Name: Author Spotlight: Deciphering Coagulation Disorders in Traumatic Brain Injury Patients
Uploaded: 2023-08-04T13:40:00
Description: Watch this Scientific Journal Video about Deciphering Coagulation Disorders in Traumatic Brain Injury Patients at JoVE.com

This work was supported by grants from the National Natural Science Foundation of China, grant no. 81930031, 81901525. In addition, we thank Tianjin Century Yikang Medical Technology Development Co., Ltd. for providing us with machines and technical guidance.

The collection of human samples was approved by the Medical Ethics Committee of Tianjin Medical University General Hospital. The collection of human venous blood strictly followed the guideline issued by the National Health Commission of China, namely WS/T 661-2020 Guideline for Collection of Venous Blood Specimens. Briefly, blood was collected from healthy individuals with informed consent from the anterior brachial area vein, and the samples were mixed using 3.2% sodium citrate anticoagulant in a ratio of 1:9. When onl...

Assessing Blood Hypercoagulation of EV-Rich Plasma

<ol>
	<li>Zhang, J., Zhang, F., Dong, J. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Coagulopathy+induced+by+traumatic+brain+injury:+systemic+manifestation+of+a+localized+injury.">Coagulopathy induced by traumatic brain injury: systemic manifestation of a localized injury.</a> Blood. 131 (18), 2001-2006 (2018).</li><li>Han, C., Chen, Y. Y., Dong, J. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Prothrombotic+state+associated+with+preeclampsia.">Prothrombotic state associated with preeclampsia.</a> Current Opinion in Hematology. 28 (5), 323-330 (2021).</li><li>Campello, E., Bosch, F., Simion, C., Spiezia, L., Simioni, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechanisms+of+thrombosis+in+pancreatic+ductal+adenocarcinoma.">Mechanisms of thrombosis in pancreatic ductal adenocarcinoma.</a> Best Practice &amp; Research Clinical Haematology. 35 (1), 101346 (2022).</li><li>You, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Identification+of+hypercoagulability+with+thrombelastography+in+patients+with+hip+fracture+receiving+thromboprophylaxis.">Identification of hypercoagulability with thrombelastography in patients with hip fracture receiving thromboprophylaxis.</a> Canadian Journal of Surgery. 64 (3), E324-E329 (2021).</li><li>Shah, R., Patel, T., Freedman, J. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Circulating+extracellular+vesicles+in+human+disease.">Circulating extracellular vesicles in human disease.</a> The New England Journal of Medicine. 379 (10), 958-966 (2018).</li><li>Zang, X., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hepatocyte-derived+microparticles+as+novel+biomarkers+for+the+diagnosis+of+deep+venous+thrombosis+in+trauma+patients.">Hepatocyte-derived microparticles as novel biomarkers for the diagnosis of deep venous thrombosis in trauma patients.</a> Clinical and Applied Thrombosis/Hemostasis. 29, 10760296231153400 (2023).</li><li>Chen, Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Annexin+V(-)+and+tissue+factor(+)+microparticles+as+biomarkers+for+predicting+deep+vein+thrombosis+in+patients+after+joint+arthroplasty.">Annexin V(-) and tissue factor(+) microparticles as biomarkers for predicting deep vein thrombosis in patients after joint arthroplasty.</a> Clinica Chimica Acta. 536, 169-179 (2022).</li><li>Wang, C., Yu, C., Novakovic, V. A., Xie, R., Shi, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Circulating+microparticles+in+the+pathogenesis+and+early+anticoagulation+of+thrombosis+in+COVID-19+with+kidney+injury.">Circulating microparticles in the pathogenesis and early anticoagulation of thrombosis in COVID-19 with kidney injury.</a> Frontiers in Cell and Developmental Biology. 9, 784505 (2021).</li><li>Lacroix, R., Dubois, C., Leroyer, A. S., Sabatier, F., Dignat-George, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Revisited+role+of+microparticles+in+arterial+and+venous+thrombosis.">Revisited role of microparticles in arterial and venous thrombosis.</a> Journal of Thrombosis and Haemostasis. 11 (Suppl 1), 24-35 (2013).</li><li>Cointe, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Standardization+of+microparticle+enumeration+across+different+flow+cytometry+platforms:+results+of+a+multicenter+collaborative+workshop.">Standardization of microparticle enumeration across different flow cytometry platforms: results of a multicenter collaborative workshop.</a> Journal of Thrombosis and Haemostasis. 