BACKGROUND AND PURPOSE In order to assess the association of microparticles derived from activated platelets (PMP) or endothelial cells (EMP) with risk markers for recurrent embolic events in patients with symptomatic carotid artery disease, we studied the associations between PMP/EMP and three risk markers: plaque haemorrhage (PH), micro-embolic signals and cerebral diffusion abnormalities. METHODS Patients with recently symptomatic high-grade carotid artery stenosis (60-99%, 42 patients, 31 men; mean age 75 ± 8 years) and 30 healthy volunteers (HV, 11 men; mean age 56 ± 12 years) were prospectively recruited. Patients were characterised by carotid magnetic resonance imaging (presence of PH [MRI PH]), brain diffusion MRI (cerebral ischaemia [DWI+]) and transcranial Doppler ultrasound (micro-embolic signals [MES+]). PMP and EMP were classified by flow cytometry and expressed as log-transformed counts per microlitre. RESULTS MES+ patients (n = 18) had elevated PMP (MES+ 9.61 ± 0.57) compared to HV (8.80 ± 0.73; p < 0.0001) and to MES- patients (8.55 ± 0.85; p < 0.0001). Stroke patients had elevated PMP (9.49 ± 0.64) and EMP (6.13 ± 1.0) compared to non-stroke patients (PMP 8.81 ± 0.73, p = 0.026, EMP 5.52 ± 0.65, p = 0.011) and HV (PMP 8.80 ± 0.73, p = 0.007, and EMP 5.44 ± 0.47, p = 0.006). DWI+ patients (n = 16) showed elevated PMP (DWI+ 9.53 ± 0.64; vs. HV, p = 0.002) and EMP (DWI+ 5.91 ± 0.99 vs. HV 5.44 ± 0.47; p = 0.037). Only PMP but not EMP were higher in DWI+ versus DWI- patients (8.67 ± 0.90; p = 0.002). No association was found between PMP and EMP with MRI PH. CONCLUSIONS PMP and EMP were associated with stroke and recent cerebrovascular events (DWI+) but only PMP were also associated with ongoing (MES+) thrombo-embolic activity suggesting a differential biomarker potential for EMP to index cerebral ischaemia while PMP may predict on-going thrombo-embolic activity.

中文翻译：

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有症状的颈动脉疾病患者中的循环微粒与栓塞斑块活动和近期的脑缺血有关。

背景和目的为了评估在症状性颈动脉疾病患者中复发性栓塞事件的危险因素与活化血小板（PMP）或内皮细胞（EMP）衍生的微粒之间的关系，我们研究了PMP / EMP与三种危险因素之间的关系标记：斑块出血（PH），微栓塞信号和脑扩散异常。方法前瞻性招募了近期有症状的高级别颈动脉狭窄患者（60-99％，42例，31男性；平均年龄75±8岁）和30名健康志愿者（HV，11男性；平均年龄56±12岁）。 。患者的特征在于颈动脉磁共振成像（存在PH [MRI PH]），脑扩散MRI（脑缺血[DWI +]）和经颅多普勒超声（微栓塞信号[MES +]）。通过流式细胞仪对PMP和EMP进行分类，并表示为每微升对数转换计数。结果与HV（8.80±0.73; p <0.0001）和MES​​-患者（8.55±0.85; p <0.0001）相比，MES +患者（n = 18）的PMP升高（MES + 9.61±0.57）。与非中风患者相比（PMP 8.81±0.73，p = 0.026，EMP 5.52±0.65，p = 0.011）和HV（PMP 8.80±0.73，PMP（9.49±0.64）和EMP（6.13±1.0） p = 0.007，EMP为5.44±0.47，p = 0.006）。DWI +患者（n = 16）显示PMP（DWI + 9.53±0.64; vs HV，p = 0.002）和EMP（DWI + 5.91±0.99 vs. HV 5.44±0.47; p = 0.037）升高。DWI +患者中仅PMP而非EMP高于DWI-患者（8.67±0.90; p = 0.002）。MRI PH未发现PMP和EMP之间存在关联。