Platelets show a substantial role in the maintenance of vascular integrity when these cells after a rapid activation adhere to the vessel wall lesion, aggregate with other platelets and leukocytes resulting in an arterial thrombosis. Analysis of in vivo platelet activation at an early time point is crucial in the detection of developing thrombotic events. In addition, the forecast of future complications as well as the evaluation of the efficacy of anti- platelet medication are also essential in a large group of patients. Changes in the levels of platelet receptors or alteration in other surface properties due to intra- and extracellular responses to a stimulus can be measurable primarily by flow cytometry with specific antibodies via the assessment of classical and alternative platelet activation markers. Some of these biomarkers have been already used in routine laboratory settings in many cases, while others still stand in the phase of research applications. Deficiency in platelet receptors is also accessible with this technique for the diagnosis of certain bleeding disorders. We here describe the most important types of platelet activation markers, and give an overview how the levels of these markers are altered in different diseases.
Keywords: P-selectin; coated-platelets; flow cytometry; heparin-induced thrombocytopenia; heterotypic aggregates; microparticle.