15 (1), 187-193 (2017).</li><li>Ayers, L., Harrison, P., Kohler, M., Ferry, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Procoagulant+and+platelet-derived+microvesicle+absolute+counts+determined+by+flow+cytometry+correlates+with+a+measurement+of+their+functional+capacity.">Procoagulant and platelet-derived microvesicle absolute counts determined by flow cytometry correlates with a measurement of their functional capacity.</a> Journal of Extracellular Vesicles. 3, 25348 (2014).</li><li>Mooberry, M. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Procoagulant+microparticles+promote+coagulation+in+a+factor+XI-dependent+manner+in+human+endotoxemia.">Procoagulant microparticles promote coagulation in a factor XI-dependent manner in human endotoxemia.</a> Journal of Thrombosis and Haemostasis. 14 (5), 1031-1042 (2016).</li><li>Zhao, Z., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cellular+microparticles+and+pathophysiology+of+traumatic+brain+injury.">Cellular microparticles and pathophysiology of traumatic brain injury.</a> Protein &amp; Cell. 8 (11), 801-810 (2017).</li><li>Bolliger, D., Tanaka, K. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Point-of-care+coagulation+testing+in+cardiac+surgery.">Point-of-care coagulation testing in cardiac surgery.</a> Seminars in Thrombosis and Hemostasis. 43 (4), 386-396 (2017).</li><li>Ganter, M. T., Hofer, C. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Coagulation+monitoring:+current+techniques+and+clinical+use+of+viscoelastic+point-of-care+coagulation+devices.">Coagulation monitoring: current techniques and clinical use of viscoelastic point-of-care coagulation devices.</a> Anesthesia &amp; Analgesia. 106 (5), 1366-1375 (2008).</li><li>Samuelson, B. T., Cuker, A., Siegal, D. M., Crowther, M., Garcia, D. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Laboratory+assessment+of+the+anticoagulant+activity+of+direct+oral+anticoagulants:+a+systematic+review.">Laboratory assessment of the anticoagulant activity of direct oral anticoagulants: a systematic review.</a> Chest. 151 (1), 127-138 (2017).</li><li>Maier, C. L., Sniecinski, R. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Anticoagulation+monitoring+for+perioperative+physicians.">Anticoagulation monitoring for perioperative physicians.</a> Anesthesiology. 135 (4), 738-748 (2021).</li><li>Tuktamyshov, R., Zhdanov, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+method+of+in+vivo+evaluation+of+hemostasis:+Spatial+thrombodynamics.">The method of in vivo evaluation of hemostasis: Spatial thrombodynamics.</a> Hematology. 20 (10), 584-586 (2015).</li><li>Tsantes, A. G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Higher+coagulation+activity+in+hip+fracture+patients:+A+case-control+study+using+rotational+thromboelastometry.">Higher coagulation activity in hip fracture patients: A case-control study using rotational thromboelastometry.</a> International Journal of Laboratory Hematology. 43 (3), 477-484 (2021).</li><li>Premkumar, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=COVID-19-related+dynamic+coagulation+disturbances+and+anticoagulation+strategies+using+conventional+D-dimer+and+point-of-care+Sonoclot+tests:+a+prospective+cohort+study.">COVID-19-related dynamic coagulation disturbances and anticoagulation strategies using conventional D-dimer and point-of-care Sonoclot tests: a prospective cohort study.</a> BMJ Open. 12 (5), e051971 (2022).</li><li>Sakai, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparison+between+thromboelastography+and+thromboelastometry.">Comparison between thromboelastography and thromboelastometry.</a> Minerva Anestesiologica. 85 (12), 1346-1356 (2019).</li><li>Yan, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=TMEM16F+mediated+phosphatidylserine+exposure+and+microparticle+release+on+erythrocyte+contribute+to+hypercoagulable+state+in+hyperuricemia.">TMEM16F mediated phosphatidylserine exposure and microparticle release on erythrocyte contribute to hypercoagulable state in hyperuricemia.</a> Blood Cells, Molecules and Diseases. 96, 102666 (2022).</li><li>Yu, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hyperuricemia+enhances+procoagulant+activity+of+vascular+endothelial+cells+through+TMEM16F+regulated+phosphatidylserine+exposure+and+microparticle+release.">Hyperuricemia enhances procoagulant activity of vascular endothelial cells through TMEM16F regulated phosphatidylserine exposure and microparticle release.</a> The FASEB Journal. 35 (9), e21808 (2021).