Plasmin-antiplasmin Complex Research Articles

Perioperative cardiovascular complications rate and activity of coagulation and fibrinolysis among patients undergoing vascular surgery for peripheral artery disease and abdominal aortic aneurysm.

To compare preoperative coagulation and fibrinolysis activity and incidence of perioperative complications between patients undergoing vascular procedures for peripheral artery disease and abdominal aortic aneurysm. This is a substudy of a prospective observational cohort study (VISION; NCT00512109) in which we recruited patients aged ≥45 years, undergoing surgery for peripheral artery disease and abdominal aortic aneurysm. Blood samples were obtained 24 h preoperatively to measure platelet count, concentrations of coagulation coagulation (fibrinogen, factor VIII, von Willebrand factor:Ristocetin cofactor, antithrombin III), fibrinolysis (dimer D, plasmin-antiplasmin complexes, tissue plasminogen activator) markers and level of soluble CD40 ligand. Incidence of myocardial infarction, stroke, and death (composite endpoint) was assessed in 30-day follow-up. The study group included 131 patients at the mean age of 68.3 years among whom reason for surgery was peripheral artery disease in 77 patients (58.8%) and abdominal aortic aneurysm in 54 patients (41.2%). Peripheral artery disease group was characterized by higher platelet count (250.5 versus 209.5 (×103/µl), p = 0.001), concentrations of fibrinogen (5.4 versus 4.1 (g/l), p < 0.001), factor VIII (176.9 versus 141.9 (%), p < 0.001), von Willebrand factor:Ristocetin cofactor (188.9 versus 152.3 (%), p = 0.009), and soluble CD40 ligand (9016.0 versus 7936.6 (pg/ml), p = 0.005). The dimer D level was higher (808.0 versus 2590.5 (ng/ml), p < 0.001) in the abdominal aortic aneurysm group. Incidence of major cardiovascular events (death, myocardial infarction, stroke) within 30 days from surgery did not differ between the groups (39.0% versus 29.6%, p = 0.27). The study suggests higher activation of coagulation and relatively lower fibrinolytic activity in peripheral artery disease group compared to patients undergoing surgery for abdominal aortic aneurysm without a significant difference in cardiovascular outcomes.

A prospective observational study of acute traumatic coagulopathy in traumatic bleeding from the battlefield.

Acute trauma coagulopathy (ATC) after military trauma has not been comprehensively studied. ATC is defined as a prolonged prothrombin time ratio (PTr) or reduced clot amplitude (A5) in viscoelastic testing. Compared to civilian trauma, military trauma has more injuries from explosions and gunshot wounds (GSWs), potentially leading to a different pathophysiology for traumatic coagulopathy. This study aimed to characterize military ATC on admission to a military hospital in Afghanistan and to explore any differences due to the mechanism of injury. Severely injured military casualties were enrolled in the study. Blood samples were taken on admission and after routine testing, waste plasma was prepared, frozen, and transported to the United Kingdom for in-depth hemostatic analysis. Seventy-seven percent of casualties had ATC defined by a PTr greater than 1.2 and 19% when defined by rotational thromboelastometry (ROTEM) A5 less than 36 mm. Coagulation factor depletion correlated with degree of shock, particularly factor V (p < 0.01), factor X (p < 0.01), and fibrinogen levels (p < 0.01). Thrombin generation was well preserved. Fibrinolytic biomarkers were raised correlating with the degree of shock (p < 0.01), and 8% of casualties had hyperfibrinolysis on ROTEM analysis. Plasmin-antiplasmin complexes (p < 0.01) and d-dimer levels (p = 0.01) were higher and clot firmness lower (p = 0.02) in those injured by explosion compared to GSW's. ATC was present and correlated with shock, similar to civilian trauma. Thrombin generation remained adequate. Fibrinogen and factor V levels were disproportionately low but still sufficient to allow clot formation. Fibrinolysis is a key feature, probably due to a tissue plasminogen activator surge at the time of injury. Blast injuries are associated with a greater activation of fibrinolysis than GSWs.

Characteristics of emergency patients with markedly elevated D-dimer levels

Background: Markedly elevated D-dimer levels can occur in emergency patients with various clinical situations, and is likely to indicate the presence of coagulopathy, rapid differential diagnosis was crucial for them. Methods: D-dimer was detected in consecutive 813 patients entering the emergency department of our hospital, for the patients with D-dimer levels above 5.0 µg/mL, the final diagnoses and 28-day mortality were confirmed, and the levels of thrombomodulin (TM), thrombin-antithrombin complex (TAT) and plasmin-antiplasmin complex (PAP) on admission were detected. Results: There were 148 emergency patients with D-dimer levels higher than 5.0 µg/mL mainly due to sepsis, malignancy, trauma, venous thromboembolism (VTE), cerebrovascular accident, and so on. Both of the TM and TAT levels among these diagnoses were significantly different (p < 0.001). The elevated TM (>13.3 TU/mL) had a predictive value of 96.0% for excluding VTE, and the normal TM had a predictive value of 90.4% for excluding sepsis. The overall 28-day mortality of these patients with D-dimer >5.0 ug/mL was 14.2%, the TAT level on admission was independently associated with 28-day mortality (odds ratio 1.014, 95% CI 1.001–1.027, P = 0.030). Conclusions: The medical emergencies associated with markedly elevated D-dimer levels were revealed, specific markers of endothelial dysfunction and thrombin generation measured by automatic analyzer have the potential to distinguish diagnoses and predict outcomes in these patients.

