thromboplastin and Aortic-Aneurysm--Abdominal

Innate immunity and chronic inflammation are involved in atherosclerosis and atherothrombosis, leading to target organ damage in essential hypertension (EH). However, the role of neutrophils in EH is still elusive. We investigated the association between angiotensin II (Ang II) and neutrophil extracellular traps (NETs) in pathogenesis of EH. Plasma samples, kidney biopsies, and surgical specimens of abdominal aortic aneurysms (AAAs) from patients with EH were used. Cell-based assays, NETs/human aortic endothelial cell cocultures, and in situ studies were performed. Increased plasma levels of NETs and tissue factor (TF) activity were detected in untreated, newly diagnosed patients with EH. Stimulation of control neutrophils with plasma from patients with untreated EH generated TF-enriched NETs promoting endothelial collagen production. Ang II induced NETosis in vitro via an ROS/peptidylarginine deiminase type 4 and autophagy-dependent pathway. Circulating NETs and thrombin generation levels were reduced substantially in patients with EH starting treatment with Ang II receptor blockers, whereas their plasma was unable to trigger procoagulant NETs. Moreover, TF-bearing NETotic neutrophils/remnants accumulated in sites of interstitial renal fibrosis and in the subendothelial layer of AAAs. These data reveal the important pathogenic role of an Ang II/ROS/NET/TF axis in EH, linking thromboinflammation with endothelial dysfunction and fibrosis.

Topics: Angiotensin II; Angiotensin Receptor Antagonists; Aortic Aneurysm, Abdominal; Autophagy; Case-Control Studies; Cells, Cultured; Coculture Techniques; Collagen; Endothelium; Essential Hypertension; Extracellular Traps; Humans; Kidney; Neutrophils; Reactive Oxygen Species; Thrombin; Thromboinflammation; Thromboplastin; Vasoconstrictor Agents

The hemostatic system cooperates with proteolytic degradation in processes allowing abdominal aortic aneurysm (AAA) formation. In previous studies, it has been suggested that aneurysm rupture depends on intraluminal thrombus (ILT) thickness, which varies across each individual aneurysm. We hypothesized that hemostatic components differentially accumulate in AAA tissue in relation to ILT thickness. Thick (A1) and thin (B1) segments of ILTs and aneurysm wall sections A (adjacent to A1) and B (adjacent to B1) from one aneurysm sac were taken from 35 patients undergoing elective repair.. Factor levels were measured using enzyme-linked immunosorbent assay of protein extract.. Tissue factor (TF) activities were significantly higher in thinner segments of AAA (B1 vs A1, P = .003; B vs A, P < .001; B vs A1, P < .001; B vs B1, P = .001). Significantly higher tissue plasminogen activator was found in thick thrombus-covered wall segments (A) than in B, A1, and B1 (P = .015, P < .001, and P < .001, respectively). Plasminogen concentrations were highest in ILT. Concentrations of α. These results suggest that higher TF activities are present in thinner AAA regions. These parameters and local fibrinolysis may be part of the processes leading to destruction of the aneurysm wall.

Topics: Aged; alpha-2-Antiplasmin; Aorta, Abdominal; Aortic Aneurysm, Abdominal; Aortography; Computed Tomography Angiography; Dilatation, Pathologic; Female; Fibrinolysis; Humans; Male; Middle Aged; Plasminogen; Thromboplastin; Thrombosis; Tissue Plasminogen Activator; Vascular Remodeling

Topics: Aortic Aneurysm, Abdominal; Humans; Thromboplastin; Thrombosis

Tissue factor (TF), tissue factor pathway inhibitor (TFPI) and vascular endothelial growth factor A (VEGF-A) present in vascular structures take part in blood coagulation and in organ revascularisation. The concentration of thrombin-antithrombin complexes (TAT) in blood of patients with abdominal aortic aneurysms (AAA) reflects thrombin-generation.. To determine the concentration of TF, TFPI, VEGF-A and TAT complexes in blood of patients with AAA and to consider if these factors after clot formation can play a role in the pathogenesis of abdominal aortic aneurysms.. Forty eight patients (43 men and 5 women) in the age of 59-80 (mean 72) years with AAA were examined. The blood was drawn in the morning to 3.2% natrium citrate in proportion 9:1. The concentration of TF, TFPI, VEGF-A and TAT complexes were measured in plasma with commercial kits using enzyme immunoassay.. In plasma of patients with AAA the mean concentration of TF was elevated almost twice and TAT complexes were three times higher compared with controls. But the mean levels of TFPI and VEGF-A were similar as in control group.. Increased concentrations of TF and TAT complexes indicate on high thrombin-generation, hypercoagulability and formation in abdominal aortic aneurysm of intraluminal thrombus, which can induce proteolytic processes in aortic wall.

Topics: Aged; Aged, 80 and over; Antithrombin III; Aortic Aneurysm, Abdominal; Blood Coagulation Factors; Female; Humans; Male; Middle Aged; Peptide Hydrolases; Thromboplastin

Ruptured abdominal aortic aneurysm (AAA) is associated with the development of a procoagulant and hypofibrinolytic state. Tissue factor (TF) and its naturally occurring inhibitor, tissue factor pathway inhibitor (TFPI), play a central role in the initiation and progression of such a hypercoagulable state, but their role in patients undergoing open AAA repair has not previously been examined.. A prospective study was conducted of 17 patients undergoing elective AAA repair and 10 patients undergoing emergency AAA repair. Blood was taken before induction, and 5 minutes, 24 hours, and 48 hours after aortic cross-clamp release and assayed for plasma TF, TFPI, tissue plasminogen activator (t-PA), plasminogen activator inhibitor (PAI), and thrombin-activatable fibrinolysis inhibitor (TAFI) activities.. TF activity was significantly higher at all time points in patients with ruptured AAA compared with nonruptured AAA. The median (interquartile range, IRQ) TF activity (AU/mL) was 9.9 vs 3.2 (IRQ, 5.9 to 12.6 vs 2.0 to 7.6; P = .005) at preinduction; 10.7 vs 1.5 (IRQ, 9.2 to 18.3 vs 0.1 to 6.6; P = .003) at 5 minutes after clamp release; 9.5 vs 3.3 (IRQ, 7.0 to 13.5 vs 1.0 to 7.9; P = .013) at 24 hours, and 9.6 vs 3.9 (IRQ, 7.6 to 12.6 vs 2.4 to 8.7; P = .006) at 48 hours. TFPI levels were not significantly different between ruptured AAA and nonruptured AAA before or during operation but became significantly elevated at 24 and 48 hours in patients who had undergone repair of ruptured AAA. Ruptured AAA repair was associated with a hypofibrinolytic state compared with nonruptured AAA.. The present study has demonstrated for the first time, to our knowledge, that ruptured AAA is associated with significantly higher perioperative levels of circulating TF compared with nonruptured AAA. Furthermore, in the immediate perioperative period, the high levels of TF are not associated with a corresponding rise in TFPI levels, indicating an unopposed prothrombotic state. Direct inhibition of TF by administration of anti-TF antibodies or recombinant TFPI remains to be evaluated in subjects presenting with hemorrhage due to ruptured AAA, but if given early enough, it may attenuate the early deleterious effects of unopposed TF expression and ultimately contribute to improved outcomes.

Topics: Aged; Aged, 80 and over; Aortic Aneurysm, Abdominal; Aortic Rupture; Carboxypeptidase B2; Factor Xa Inhibitors; Female; Humans; Lipoproteins; Male; Middle Aged; Plasminogen Activator Inhibitor 1; Thromboplastin; Tissue Plasminogen Activator