</li><li>Gao, Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=MPs-ACT,+an+assay+to+evaluate+the+procoagulant+activity+of+microparticles.">MPs-ACT, an assay to evaluate the procoagulant activity of microparticles.</a> Clinical and Applied Thrombosis/Hemostasis. 29, 10760296231159374 (2023).</li><li>Wang, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Brain-derived+extracellular+vesicles+induce+vasoconstriction+and+reduce+cerebral+blood+flow+in+mice.">Brain-derived extracellular vesicles induce vasoconstriction and reduce cerebral blood flow in mice.</a> Journal of Neurotrauma. 39 (11-12), 879-890 (2022).</li><li>Tan, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Analysis+of+circulating+microvesicles+levels+and+effects+of+associated+factors+in+elderly+patients+with+obstructive+sleep+apnea.">Analysis of circulating microvesicles levels and effects of associated factors in elderly patients with obstructive sleep apnea.</a> Frontiers in Aging Neuroscience. 13, 609282 (2021).</li><li>Kubo, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Extracellular+vesicles+in+lung+disease.">Extracellular vesicles in lung disease.</a> Chest. 153 (1), 210-216 (2018).</li><li>Gilani, S. I., Weissgerber, T. L., Garovic, V. D., Jayachandran, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Preeclampsia+and+Extracellular+Vesicles.">Preeclampsia and Extracellular Vesicles.</a> Current Hypertension Reports. 18 (9), 68 (2016).</li><li>Pourakbari, R., Khodadadi, M., Aghebati-Maleki, A., Aghebati-Maleki, L., Yousefi, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+potential+of+exosomes+in+the+therapy+of+the+cartilage+and+bone+complications;+emphasis+on+osteoarthritis.">The potential of exosomes in the therapy of the cartilage and bone complications; emphasis on osteoarthritis.</a> Life Science. 236, 116861 (2019).</li><li>Shi, J., Gilbert, G. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lactadherin+inhibits+enzyme+complexes+of+blood+coagulation+by+competing+for+phospholipid-binding+sites.">Lactadherin inhibits enzyme complexes of blood coagulation by competing for phospholipid-binding sites.</a> Blood. 101 (7), 2628-2636 (2003).</li><li>Dasgupta, S. K., Le, A., Chavakis, T., Rumbaut, R. E., Thiagarajan, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Developmental+endothelial+locus-1+(Del-1)+mediates+clearance+of+platelet+microparticles+by+the+endothelium.">Developmental endothelial locus-1 (Del-1) mediates clearance of platelet microparticles by the endothelium.</a> Circulation. 125 (13), 1664-1672 (2012).</li><li>Frey, B., Gaipl, U. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+immune+functions+of+phosphatidylserine+in+membranes+of+dying+cells+and+microvesicles.">The immune functions of phosphatidylserine in membranes of dying cells and microvesicles.</a> Seminars in Immunopathology. 33 (5), 497-516 (2011).</li><li>Rikkert, L. G., Coumans, F. A. W., Hau, C. M., Terstappen, L., Nieuwland, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Platelet+removal+by+single-step+centrifugation.">Platelet removal by single-step centrifugation.</a> Platelets. 32 (4), 440-443 (2021).</li><li>Chen, Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Association+of+placenta-derived+extracellular+vesicles+with+pre-eclampsia+and+associated+hypercoagulability:+a+clinical+observational+study.">Association of placenta-derived extracellular vesicles with pre-eclampsia and associated hypercoagulability: a clinical observational study.</a> BJOG. 128 (6), 1037-1046 (2021).</li><li>Liu, Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+potential+applications+of+microparticles+in+the+diagnosis,+treatment,+and+prognosis+of+lung+cancer.">The potential applications of microparticles in the diagnosis, treatment, and prognosis of lung cancer.</a> Journal of Translational Medicine. 20 (1), 404 (2022).</li><li>Piwkham, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+in+vitro+red+blood+cell+microvesiculation+exerts+procoagulant+activity+of+blood+cell+storage+in+Southeast+Asian+ovalocytosis.">The in vitro red blood cell microvesiculation exerts procoagulant activity of blood cell storage in Southeast Asian ovalocytosis.</a> Heliyon. 9 (1), e12714 (2023).</li><li>Patil, R., Ghosh, K., Shetty, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+simple+clot+based+assay+for+detection+of+procoagulant+cell-derived+microparticles.">A simple clot based assay for detection of procoagulant cell-derived microparticles.</a> Clinical Chemistry and Laboratory Medicine. 54 (5), 799-803 (2016).</li></ol>