P1902Comparison of efficacy of different anticoagulation strategies used during pulmonary vein isolation in left atrial blood samples

Abstract Introduction Ablation of atrial fibrillation is based on the isolation of the pulmonary veins (PVI) from the left atrium. Cerebral thromboembolism is a rare but serious complication of PVI, which highlights the importance of peri-procedural anticoagulation. Aim Studying the coagulation and endothelium activation during PVI in case of using different anticoagulation protocols. Method 52 patients undergoing PVI with cryoballoon technique were involved and were grouped according to three different pre-procedural anticoagulation strategies: in the first group patients received no anticoagulation before the procedure (non anticoag., 24 patients)-, in the second group patients received uninterrupted vitamin K antagonist therapy, and their INR value was in therapeutic range on the day of the procedure (VKA group, 11 patients) and in the third group patients were on uninterrupted dabigatran therapy (dabigatran group, 17 patients). Two blood samples were taken during PVI from the left atrium, the first one before ablation or iv. heparin administration, the second one directly after the last application at the end of the procedure. The samples were used to measure D-dimer, plasmin antiplasmin (PAP) complex, a2 plasmin inhibitor (a2PI), plasminogen, FVIII activity, von Willebrand factor (VWF) antigen levels. Results D-dimer levels increased in all three groups after ablation, but in the samples of patients on dabigatran therapy we detected significantly lower D-dimer levels in the pre- and post-procedural samples compared to patients on other therapeutic strategies (median values before or after PVI: non anticoag.: 0.48 and 1.09 mgFEU/L; VKA: 0.33 and 0.72 mgFEU/L, dabigatran: 0.12 and 0.30 mgFEU/L, p&lt;0.001 non anticoag. vs. dabigatran, p&lt;0.01 VKA vs. dabigatran). PAP complex values were increasing parallel with D-dimer levels and only in the dabigatran group did not increase significantly. VWF antigen and FVIII activity increased significantly in all three groups after ablation, but there was no significant difference between the groups. Conclusions the safest anticoagulation strategy for patients undergoing PVI was uninterrupted dabigatran therapy. The extend of endothelial damage was not affected by anticoagulation.

Defibrotide enhances fibrinolysis in human endotoxemia \u2013 a randomized, double blind, crossover trial in healthy volunteers

Defibrotide is approved for the treatment of sinusoidal obstruction syndrome after allogeneic stem cell transplantation. The exact mode of action of defibrotide is unclear and human in vivo data are scarce. In this randomized, double blind, crossover trial we included 20 healthy volunteers. Four were randomized to receive placebo, while 16 received a 2 ng/kg bodyweight bolus of lipopolysaccharide (LPS). Infusion of 6.25 mg/kg defibrotide or placebo was started one hour before the injection of the LPS bolus. Plasma levels of prothrombin fragments F1 + 2, thrombin-antithrombin complexes, von Willebrand factor, E-selectin, tissue-type plasminogen activator (t-PA), plasminogen activator inhibitor-1 (PAI-1), plasmin-antiplasmin complexes (PAP), tumor necrosis factor-α, interleukin 6, and C-reactive protein were measured. Thromboelastometry was performed. Infusion of defibrotide did not reduce the LPS-induced activation of coagulation, the endothelium or the release of pro-inflammatory cytokines. However, defibrotide increased t-PA antigen levels by 31% (Quartiles: 2–49%, p = 0.026) and PAP concentrations by 13% (−4–41%, p = 0.039), while PAI-1 levels remained unaffected. Moreover, defibrotide reduced C-reactive protein levels by 13% (0–17%, p = 0.002). A transient increase in the clotting time in thromboelastometry and a decrease in F1 + 2 prothrombin fragments suggests modest anticoagulant properties. In conclusion, defibrotide infusion enhanced fibrinolysis and reduced C-reactive protein levels during experimental endotoxemia.

Impact of Arterial Procedures on Coagulation and Fibrinolysis - A Pilot Study.

