thromboplastin and Uremia

Topics: Anticoagulants; Blood Coagulation; Blood Coagulation Disorders; Factor VIII; Fibrinolytic Agents; Hematuria; Hemostasis; Heparin; Humans; Kidney; Kidney Cortex Necrosis; Kidney Transplantation; Methods; Renal Dialysis; Thromboembolism; Thromboplastin; Uremia

Topics: Adult; Blood Coagulation Disorders; Blood Coagulation Factors; Blood Coagulation Tests; Blood Flow Velocity; Child; Child, Preschool; Clinical Laboratory Techniques; Dextrans; Female; Fibrinolytic Agents; Glomerulonephritis; Hemangioma, Cavernous; Heparin; Humans; Infections; Liver Cirrhosis; Male; Mycoses; Parasitic Diseases; Pregnancy; Pregnancy Complications; Purpura; Shock; Thrombocytopenia; Thromboplastin; Uremia

Some parameters of extrinsic coagulation pathway, including concentration and activity of tissue factor and concentration of tissue factor pathway inhibitor, have been estimated in uremic hemodialysis patients. The impact of erythropoietin treatment on the extrinsic coagulation pathway has also been the aim of the study. Increased concentration of tissue factor pathway inhibitor--TFPI has been found both in dialysed and non-dialysed uremic patients. This finding may be the evidence of endothelial damage as well as the protective factor against thrombotic complications. Erythropoietin treatment seemed not to induce statistically significant changes in extrinsic coagulation pathway. Some results indicate that estimation of "truncated' and "full length" forms of TFPI may be more useful comparing to complete TFPI concentration.

Topics: Adult; Aged; Anticoagulants; Blood Coagulation; Erythropoietin; Female; Humans; Lipoproteins; Male; Middle Aged; Renal Dialysis; Thromboplastin; Thrombosis; Treatment Outcome; Uremia

Plasma von Willebrand factor antigen, soluble thrombomodulin, and tissue factor were increased in 31 patients with severe chronic renal failure (creatinine clearance <20 ml/min) under conservative treatment, whereas plasminogen activator inhibitor antigen did not differ significantly from healthy controls. No correlation among plasma levels of these proteins was found. Three patterns of relationship between endothelial cell markers and hemostatic defects were identified: 1) Plasma thrombomodulin, a marker of endothelium damage, was found an independent predictor of bleeding time and platelet aggregation, and secretion defects, and was also related to the severity of renal failure; 2) von Willebrand factor antigen, an index of endothelial cell activation and secretion, was significantly correlated with intravascular markers of thrombin and plasmin generation and with platelet adenosine triphosphate content, but not with plasma creatinine levels; and 3) tissue factor and plasminogen activator inhibitor antigen levels were not statistically correlated with the diverse hemostatic defects. Activation of coagulation and fibrinolysis, secondary to endothelial cell activation, appearing early during the evolution of chronic renal failure, is pathogenically related to the platelet dysfunction, and probably to development of atherosclerosis and thrombotic events in this disease. The progression of chronic renal failure, through endothelial cell damage, would lead to aggravation of the platelet functional defect potentiating the hemorrhagic risk.

Topics: Antigens; Biomarkers; Blood Coagulation; Chronic Disease; Disease Progression; Endothelium, Vascular; Fibrinolysis; Hemostasis; Humans; Kidney Failure, Chronic; Plasminogen Activator Inhibitor 1; Thrombomodulin; Thromboplastin; Uremia; von Willebrand Factor

CKD, characterized by retained uremic solutes, is a strong and independent risk factor for thrombosis after vascular procedures . Urem ic solutes such as indoxyl sulfate (IS) and kynurenine (Kyn) mediate prothrombotic effect through tissue factor (TF). IS and Kyn biogenesis depends on multiple enzymes, with therapeutic implications unexplored. We examined the role of indoleamine 2,3-dioxygenase-1 (IDO-1), a rate-limiting enzyme of kynurenine biogenesis, in CKD-associated thrombosis after vascular injury.. IDO-1 expression in mice and human vessels was examined. IDO-1. Both global IDO-1. Leveraging genetic and pharmacologic manipulation in experimental models and data from human studies implicate IS as an inducer of IDO-1 and a perpetuator of the thrombotic milieu and supports IDO-1 as an antithrombotic target in CKD.

