Abstract TMP26: Existence of Neutrophil Extracellular Traps in Arterial Thrombi from Patients with Acute Ischemic Stroke

Stroke ◽  
2017 ◽  
Vol 48 (suppl_1) ◽  
Author(s):  
Wei Li ◽  
Huan Wang ◽  
Wuwei Feng ◽  
Meng Zhang
Keyword(s):  
Electron Microscopy ◽  
Ischemic Stroke ◽  
Acute Ischemic Stroke ◽  
White Blood Cells ◽  
Neutrophil Extracellular Traps ◽  
Immunofluorescence Staining ◽  
Large Artery ◽  
Extracellular Traps ◽  
Arterial Thrombus ◽  
Hematoxylin Eosin

Introduction: Neutrophil extracellular traps (NETs) are composed mainly of strands of filamentous DNA and nuclear proteins, such as chromatin or isoforms of histone and secretable neutrophil granular proteins. Recent studies have shown that NETs existed in the venous thrombi and might function as a scaffold and had implication for thrombolytic treatments. Hypothesis: NETs also exists in cerebral arterial thrombus collected from patients with acute ischemic stroke(AIS). Methods: Ten arterial thrombi were collected from 10 AIS patients (33-78 years old, 4 females) who were treated by endovascular therapy (eight of them accepted alteplase thrombolysis firstly)within 8 hours after symptoms onset. Hematoxylin-eosin (HE) staining, immunofluorescence staining (including anti-histone H3 and Hoechst 33342 which label DNA) and electron microscopy were performed to identify the existence of fibrin and/or NETs in thrombus. Results: There were 4 thrombi from middle cerebral artery, 3 from internal carotid artery and 3 from basilar artery. Cardioembolism were considered as etiology for 5 patients and large artery atherosclerosis was the etiology for another 5 patients. HE staining showed that large amounts of fibrin and white blood cells in all ten cerebral arterial thrombi. NETs structures were also identified in 10/10 cerebral arterial thrombi by immunofluorescence staining. Furthermore, the existence of neutrophil-released DNA network together with fibrin was confirmed using electron microscopy in all 10 thrombi. Conclusion: Our results directly demonstrated that NETs do exist in the arterial thrombi from patients with AIS. they may serve as another structural component in addition to fibrin in both cardiogenic and artery atherosclerotic thrombi. NETs can be a new potential target for the recanalization treatment. Keyword: Neutrophil extracellular traps (NETs); arterial thrombus; Acute ischemic stroke

Correlation of Neutrophil to Lymphocyte Ratio with Expression of Neutrophil Extracellular Traps Within Stroke Emboli

2021 ◽  
pp. 159101992110655
Author(s):  
Jorge Arturo Larco ◽  
Mehdi Abbasi ◽  
Sarosh Irfan Madhani ◽  
Madalina Oana Mereuta ◽  
Yang Liu ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Acute Ischemic Stroke ◽  
Blood Cells ◽  
White Blood Cells ◽  
Neutrophil Extracellular Traps ◽  
Vessel Occlusion ◽  
Average Percentage ◽  
Neutrophil Lymphocyte Ratio ◽  
Lymphocyte Ratio ◽  
Extracellular Traps

Background & Purpose It has been hypothesized that circulating neutrophils have a direct correlation with the composition of emboli in acute ischemic stroke (AIS). The aim of this study is to evaluate the association between neutrophil-lymphocyte ratio (NLR) in peripheral blood and the expression of neutrophil extracellular traps (NETs) within stroke emboli. Methods Consecutive patients with acute ischemic stroke (AIS) due to large vessel occlusion (LVO) that underwent mechanical thrombectomy (MT) were included. Patients were divided into two groups based on NLR median value. Retrieved thrombi were histologically analyzed using Martius Scarlett Blue (MSB) for main thrombus components including red blood cells (RBCs), white blood cells (WBCs), fibrin and platelet. Immunohistochemistry staining for von Willebrand Factor (vWF) and anti-citrullinated H3 (H3Cit; NETs marker) was also performed. Results Samples from a total of 84 patients were included. The average percentage of RBCs, WBCs, fibrin, platelet, H3Cit, and vWF components in thrombi were 45.1%, 3.5%, 21.8%, 29.6%, 19.7% and 14.8% respectively. When stratifying by NLR group [low (≤3.94) versus high (>3.95)], high NLR group had significantly more WBCs (4.5%), fibrin (24.2%), H3Cit (22.7%) and vWF (17.1%) thrombus fractions compared to low NLR group. Additionally, RBC content (38.8%) was lower in the high NLR group. Conclusions NLR is correlated with the amounts of WBCs, fibrin, NETs and vWF within the thrombi retrieved from AIS patients due to LVO.

