35 - Flow Cytometry

Abstract

Flow cytometry is a remarkably versatile tool for the experimental and clinical study of platelet function, encompasses multiple assays for multiple purposes, and is particularly suited for analysis of platelet function in thrombocytopenic samples. Flow cytometry is used to: (a) measure the activation state of circulating platelets and their reactivity (by activation-dependent changes in platelet surface glycoproteins, leukocyte-platelet aggregation, procoagulant platelet-derived extracellular vesicles, and phosphorylation of intracellular proteins); (b) diagnose inherited (e.g., Bernard-Soulier syndrome, Glanzmann thrombasthenia) or acquired (e.g., heparin-induced thrombocytopenia (HIT)) disorders of platelet function; (c) monitor antiplatelet agents; (d) monitor thrombopoiesis (by the number of young, “reticulated” platelets); (e) perform assays relevant to blood banking (quality control of platelet concentrates, identification of leukocyte contamination in platelet concentrates, immunophenotyping of platelet HPA-1a, detection of maternal and fetal anti-HPA-1a antibodies, and platelet cross-matching); (f) measure platelet-associated IgG; (g) measure the platelet count; and (h) perform other research assays (measurement of platelet survival and function in vivo, F-actin content, calcium flux, fluorescence resonance energy transfer, platelet recruitment, and bacteria-platelet interactions). Recently there have been major technological advances in flow cytometry with the development of analytical tools such as mass cytometry and imaging flow cytometry. These platforms allow platelets to be studied in greater detail and give deeper insights into cellular function in health and disease.