Topics: Animals; Aorta; Carotid Artery Injuries; Carotid Artery Thrombosis; Culture Media; Enzyme Induction; Feedback, Physiological; Female; HEK293 Cells; Humans; Indican; Indoleamine-Pyrrole 2,3,-Dioxygenase; Kynurenine; Mice; Mice, Inbred C57BL; Mice, Knockout; Molecular Targeted Therapy; Myocytes, Smooth Muscle; Postoperative Complications; Renal Insufficiency, Chronic; Thromboplastin; Thrombosis; Tryptophan; Uremia; Vascular Surgical Procedures

Patients with chronic kidney disease (CKD) commonly exhibit hypercoagulability. Increased levels of uremic toxins cause thrombogenicity by increasing tissue factor (TF) expression and activating the extrinsic coagulation cascade. TF is induced in monocytes and macrophages under pathological conditions, such as inflammatory diseases. However, the role of monocyte myeloid cell TF in CKD progression remains unclear. We aimed to clarify this issue, and the present study found that patients with CKD had elevated levels of D-dimer, a marker of fibrin degradation, which was associated with decreased estimated glomerular filtration rate and increased serum levels of uremic toxins, such as indoxyl sulfate. In vitro studies showed that several uremic toxins increased cellular TF levels in monocytic THP-1 cells. Mice with TF specifically deleted in myeloid cells were fed an adenine diet to cause uremic kidney injury. Myeloid TF deletion reduced tubular injury and pro-inflammatory gene expression in the kidneys of adenine-induced CKD but did not improve renal function as measured by plasma creatinine or blood urea nitrogen. Collectively, our findings suggest a novel concept of pathogenesis of coagulation-mediated kidney injury, in which elevated TF levels in monocytes under uremic conditions is partly involved in the development of CKD.

Topics: Adenine; Animals; Fibrin Fibrinogen Degradation Products; Glomerular Filtration Rate; Humans; Kidney Tubules; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Myeloid Cells; Renal Insufficiency, Chronic; Thromboplastin; Toxins, Biological; Uremia

Individuals with CKD are particularly predisposed to thrombosis after vascular injury. Using mouse models, we recently described indoxyl sulfate, a tryptophan metabolite retained in CKD and an activator of tissue factor (TF) through aryl hydrocarbon receptor (AHR) signaling, as an inducer of thrombosis across the CKD spectrum. However, the translation of findings from animal models to humans is often challenging. Here, we investigated the uremic solute-AHR-TF thrombosis axis in two human cohorts, using a targeted metabolomics approach to probe a set of tryptophan products and high-throughput assays to measure AHR and TF activity. Analysis of baseline serum samples was performed from 473 participants with advanced CKD from the Dialysis Access Consortium Clopidogrel Prevention of Early AV Fistula Thrombosis trial. Participants with subsequent arteriovenous thrombosis had significantly higher levels of indoxyl sulfate and kynurenine, another uremic solute, and greater activity of AHR and TF, than those without thrombosis. Pattern recognition analysis using the components of the thrombosis axis facilitated clustering of the thrombotic and nonthrombotic groups. We further validated these findings using 377 baseline samples from participants in the Thrombolysis in Myocardial Infarction II trial, many of whom had CKD stage 2-3. Mechanistic probing revealed that kynurenine enhances thrombosis after vascular injury in an animal model and regulates thrombosis in an AHR-dependent manner. This human validation of the solute-AHR-TF axis supports further studies probing its utility in risk stratification of patients with CKD and exploring its role in other diseases with heightened risk of thrombosis.