In this study, the preparation of EV-rich plasma was described, and the method&#39;s rationality was verified using flow cytometry. Subsequently, the recalcified plasma samples were analyzed for ACT time using a clot analyzer based on viscoelasticity principles24. As shown in Figure 3A, the concentration of EVs obtained through ultracentrifugation was found to shorten the EV-ACT time, while the supernatant after ultracentrifugation, which had reduced EV levels, exhibi...

Thrombosis, which is caused by hypercoagulability, plays a significant role in various diseases, including brain trauma1, pre-eclampsia2, tumors3, and fracture patients4. The mechanism underlying hypercoagulability is complex, and recent emphasis has been placed on the role of extracellular vesicles (EV) in coagulation disorders. EVs are vesicle-like bodies with a bilayer structure that detach from the cell membrane, ranging in diameter from 10 nm to 1000 nm. They are associated with a variety of disease processes, particularly coagulation disorders5. Several studies have identified EVs as a promising predictor of thrombosis risk6,7. The procoagulant activity of EVs depends on the expression of coagulation factors, primarily tissue factor (TF) and phosphatidylserine (PS). EVs with robust procoagulant activity significantly enhance the catalytic efficiency of tenase and prothrombin complex, thereby promoting thrombin-mediated fibrinogen and local thrombosis8. Elevated levels of EVs and their causal relationship with hypercoagulability have been observed in numerous diseases9. Consequently, standardizing the detection of EVs and reporting their procoagulant activity is an important area of investigation10.
To date, only a few commercial kits are available for detecting the procoagulant activity of EVs. The MP-Activity assay and the MP-TF assay, produced by a commercial company, are functional assays used to measure EV&#39;s procoagulant activity in plasma11. These assays employ a principle similar to that of enzyme-linked immunosorbent assays to detect PS and TF on EVs. However, these kits are expensive and limited to a few high-level research institutions. The process is complex and time-consuming, making it challenging to implement them in clinical settings. Additionally, a commercially developed procoagulant phospholipid (PPL) assay mixes PS-free plasma with test plasma, measuring clotting time to quantitatively detect levels of PS-positive EVs12. However, these assays primarily focus on PS and TF on EVs, overlooking other clotting pathways that circulating EVs may be involved in12.
The plasma coagulation system is intricate and comprises both &#34;invisible&#34; and &#34;visible&#34; components, including coagulants, anticoagulants, fibrinolytic systems, and EVs suspended in the plasma. Physiologically, these components maintain a dynamic balance. In pathological conditions, significantly increased EVs in circulation contribute to hypercoagulability, particularly in patients with brain trauma, preeclampsia, fractures, and various types of cancer13. Currently, the evaluation of coagulation status in clinical laboratories primarily involves assessing the coagulation system, anticoagulation system, and fibrinolysis14,15,16,17. Prothrombin time, activated partial thromboplastin time, thrombin time, and international normalized ratio are commonly used to evaluate coagulation factor levels in the coagulation system18. However, recent studies have revealed that these tests do not fully reflect the hypercoagulability of certain diseases19. Other assay methods, such as thromboelastometry (TEG), rotational TEG, and Sonoclot analysis, measure whole-blood viscoelastic changes20,21. Since whole blood samples contain numerous blood cells and platelets, these tests are more likely to indicate the clotting status of the sample as a whole. Some researchers have reported on the role of blood cells and platelets in procoagulant activity22,23. A recent study also discovered that previous coagulation function tests face difficulties in detecting changes in microparticles&#39; procoagulant activity24. Therefore, a hypothesis has been proposed that the procoagulant function of EVs can be evaluated by viscoelastic measurements of the activated clotting time (ACT) in EV-rich plasma.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>AccuCount Ultra Rainbow Fluorescent Particles</td>
			<td>3.8 microm; Spherotech, Lake Forest, IL, USA</td>
			<td></td>
			<td>For quantitative detection of MP</td>
		</tr>
		<tr>
			<td>Calcium chloride</td>
			<td>Werfen (china)</td>
			<td>0020006800</td>
			<td>20 mM</td>
		</tr>
		<tr>
			<td>Century Clot analyzer</td>
			<td>Tianjin Century Yikang Medical Technology Development Co., Ltd</td>
			<td></td>
			<td>The principle is to measure plasma viscosity by viscoelastic method</td>
		</tr>
		<tr>
			<td>Disposable probe and test cup</td>
			<td>Tianjin Century Yikang Medical Technology Development Co., Ltd</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>LSR Fortessa flow cytometer</td>
			<td>BD, USA</td>
			<td></td>
			<td>Used to detect MP</td>
		</tr>
		<tr>
			<td>Megamix polystyrene beads</td>
			<td>Biocytex, Marseille, France</td>
			<td>7801</td>
			<td>The Megamix consists of a mixture of microbeads of selected diameters: 0.5 &#181;m, 0.9 &#181;m and 3 &#181;m.</td>
		</tr>
	</tbody>
</table>