scholarly journals Thrombus Neutrophil Extracellular Traps Content Impair tPA-Induced Thrombolysis in Acute Ischemic Stroke

Stroke ◽  
2018 ◽  
Vol 49 (3) ◽  
pp. 754-757 ◽  
Author(s):  
Celina Ducroux ◽  
Lucas Di Meglio ◽  
Stephane Loyau ◽  
Sandrine Delbosc ◽  
William Boisseau ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Acute Ischemic Stroke ◽  
Neutrophil Extracellular Traps ◽  
Extracellular Traps

Neutrophil extracellular traps are increased in patients with acute ischemic stroke: prognostic significance

2017 ◽  
Vol 117 (10) ◽  
pp. 1919-1929 ◽  
Author(s):  
Juana Vallés ◽  
María Teresa Santos ◽  
Ana María Latorre ◽  
José Tembl ◽  
Juan Salom ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Acute Ischemic Stroke ◽  
Proteolytic Enzymes ◽  
Demographic Data ◽  
Prognostic Significance ◽  
Neutrophil Extracellular Traps ◽  
Stroke Severity ◽  
Specific Marker ◽  
Glucose Levels ◽  
Extracellular Traps

SummaryNeutrophil extracellular traps (NETs) are networks of DNA, histones, and proteolytic enzymes produced by activated neutrophils through different mechanisms. NET formation is promoted by activated platelets and can in turn activate platelets, thus favoring thrombotic processes. NETs have been detected in venous and arterial thrombosis, but data in stroke are scarce. The aim of this study was to evaluate NETs in the plasma of patients with acute ischemic stroke and their potential association with baseline clinical characteristics, stroke severity, and one-year clinical outcomes. The study included 243 patients with acute ischemic stroke. Clinical and demographic data and scores of stroke severity (NIHSS and mRs) at onset and discharge were recorded. Markers of NETs (cell-free DNA, nucleosomes, and citrullinated histone 3 (citH3)), were determined in plasma. Patients were followed-up for 12 months after the ischemic event. NETs were significantly elevated in the plasma of patients with acute ischemic stroke when compared to healthy subjects. NETs were increased in patients who were over 65 years of age and in those with a history of atrial fibrillation (AF), cardioembolic stroke, high glucose levels, and severe stroke scores at admission and discharge. In multivariate analysis, elevated levels of citH3, the most specific marker of NETs, at onset were independently associated with AF and all-cause mortality at oneyear follow-up. NETs play a role in the pathophysiology of stroke and are associated with severity and mortality. In conclusion, citH3 may constitute a useful prognostic marker and therapeutic target in patients with acute stroke.

Abstract TP214: 3D-Electron Microscopy for the Analysis of the Microstructure of Acute Ischemic Stroke Clots

Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Seán Fitzgerald ◽  
Daying Dai ◽  
Asim Rizvi ◽  
Karen M Doyle ◽  
Ramanathan Kadirvel ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Ischemic Stroke ◽  
Red Blood Cells ◽  
Acute Ischemic Stroke ◽  
Mayo Clinic ◽  
Blood Cells ◽  
White Blood Cells ◽  
Three Dimensional ◽  
3D Electron Microscopy

Introduction: Characterization of acute ischemic stroke thrombi has typically focused on the two dimensional (2D) histological characterization of the thrombus. Little is known about the three dimensional (3D) structure of these occlusive thrombi. Electron Microscopy (EM) can be used to obtain 3D information about the organization of clot components. Individual structures can be segmented and qualitative and quantitative information obtained from the clots. Methods: Following IRB approval from Mayo Clinic, acute ischemic stroke clot samples were collected from 10 patients treated at Mayo Clinic. Samples were immediately fixed in fresh modified Trumps fixative solution. A representative fragment of clot was taken and split longitudinally into two pieces; one piece was sent for 3D-EM analysis and the other for histological processing and analysis. Hematoxylin and eosin stain (H&E) and Martius Scarlett Blue (MSB) histological stains were used for conventional histopathology evaluation and components analysis. Immunohistochemical (IHC) staining using anti-CD42b (Platelets) was applied to confirm the presence of platelets in each clot. Serial block-face scanning electron microscopy was used to generate high-resolution three-dimensional images. Results: The 2D morphological features of the clot were identified using H&E, MSB and anti-CD42b staining. The 3D organization of thrombi varies greatly, both within and between clots depending on the constituents. Red Blood Cell-rich areas are mainly composed of Red Blood Cells packaged tightly together, with a small number of Fibrin strands interwoven between the cells. Fibrin-rich areas are characterized by dense networks of fibrin strands along with platelets and White Blood Cells with some sparse Red Blood Cells present. Platelet-rich areas are composed of large volumes of de-granulated platelets, some fibrin stands and white blood cells and an absence of Red Blood Cells. Conclusions: 3D electron microscopy can provide important information on the organization of components within thrombi. This could provide key information on the age and etiology of the thrombus. In addition, it may help to inform thrombolytic treatment and medical device design.