Topics: Adult; Aged; Clinical Trials as Topic; Female; Humans; Indican; Kynurenine; Male; Metabolomics; Middle Aged; Pattern Recognition, Automated; Receptors, Aryl Hydrocarbon; Renal Insufficiency, Chronic; Signal Transduction; Thromboplastin; Thrombosis; Uremia; Vascular System Injuries

Patients with CKD suffer high rates of thrombosis, particularly after endovascular interventions, yet few options are available to improve management and reduce thrombotic risk. We recently demonstrated that indoxyl sulfate (IS) is a potent CKD-specific prothrombotic metabolite that induces tissue factor (TF) in vascular smooth muscle cells (vSMCs), although the precise mechanism and treatment implications remain unclear. Because IS is an agonist of the aryl hydrocarbon receptor (AHR), we first examined the relationship between IS levels and AHR-inducing activity in sera of patients with ESRD. IS levels correlated significantly with both vSMC AHR activity and TF activity. Mechanistically, we demonstrated that IS activates the AHR pathway in primary human aortic vSMCs, and further, that AHR interacts directly with and stabilizes functional TF. Antagonists directly targeting AHR enhanced TF ubiquitination and degradation and suppressed thrombosis in a postinterventional model of CKD and endovascular injury. Furthermore, AHR antagonists inhibited TF in a manner dependent on circulating IS levels. In conclusion, we demonstrated that IS regulates TF stability through AHR signaling and uncovered AHR as an antithrombotic target and AHR antagonists as a novel class of antithrombotics. Together, IS and AHR have potential as uremia-specific biomarkers and targets that may be leveraged as a promising theranostic platform to better manage the elevated thrombosis rates in patients with CKD.

Topics: Adult; Female; Humans; Indican; Male; Middle Aged; Protein Stability; Receptors, Aryl Hydrocarbon; Thromboplastin; Thrombosis; Uremia

Increased accumulation of indolic uremic solutes in the blood of uremic patients contributes to the risk of thrombotic events. Red blood cells (RBCs), the most abundant blood cells in circulation, may be a privileged target of these solutes. However, the effect of uremic solutes indoxyl sulfate (IS) and indole-3-acetic acid (IAA) on procoagulant activity (PCA) of erythrocyte is unclear. Here, RBCs from healthy adults were treated with IS and IAA (mean and maximal concentrations reported in uremic patients). Phosphatidylserine (PS) exposure of RBCs and their microparticles (MPs) release were labeled with Alexa Fluor 488-lactadherin and detected by flow cytometer. Cytosolic Ca(2+) ([Ca(2+)]) with Fluo 3/AM was analyzed by flow cytometer. PCA was assessed by clotting time and purified coagulation complex assays. We found that PS exposure, MPs generation, and consequent PCA of RBCs at mean concentrations of IS and IAA enhanced and peaked in maximal uremic concentrations. Moreover, 128 nM lactadherin, a PS inhibitor, inhibited over 90% PCA of RBCs and RMPs. Eryptosis or damage, by indolic uremic solutes was due to, at least partially, the increase of cytosolic [Ca(2+)]. Our results suggest that RBC eryptosis in uremic solutes IS and IAA plays an important role in thrombus formation through releasing RMPs and exposing PS. Lactadherin acts as an efficient anticoagulant in this process.

Topics: Anticoagulants; Blood Coagulation; Calcium; Cell-Derived Microparticles; Cytosol; Erythrocytes; Factor Xa; Female; Flow Cytometry; Humans; Indican; Indoleacetic Acids; Indoles; Male; Phosphatidylserines; Thromboplastin; Thrombosis; Uremia; Young Adult

The mechanisms contributing to an increased risk of thrombosis in uremia are complex and require clarification. There is scant morphological evidence of membrane-dependent binding of factor Xa (FXa) and factor Va (FVa) on endothelial cells (EC) in vitro. Our objectives were to confirm that exposed phosphatidylserine (PS) on microparticle (MP), EC, and peripheral blood cell (PBC) has a prothrombotic role in uremic patients and to provide visible and morphological evidence of PS-dependent prothrombinase assembly in vitro. We found that uremic patients had more circulating MP (derived from PBC and EC) than controls. Additionally, patients had more exposed PS on their MPs and PBCs, especially in the hemodialysis group. In vitro, EC exposed more PS in uremic toxins or serum. Moreover, reconstitution experiments showed that at the early stages, PS exposure was partially reversible. Using confocal microscopy, we observed that PS-rich membranes of EC and MP provided binding sites for FVa and FXa. Further, exposure of PS in uremia resulted in increased generation of FXa, thrombin, and fibrin and significantly shortened coagulation time. Lactadherin, a protein that blocks PS, reduced 80% of procoagulant activity on PBC, EC, and MP. Our results suggest that PBC and EC in uremic milieu are easily injured or activated, which exposes PS and causes a release of MP, providing abundant procoagulant membrane surfaces and thus facilitating thrombus formation. Blocking PS binding sites could become a new therapeutic target for preventing thrombosis.

