Stephen J X Murphy1,2, Soon Tjin Lim1,2, Justin A Kinsella3, Sean Tierney4, Bridget Egan4, T M Feeley4,5, Sinead M Murphy1,6,7, Richard A Walsh1,7, D R Collins2,6, Tara Coughlan2,6, Desmond O'Neill2,6, Joseph A Harbison8, Prakash Madhavan9, Sean M O'Neill9, Mary P Colgan9, Dermot Cox10, Niamh Moran10, George Hamilton11, Dominick J H McCabe1,2,6,12,13,14. 1. Department of Neurology, Adelaide and Meath Hospital, Dublin, incorporating the National Children's Hospital (AMNCH)/Tallaght University Hospital, Dublin, Ireland. 2. Stroke Service, Adelaide and Meath Hospital, Dublin, incorporating the National Children's Hospital (AMNCH)/Tallaght University Hospital, Dublin, Ireland. 3. Department of Neurology, St Vincent's University Hospital, University College Dublin, Dublin, Ireland. 4. Department of Vascular Surgery, Adelaide and Meath Hospital, Dublin, incorporating the National Children's Hospital (AMNCH)/Tallaght University Hospital, Dublin, Ireland. 5. Dublin Midlands Hospital Group, Ireland. 6. Age-Related Health Care Department, Adelaide and Meath Hospital, Dublin, incorporating the National Children's Hospital (AMNCH)/Tallaght University Hospital, Dublin, Ireland. 7. Academic Unit of Neurology, School of Medicine, Trinity College Dublin, Ireland. 8. Department of Medicine for the Elderly/Stroke Service, St James Hospital/Trinity College Dublin, Ireland. 9. Department of Vascular Surgery, St James Hospital/Trinity College Dublin, Dublin, Ireland. 10. Department of Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland, Dublin, Ireland. 11. Department of Vascular Surgery, University Department of Surgery, Royal Free Hampstead NHS Trust, London, United Kingdom. 12. Vascular Neurology Research Foundation, c/o Department of Neurology, Adelaide and Meath Hospital, Dublin, incorporating the National Children's Hospital (AMNCH)/Tallaght University Hospital, Dublin, Ireland. 13. Department of Clinical Neurosciences, Royal Free Campus, UCL Institute of Neurology, London, United Kingdom. 14. Irish Centre for Vascular Biology, Dublin, Ireland.
Abstract
INTRODUCTION: Cerebral micro-embolic signals (MES) predict risk of stroke in carotid stenosis patients. However, MES-negative 'recently symptomatic patients' also have a higher stroke risk than 'asymptomatic patients'. Differences in platelet activation status may contribute to this disparity in risk. METHODS: This prospective, observational study assessed platelet biomarkers and their relationship with MES in asymptomatic versus symptomatic moderate (≥50-69%) or severe (≥70-99%) carotid stenosis patients. Full blood count parameters were measured and whole-blood flow cytometry was used to quantify platelet surface CD62P and CD63 expression and leucocyte-platelet complex formation. Bilateral simultaneous transcranial Doppler ultrasound of the middle cerebral arteries classified patients as 'MES positive' or 'MES negative'. RESULTS: Data from 34 asymptomatic patients were compared with those from 43 symptomatic patients in the 'early phase' (≤ 4 weeks) and 37 of these symptomatic patients in the 'late phase' (≥ 3 months) after transient ischaemic attack/ischaemic stroke. There were no differences in %CD62P or %CD63 expression between early or late symptomatic and asymptomatic patients overall (p > 0.05). The percentage of lymphocyte-platelet complexes was higher in early symptomatic than in asymptomatic patients (2.8 vs. 2.16%; p < 0.001). MES were more commonly observed in early symptomatic (31.4%; p = 0.027) but not in late symptomatic (6.7%; p = 0.996) versus asymptomatic patients (7.1%). The percentage of lymphocyte-platelet complexes was higher in early symptomatic than in asymptomatic MES-negative patients (2.7 vs. 2.17%; p = 0.02). CONCLUSION: These data add to the evidence that leucocyte-platelet complex formation/platelet activation is increased in recently symptomatic versus asymptomatic patients, and may contribute to the pathogenesis of first and subsequent strokes in carotid stenosis patients, including those who are MES negative. Georg Thieme Verlag KG Stuttgart · New York.
