■循环促凝血细胞外囊泡(EV)在疾病中增加,比如癌症,脓毒症,和COVID-19。EV组织因子(TF)活性与胰腺癌和COVID-19患者脓毒症和静脉血栓形成的弥散性血管内凝血相关。电动汽车通常通过〜20,000g的离心分离。
■在本研究中,我们分析了两种败血症患者中富含大型和小型EV的2例EV人群的TF活性,胰腺癌,或者COVID-19。
■通过以20,000g的顺序离心从血浆中分离出EV(大型EV,LEV),然后是100,000克(小型电动汽车,SEVs).我们分析了从有或没有脂多糖(LPS)刺激的健康个体的全血样品制备的血浆中的EV,以及来自败血症患者的血浆样品中的EV。胰腺癌,或者COVID-19。测量EV的TF依赖性(EV-TF活性)和TF非依赖性因子Xa(FXa)生成。
■LPS增加了LEV而不是SEV的EV-TF活性。同样,在2例EV-TF活性高于试验背景的脓毒症患者中,我们观察到了LEV而非SEV中的EV-TF活性.胰腺癌或COVID-19患者在LEV和SEV中均有循环EV-TF活性。
■我们建议通过100,000g而不是20,000g离心从患者的血浆中分离EV,以获得更准确的循环EV-TF活性水平测量。
UNASSIGNED: Circulating procoagulant extracellular vesicles (EVs) are increased in diseases, such as cancer, sepsis, and COVID-19. EV tissue factor (TF) activity is associated with disseminated intravascular coagulation in sepsis and venous thrombosis in patients with pancreatic cancer and COVID-19. EVs are commonly isolated by centrifugation at ∼20,000 g.
UNASSIGNED: In this study, we analyzed the TF activity of 2 EV populations enriched for large and small EVs in patients with either sepsis, pancreatic cancer, or COVID-19.
UNASSIGNED: EVs were isolated from plasma by sequential centrifugation at 20,000 g (large EVs, LEVs) and then 100,000 g (small EVs, SEVs). We analyzed EVs from plasma prepared from whole blood samples from healthy individuals with or without lipopolysaccharide (LPS) stimulation as well as EVs from plasma samples from patients with either sepsis, pancreatic cancer, or COVID-19. TF-dependent (EV-TF activity) and TF-independent factor Xa (FXa) generation of the EVs was measured.
UNASSIGNED: LPS increased EV-TF activity in LEVs but not SEVs. Similarly, in 2 patients with sepsis who had EV-TF activity above the background of the assay we observed EV-TF activity in LEVs but not SEVs. Patients with pancreatic cancer or COVID-19 had circulating EV-TF activity in both LEVs and SEVs.
UNASSIGNED: We recommend that EVs are isolated from plasma from patients by centrifugation at 100,000 g rather than 20,000 g to obtain a more accurate measure of levels of circulating EV-TF activity.