Topics: Adult; Aged; Animals; Blood Coagulation; Cattle; Cell-Derived Microparticles; Coagulants; Endothelial Cells; Factor Xa; Female; Fibrin; Flow Cytometry; Human Umbilical Vein Endothelial Cells; Humans; Male; Membrane Glycoproteins; Microscopy, Confocal; Middle Aged; Milk Proteins; Phosphatidylserines; Thrombin; Thromboplastin; Thrombosis; Uremia

Stent thrombosis (ST), a postinterventional complication with a mortality rate of 50%, has an incidence that rises precipitously in patients at risk. Chronic renal failure and end-stage renal disease have emerged as particularly strong ST risk factors, yet the mechanism remains elusive. Tissue factor (TF) is a crucial mediator of injury-related thrombosis and has been implicated for ST. We posit that uremia modulates TF in the local vessel wall to induce postinterventional thrombosis in patients with end-stage renal disease.. As a model of the de-endothelialized, postinterventional state, we exposed primary human vascular smooth muscle cells (vSMCs) pretreated with uremic serum (obtained from ESRD patients on hemodialysis) to coronary-like blood flow. vSMC TF expression, activity, stability, and posttranslational modification were examined after vSMCs were treated with uremic serum or solutes. We found significantly greater clot formation after uremic serum exposure, which was substantially reduced with the prior treatment with anti-TF neutralizing antibody. Uremic sera induced 2- to 3-fold higher TF expression and activity in vSMCs independent of diabetes mellitus. Relevant concentrations of isolated uremic solutes such as indole-3-acetic acid (3.5 μg/mL), indoxyl sulfate (25 μg/mL), and uric acid (80 μg/mL) recapitulated these effects in cell culture and the flow loop model. We show further that TF undergoes ubiquitination at baseline and that uremic serum, indole-3-acetic acid, and indoxyl sulfate significantly prolong TF half-life by inhibiting its ubiquitination.. The uremic milieu is profoundly thrombogenic and upregulates vSMC TF levels by increasing TF stability and decreasing its ubiquitination. Together, these data demonstrate for the first time that the posttranslational regulation of TF in uremia may have a causative role in the increased ST risk observed in uremic patients. These data suggest that interventions that reduce vSMC TF may help to prevent ST and that uremic solutes should be considered as novel risk factors for ST in patients with chronic renal failure.

Topics: Adult; Aged; Cell Line; Coronary Vessels; Endothelium, Vascular; Female; Humans; In Vitro Techniques; Indican; Indoleacetic Acids; Kidney Failure, Chronic; Male; Middle Aged; Myocytes, Smooth Muscle; Renal Dialysis; Risk Factors; Serum; Stents; Thromboplastin; Thrombosis; Ubiquitination; Uremia

Topics: Female; Humans; Kidney Failure, Chronic; Male; Myocytes, Smooth Muscle; Serum; Stents; Thromboplastin; Thrombosis; Uremia