determination of the procoagulant activity of extracellular vesicle (ev) using ev-activated clotting time (ev-act)

The role of extracellular vesicles (EV) in various diseases is gaining increased attention, particularly due to their potent procoagulant activity. However, there is an urgent need for a bedside test to assess the procoagulant activity of EV in clinical settings. This study proposes the use of thrombin activation time of EV-rich plasma as a measure of EV's procoagulant activity. Standardized procedures were employed to obtain sodium-citrated whole blood, followed by differential centrifugation to obtain EV-rich plasma. The EV-rich plasma and calcium chloride were added to the test cup, and the changes in viscoelasticity were monitored in real-time using an analyzer. The natural coagulation time of EV-rich plasma, referred to as EV-ACT, was determined. The results revealed a significant increase in EV-ACT when EV was removed from plasma obtained from healthy volunteers, while it significantly decreased when EV was enriched. Furthermore, EV-ACT was considerably shortened in human samples from preeclampsia, hip fracture, and lung cancer, indicating elevated levels of plasma EV and promotion of blood hypercoagulation. With its simple and rapid procedure, EV-ACT shows promise as a bedside test for evaluating coagulation function in patients with high plasma EV levels.

Author Spotlight: Deciphering Coagulation Disorders in Traumatic Brain Injury Patients 

Determination of the Procoagulant Activity of Extracellular Vesicle (EV) Using EV-Activated Clotting Time (EV-ACT)

The thrombin activation time of EV-rich plasma was measured using a viscoelastic method analyzer for plasma coagulation time measurement. The machine consists of four main components: an electronic signal converter, a probe, a detection tank, and a heating element (Figure 1A,B). The probe utilizes high-frequency and low-amplitude oscillations to detect changes in plasma viscosity. Daily quality control primarily involves air quality control to assess the stability of the tes...

Watch this Scientific Journal Video about Deciphering Coagulation Disorders in Traumatic Brain Injury Patients at JoVE.com

This protocol investigates the use of extracellular vesicle (EV)-rich plasma as an indicator of the coagulative ability of EV. EV-rich plasma is obtained through a process of differential centrifugation and subsequent recalcification.

The role of extracellular vesicles (EV) in various diseases is gaining increased attention, particularly due to their potent procoagulant activity. ...