Department of Neurology, The Adelaide and Meath Hospital, Dublin, incorporating the National Children's Hospital (AMNCH), Dublin, Ireland.
Stroke Service, The Adelaide and Meath Hospital, Dublin, incorporating the National Children's Hospital (AMNCH), Dublin, Ireland.
J Neurol. 2018 May;265(5):1037-1049. doi: 10.1007/s00415-018-8797-8. Epub 2018 Feb 23.
The pathophysiological mechanisms responsible for the disparity in stroke risk between asymptomatic and symptomatic carotid stenosis patients are not fully understood. The functionally important reticulated platelet fraction and reticulocytes could play a role.
We performed a prospective, multi-centre, observational analytical study comparing full blood count parameters and platelet production/turnover/activation markers in patients with asymptomatic versus recently symptomatic moderate (≥ 50-69%) or severe (≥ 70-99%) carotid stenosis.
PATIENTS/METHODS: Data from 34 asymptomatic patients were compared with 43 symptomatic patients in the 'early phase' (≤ 4 weeks) and 37 of these patients in the 'late phase' (≥ 3 months) after TIA/ischaemic stroke. Reticulated platelets were quantified by whole blood flow cytometry and reticulated platelets and red cell reticulocytes by 'automated assays' (Sysmex XE-2100™). Bilateral simultaneous transcranial Doppler ultrasound monitoring classified patients as micro-embolic signal (MES)+ve or MES-ve.
Mean platelet count was higher in early (216 × 10/L; P = 0.04) and late symptomatic (219 × 10/L; P = 0.044) than asymptomatic patients (194 × 10/L). Mean platelet volume was higher in early symptomatic than asymptomatic patients (10.8 vs. 10.45 fl; P = 0.045). Automated assays revealed higher % reticulated platelet fractions in early (5.78%; P < 0.001) and late symptomatic (5.11%; P = 0.01) than asymptomatic patients (3.48%). Red cell reticulocyte counts were lower in early (0.92%; P = 0.035) and late symptomatic (0.93%; P = 0.036) than asymptomatic patients (1.07%). The automated % reticulated platelet fraction was also higher in early symptomatic than asymptomatic MES-ve patients (5.7 vs. 3.55%; P = 0.001).
The combination of increased platelet counts and a shift towards production of an increased population of larger, young, reticulated platelets could contribute to a higher risk of first or recurrent cerebrovascular events in recently symptomatic versus asymptomatic carotid stenosis, including those who are MES-ve.
无症状和有症状颈动脉狭窄患者中风风险差异的病理生理机制尚不完全清楚。功能重要的网织血小板和网织红细胞可能发挥作用。
我们进行了一项前瞻性、多中心、观察性分析研究，比较了无症状患者与近期有症状（狭窄程度≥50-69%）或严重（狭窄程度≥70-99%）颈动脉狭窄患者的全血细胞参数和血小板生成/周转/激活标志物。
患者/方法：将 34 例无症状患者的数据与症状性患者（早期，≤4 周）43 例和这些患者中的 37 例（晚期，≥3 个月）进行比较。使用全血流式细胞术定量检测网织血小板，使用“自动化检测”（Sysmex XE-2100™）定量检测网织血小板和红细胞网织红细胞。双侧同步经颅多普勒超声监测将患者分为微栓子信号（MES）+阳性或 MES-阴性。
早期（216×10/L；P=0.04）和晚期（219×10/L；P=0.044）有症状患者的平均血小板计数高于无症状患者（194×10/L）。早期有症状患者的平均血小板体积高于无症状患者（10.8 vs. 10.45 fl；P=0.045）。自动化检测显示，早期（5.78%；P<0.001）和晚期（5.11%；P=0.01）有症状患者的网织血小板比例高于无症状患者（3.48%）。早期（0.92%；P=0.035）和晚期（0.93%；P=0.036）有症状患者的红细胞网织红细胞计数低于无症状患者（1.07%）。早期有症状且 MES-阴性患者的自动化网织血小板比例也高于无症状患者（5.7 vs. 3.55%；P=0.001）。
血小板计数增加和更大、更年轻的网织血小板生成比例增加的组合可能导致近期有症状的颈动脉狭窄患者，包括 MES-阴性患者发生首次或复发性脑血管事件的风险增加。