Patients with end-stage renal disease (ESRD) exhibit features of a hypercoagulable state, which may contribute to atherosclerosis. Kynurenines are the metabolites of tryptophan degradation in mammals. We examined the relationship between coagulation activation and kynurenines in 92 patients with ESRD on maintenance haemodialysis (HD) or continuous ambulatory peritoneal dialysis (CAPD) and 20 healthy controls. We measured the plasma levels of: tissue factor (TF), its pathway inhibitor (TFPI), the marker of coagulation activation - prothrombin fragments 1+2 (F(1+2)), kynurenine (KYN) and its metabolites: kynurenic (KYNA), anthranilic (AA) and quinolinic (QA) acids. The ratio of KYNA to KYN (kyna/kyn), AA to KYN (aa/kyn) and QA to KYN (qa/kyn), reflecting intensified activity of enzymes which converted KYN to its metabolites, were also determined. Measured coagulation parameters and kynurenines were significantly elevated in ESRD patients compared to controls. TF, TFPI and F(1+2) were significantly associated with AA, aa/kyn, QA and qa/kyn ratio. Multiple regression analysis showed that fibrinogen (p<0.01) and above mentioned KYN metabolites (all p<0.05) were the independent variables significantly associated with increased F(1+2) levels, reflecting hypercoagulability in ESRD patients. In conclusion, this study represents the first to investigate both the coagulation system and KYN pathway in ESRD patients. The coagulation was enhanced in dialysed uraemic patients compared with the healthy controls demonstrated by increased TF, TFPI and F(1+2) levels. These changes were correlated with activation of the KYN pathway. Finally, fibrinogen and KYN metabolites are independently and significantly associated with the hypercoagulable state in uraemic patients on CAPD and HD treatment.

Topics: Adult; Aged; Blood Coagulation; Female; Humans; Kidney Failure, Chronic; Kynurenine; Lipoproteins; Male; Middle Aged; Peptide Fragments; Peritoneal Dialysis, Continuous Ambulatory; Protein Precursors; Prothrombin; Renal Dialysis; Thrombophilia; Thromboplastin; Uremia

We have investigated the ability of serum from uremic patients to modify the thrombogenic properties of the endothelium. The effects of uremic medium on the morphology of endothelial cells (ECs), and their resistance to flow was analyzed. The influence of uremic media on the reactivity of the extracellular matrix (ECM) generated by ECs towards normal platelets was evaluated in a parallel-plate perfusion chamber. Exposure of ECs to uremic medium resulted in abnormal cell morphology and signs of an accelerated growth. Detachment of ECs exposed to circulating blood was increased when cells had been grown with media supplemented with uremic serum (21% vs. 14% non exposed). Platelet deposition was significantly elevated on ECMs generated in the presence of uremic media (uremicECMs) (p<0.01 vs. control studies). Effects of uremic serum were not observed at short incubation periods (5 h) but were evident after 24 or 72 h of incubation. Northern blot analysis revealed increased expression of tissue factor (TF) mRNA in ECs exposed to uremic conditions. Immunocytochemical methods detected an augmented expression of TF antigen on uremic ECMs. Incubation of ECMs with an antibody to human tissue factor prevented the increase in platelet deposition observed in uremic ECMs, suggesting that the presence of TF in ECM could be responsible for the enhanced platelet deposition. Results from our study indicate that uremic medium impairs the antithrombotic functions of cultured endothelial cells.

Topics: Biological Factors; Blood Platelets; Cells, Cultured; Culture Media; Endothelium, Vascular; Extracellular Matrix; Gene Expression Regulation; Hemostasis; Humans; Immunohistochemistry; Platelet Adhesiveness; RNA, Messenger; Thromboplastin; Umbilical Veins; Uremia

So far it is not clear how erythropoietin affects the anticoagulant properties of vascular endothelium in uremia. Since serotonin is also thought to play a role in the pathogenesis of thrombosis, the aim of the study was to evaluate major components of extrinsic coagulation pathway, markers of endothelial cell injury, lipoprotein (a) and peripheral serotonergic mechanisms during rHuEPO therapy in hemodialyzed patients. The study was performed on chronically hemodialyzed patients divided into two groups: with rHuEPO treatment and without rHuEPO therapy in relation to the control group. In uremic patients, thrombomodulin and von Willebrand factor, activity of factor VII, tissue factor pathway inhibitor (TFPI) activity, TFPI and tissue factor (TF) concentrations, lipoprotein (a) level were significantly higher when compared to healthy volunteers. Treatment with rHuEPO resulted in a further significant rise in markers of endothelial cell injury: thrombomodulin and von Willebrand factor and TFPI concentration. Extrinsic coagulation factors: activities of factor VII and X, TFPI activity and TF activity and concentration, lipoprotein (a) and vitronectin remained unchanged during rHuEPO therapy. Platelet serotonin content and whole blood serotonin were significantly lower in uremic patients relative to healthy volunteers and during rHuEPO treatment they increased significantly. Whole blood serotonin reached normal values. Plasma serotonin, significantly elevated in uremia, did not change during rHuEPO therapy. Serotonin uptake by uremic platelets was significantly impaired and remained unaltered during rHuEPO administration. Serotonin release by uremic platelets was also significantly depressed but a significant improvement was observed in rHuEPO-treated patients. Our data suggest that endothelial injury, TF pathway components and peripheral serotonergic system disturbances may predispose to thromboembolic complications and play a role in the pathogenesis of atherosclerosis in uremic patients, particularly treated with rHuEPO. Increase in TFPI may compensate the increase in TF in these patients.

