.