Departments of Medicine and Biochemistry, The University of Vermont, Burlington, VT, USA.
Cardiovascular Research Institute, The University of Vermont, 308 S. Park Drive, Colchester, Burlington, VT, 05446, USA.
J Thromb Thrombolysis. 2019 Jul;48(1):88-94. doi: 10.1007/s11239-019-01852-7.
FcγRIIa amplifies platelet activation and greater platelet expression of FcγRIIa identifies patients at greater risk of subsequent cardiovascular events. Thus, platelet expression of FcγRIIa may be useful to guide therapy. Because platelet function tests are impacted by preparative procedures and substantial intra-individual variability, we examined the impact of these factors on platelet expression of FcγRIIa in blood from healthy subjects and in patients after myocardial infarction (MI). Platelet expression of FcγRIIa was quantified with the use of flow cytometry. Blood was taken from healthy subjects and 114 patients after a MI in whom platelet expression of FcγRIIa was quantified before discharge and at 6 ± 1 months. Neither anticoagulants nor the antiplatelet agent cangrelor changed platelet expression of FcγRIIa. Intra-individual variation in platelet FcγRIIa expression was 8.5% ± 5% over the course of 1 month in healthy subjects. Platelet FcγRIIa expression was within 20% of the baseline value after 6 months in 71% of patients after MI. In summary, because FcγRIIa is a protein on the surface of platelets, assay conditions and antiplatelet agents do not change expression. Intra-individual variability in platelet expression of FcγRIIa is modest. Accordingly, platelet expression of FcγRIIa is a marker of increased platelet reactivity that can be reliably and repeatedly measured.Clinical Trial Registration: NCT02505217.
FcγRIIa 增强血小板活化，FcγRIIa 在血小板上的表达增加可识别出随后发生心血管事件风险较高的患者。因此，FcγRIIa 在血小板上的表达可能有助于指导治疗。由于血小板功能检测受到制备程序和个体内较大变异性的影响，我们研究了这些因素对健康受试者和心肌梗死后患者血液中血小板 FcγRIIa 表达的影响。使用流式细胞术定量检测 FcγRIIa 在血小板上的表达。采集健康受试者和 114 名心肌梗死后患者的血液，在出院前和 6±1 个月时定量检测 FcγRIIa 在血小板上的表达。抗凝剂和抗血小板药物坎格雷洛均未改变 FcγRIIa 在血小板上的表达。在健康受试者中，1 个月内血小板 FcγRIIa 表达的个体内变异为 8.5%±5%。71%的心肌梗死后患者在 6 个月后 FcγRIIa 在血小板上的表达恢复至基线值的 20%以内。总之，由于 FcγRIIa 是血小板表面的一种蛋白质，因此测定条件和抗血小板药物不会改变其表达。血小板 FcγRIIa 表达的个体内变异性较小。因此，FcγRIIa 在血小板上的表达是血小板反应性增加的标志物，可进行可靠和重复的测量。临床试验注册：NCT02505217。