Topics: Adult; Aged; Arteriosclerosis; Blood Coagulation; Blood Platelets; Case-Control Studies; Endothelium, Vascular; Erythropoietin; Female; Humans; Lipoproteins; Male; Middle Aged; Recombinant Proteins; Renal Dialysis; Serotonin; Thromboplastin; Thrombosis; Uremia

We investigated plasma activated factor VII (FVIIa) levels in uremic patients (nondialysis group: n = 38; dialysis group: n = 36) and healthy controls (n = 32). We also measured the plasma levels of thrombomodulin (an indicator of endothelial cell injury) and tissue factor. Plasma FVIIa showed a marked increase in the nondialysis group (mean [95% confidence interval]: 4.6 [4.1-5.1] ng/ml, p < 0.0001) with the progressive impairment of renal function, as indicated by the serum creatinine level, when compared with the 32 controls (2.8 [2.5-3.1] ng/ml), and was further increased in the dialysis group (6.1 [5.5-6.8] ng/ml, p < 0.001 vs. nondialysis group). Plasma levels of thrombomodulin and tissue factor were also higher in the nondialysis group than the control group, and were further increased in the dialysis group. Plasma tissue factor levels did not show any correlation with FVIIa or thrombomodulin in both the nondialysis and dialysis groups. Thus, circulating tissue factor appears to be released by a different mechanism from thrombomodulin and may not contribute to the direct activation of factor VII in uremic patients. On the other hand, the plasma level of thrombomodulin was positively correlated with that of FVIIa in the nondialysis group, and this correlation was independent of renal function. Thus, enhanced conversion of factor VII zymogen to FVIIa, probably related to endothelial cell injury, may be a risk factor for cardiovascular events in uremic patients.

Topics: Aged; Cardiovascular Diseases; Creatinine; Diabetic Nephropathies; Endothelium, Vascular; Factor VII; Factor VIIa; Female; Glomerulonephritis; Humans; Male; Middle Aged; Renal Dialysis; Risk Factors; Thrombomodulin; Thromboplastin; Uremia

Topics: Blood Coagulation Disorders; Blood Coagulation Tests; Capillary Resistance; Humans; Thromboplastin; Uremia

Topics: Blood Coagulation Disorders; Blood Coagulation Tests; Centrifugation; Hemophilia A; Humans; Methods; Thromboplastin; Uremia

Topics: Blood Coagulation Disorders; Hemolysis; Humans; Mononuclear Phagocyte System; Thromboplastin; Uremia

Topics: Blood Coagulation; Blood Coagulation Tests; Blood Platelets; Hemorrhagic Disorders; Humans; Kidney Failure, Chronic; Kidney Transplantation; Thromboplastin; Transplantation, Homologous; Uremia

Topics: Anemia, Macrocytic; Blood Platelet Disorders; Blood Platelets; Chromatography, Paper; Female; Humans; In Vitro Techniques; Ovarian Diseases; Phospholipids; Polycythemia Vera; Primary Myelofibrosis; Prothrombin; Thrombin; Thromboplastin; Uremia

Topics: Blood Coagulation Factors; Hemostasis; Humans; Physiology; Research; Thromboplastin; Uremia