scholarly journals Immunohistological Analysis of Neutrophils and Neutrophil Extracellular Traps in Human Thrombemboli Causing Acute Ischemic Stroke

2020 ◽  
Vol 21 (19) ◽  
pp. 7387
Author(s):  
Fabian Essig ◽  
Alexander M. Kollikowski ◽  
Mirko Pham ◽  
László Solymosi ◽  
Guido Stoll ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Acute Ischemic Stroke ◽  
Plaque Rupture ◽  
Cerebral Arteries ◽  
Structural Complexity ◽  
Intravenous Thrombolysis ◽  
Neutrophil Extracellular Traps ◽  
Border Region ◽  
Imaging Data ◽  
Extracellular Traps

Ischemic stroke caused by thromboembolic occlusion of large cerebral arteries, such as the internal carotid (ICA) and/or the middle cerebral artery (MCA), is treated by mechanical thrombectomy (MT). MT allows salvage of the vessel-occluding thrombemboli, which most frequently originate from the left atrium or the left ventricle of the heart or from sites of plaque rupture within large arteries above the heart. Clot composition may influence the efficacy of (intravenous) thrombolysis and MT, respectively. We analyzed 37 human thrombemboli obtained from acute ischemic stroke patients during MT with special emphasis on histological staining of neutrophils and neutrophil extracellular traps (NETs). We found neutrophils as the main cellular component of cerebral thrombemboli but encountered considerable morphological heterogeneity. Neutrophils accumulated in the border region of fibrin-rich structures indicating possible interaction of neutrophils with distinct structural thrombembolus components. Web-like NETs were found in 35 of 37 thrombemboli in varying amounts. NETs were almost exclusively found within fibrin-rich areas. Importantly, stroke etiology, age and present oral anticoagulation was associated with morphological patterns and the amount of neutrophils. Correlation of histological data and imaging data revealed that relative Hounsfield units of cerebral thrombemboli positively correlated with the amount of red blood cells. In summary, our results demonstrate that neutrophils and NETs are substantial constituents of cerebral thrombemboli and contribute to their structural complexity.

High-resolution scanning electron microscopy for the analysis of three-dimensional ultrastructure of clots in acute ischemic stroke

2020 ◽  
pp. neurintsurg-2020-016709
Author(s):  
Oana Madalina Mereuta ◽  
Seán Fitzgerald ◽  
Trace A Christensen ◽  
Adam L Jaspersen ◽  
Daying Dai ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Ischemic Stroke ◽  
Acute Ischemic Stroke ◽  
Blood Cells ◽  
White Blood Cells ◽  
Three Dimensional ◽  
Ultrastructural Organization ◽  
Thrombolytic Treatment ◽  
Scanning Electron

BackgroundCharacterization of acute ischemic stroke (AIS) clots has typically focused on two-dimensional histological analysis of the thrombus. The three-dimensional (3D) architecture and distribution of components within emboli have not been fully investigated. The aim of this study was to examine the composition and microstructure of AIS clots using histology and serial block-face scanning electron microscopy (SBFSEM).MethodsAs part of the multi-institutional STRIP registry, 10 consecutive AIS emboli were collected from 10 patients treated by mechanical thrombectomy. Histological and immunohistochemical analysis was performed to determine clot composition. SBFSEM was used to assess the ultrastructural organization of the clots and specific features of individual components.ResultsQuantification of Martius Scarlett Blue stain identified fibrin (44.4%) and red blood cells (RBCs, 32.6%) as the main components. Immunohistochemistry showed a mean platelet and von Willebrand factor content of 23.9% and 11.8%, respectively. The 3D organization of emboli varied greatly depending on the region analyzed. RBC-rich areas were composed mainly of tightly packed RBCs deformed into polyhedrocytes with scant fibrin fibers interwoven between cells. The regions with mixed composition showed thick fibrin fibers along with platelets, white blood cells and RBC clusters. Fibrin-rich areas contained dense fibrin masses with sparse RBC. In three cases, the fibrin formed a grid-like or a sponge-like pattern, likely due to thrombolytic treatment. Segmentation showed that fibrin fibers were thinner and less densely packed in these cases.Conclusions3D-SEM provides novel and potentially clinically relevant information on clot components and ultrastructure which may help to inform thrombolytic treatment and medical device design.

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