INTRODUCTION: Cerebral micro-embolic signals (MES) predict risk of stroke in carotid stenosispatients. However, MES-negative 'recently symptomatic patients' also have a higher stroke risk than 'asymptomatic patients'. Differences in platelet activation status may contribute to this disparity in risk. METHODS: This prospective, observational study assessed platelet biomarkers and their relationship with MES in asymptomatic versus symptomatic moderate (≥50-69%) or severe (≥70-99%) carotid stenosispatients. Full blood count parameters were measured and whole-blood flow cytometry was used to quantify platelet surface CD62P and CD63 expression and leucocyte-platelet complex formation. Bilateral simultaneous transcranial Doppler ultrasound of the middle cerebral arteries classified patients as 'MES positive' or 'MES negative'. RESULTS: Data from 34 asymptomatic patients were compared with those from 43 symptomatic patients in the 'early phase' (≤ 4 weeks) and 37 of these symptomatic patients in the 'late phase' (≥ 3 months) after transient ischaemic attack/ischaemic stroke. There were no differences in %CD62P or %CD63 expression between early or late symptomatic and asymptomatic patients overall (p > 0.05). The percentage of lymphocyte-platelet complexes was higher in early symptomatic than in asymptomatic patients (2.8 vs. 2.16%; p < 0.001). MES were more commonly observed in early symptomatic (31.4%; p = 0.027) but not in late symptomatic (6.7%; p = 0.996) versus asymptomatic patients (7.1%). The percentage of lymphocyte-platelet complexes was higher in early symptomatic than in asymptomatic MES-negative patients (2.7 vs. 2.17%; p = 0.02). CONCLUSION: These data add to the evidence that leucocyte-platelet complex formation/platelet activation is increased in recently symptomatic versus asymptomatic patients, and may contribute to the pathogenesis of first and subsequent strokes in carotid stenosispatients, including those who are MES negative. Georg Thieme Verlag KG Stuttgart · New York.
Authors: Stephen J Murphy; Soon T Lim; Justin A Kinsella; Sean Tierney; Bridget Egan; Tim M Feeley; Clare Dooley; James Kelly; Sinead M Murphy; Richard A Walsh; Ronan Collins; Tara Coughlan; Desmond O'Neill; Joseph A Harbison; Prakash Madhavan; Sean M O'Neill; Mary P Colgan; Jim F Meaney; George Hamilton; Dominick Jh McCabe Journal: J Cereb Blood Flow Metab Date: 2019-11-11 Impact factor: 6.200
Authors: S J X Murphy; S T Lim; J A Kinsella; S Tierney; B Egan; T M Feeley; S M Murphy; R A Walsh; D R Collins; T Coughlan; D O'Neill; J A Harbison; P Madhavan; S M O'Neill; M P Colgan; D Cox; N Moran; G Hamilton; J F Meaney; D J H McCabe Journal: J Neurol Date: 2019-10-12 Impact factor: 4.849
Authors: Stephen J X Murphy; Soon Tjin Lim; Fionnuala Hickey; Justin A Kinsella; Deirdre R Smith; Sean Tierney; Bridget Egan; T Martin Feeley; Sinéad M Murphy; D Rónán Collins; Tara Coughlan; Desmond O'Neill; Joseph A Harbison; Prakash Madhavan; Sean M O'Neill; Mary-Paula Colgan; James S O'Donnell; Jamie M O'Sullivan; George Hamilton; Dominick J H McCabe Journal: Thromb Haemost Date: 2020-09-15 Impact factor: 5.249