ObjectiveThe main goal of our study was to assess the impact of vascular procedures on the activity of hemostatic and fibrinolytic pathways.MethodsWe enrolled 38 patients with ≥ 45 years old undergoing surgery for abdominal aortic aneurysm or peripheral artery disease under general or regional anesthesia and who were hospitalized at least one night after the procedure. Patients undergoing carotid artery surgery and those who had acute bypass graft thrombosis, cancer, renal failure defined as estimated glomerular filtration rate < 30 ml/min/1.73m2, venous thromboembolism three months prior to surgery, or acute infection were excluded from the study. We measured levels of markers of hemostasis (factor VIII, von Willebrand factor:ristocetin cofactor [vWF:CoR], antithrombin), fibrinolysis (D-dimer, tissue plasminogen activator [tPA], plasmin-antiplasmin complexes), and soluble cluster of differentiation 40 ligand (sCD40L) before and 6-12h after vascular procedure.ResultsSignificant differences between preoperative and postoperative levels of factor VIII (158.0 vs. 103.3, P<0.001), antithrombin (92.1 vs. 74.8, P<0.001), D-dimer (938.0 vs. 2406.0, P=0.005), tPA (10.1 vs. 12.8, P=0.002), and sCD40L (9092.9 vs. 1249.6, P<0.001) were observed. There were no significant differences between pre- and postoperative levels of vWF:CoR (140.6 vs. 162.8, P=0.17) and plasmin-antiplasmin complexes (749.6 vs. 863.7, P=0.21).ConclusionVascular surgery leads to significant alterations in hemostatic and fibrinolytic systems. However, the direction of these changes in both pathways remains unclear and seems to be different depending on the type of surgery. A study utilizing dynamic methods of coagulation and fibrinolysis assessment performed on a larger population is warranted.

Hyperactivation of Plasmin Following Severe Burn Is Associated with Systemic Inflammation and Coagulopathy

▪ INTRODUCTIONSevere injury provokes coagulopathy and systemic inflammatory response syndrome (SIRS) that, in concurrence, greatly increase the risk of life-threatening complications including bleeding, thrombosis, and multi-organ dysfunction syndrome (MODS), making it a leading cause of death and disability worldwide. For centuries, surgeons have observed hyperactivation of the enzyme plasmin (hyperfibrinolysis) following severe injury and its detrimental effects on bleeding in these patients. Recently, it has been demonstrated that the function of plasmin extends well beyond fibrinolysis to the modulation of inflammation and coagulation, suggesting it may alter the systemic inflammatory and coagulation response to severe injury. We hypothesize that early hyperactivation of plasmin augments systemic inflammation and coagulopathy following severe injury. METHODSTo test this hypothesis, we used burn as a model of severe injury in which patients develop SIRS and coagulopathy without bleeding, allowing us to study the consequences of plasmin activation aside from hemorrhage. Thirty-one burn patients with >5% total body surface area (TBSA) burns admitted to the Vanderbilt University Medical Center Burn Unit were enrolled upon patient consent along with 10 healthy volunteers. Blood was collected serially for the length of hospital stay beginning upon admission. To study the clinical condition and control study variables, we administered a 30% TBSA burn to mice in a parallel study, collecting blood serially beginning at 1-hour post-burn (N=6/group). Control mice received similar preparation in the absence of a burn. Outputs assessed for humans and mice were the same. Plasma plasmin-antiplasmin complexes (PAPc) were used as a measure for plasmin activation, plasma IL-6, IL-1β, and TNFα were used to measure systemic inflammation, and plasma antithrombin III (ATIII) deficiency and platelet count were used to measure coagulopathy. To study the role of plasmin(ogen) in burn-induced coagulopathy and inflammation in a preliminary experiment, plasminogen+/- mice with 50% normal circulating plasminogen and plasmin activity received a similar burn. Both human and animal studies were previously approved by Vanderbilt University IRB and IACUC respectively. RESULTSIn burn patients without inhalation injury, PAPc levels significantly increased in proportion to the severity of injury measured by %TBSA (p<0.03). Additionally admission PAPc levels were inversely correlated with platelet nadir (R2=0.44, p<0.02) and directly correlated with peak IL-6 levels (R2=0.64, p<0.005) (Figure 1A-B). Patients with inhalation injuries did not exhibit significant correlations for these measurements. While ATIII deficiency was only detected in 4 out of 31 burn patients, burned mice exhibited a significant ATIII deficiency between 1 and 6 hours post-burn (p<0.01) compared with controls. In parallel with the human results, mice with burns developed a significant platelet deficiency and dramatically increased plasma PAPc and IL-6 levels at 24 hours post-burn(p<0.001). Early studies in Plg+/- mice demonstrated a markedly reduced peak plasma IL-6 levels post-burn (p<0.009) (Figure 1C). Changes in plasma IL-1β and TNFα were weakly sensitive to injury severity. CONCLUSIONStudies in severe injuries and elective surgeries have demonstrated that early inhibition of plasmin activation by antifibrinolytic drugs not only reduced bleeding, but also systemic inflammation. Our results suggest an association between plasmin activation, platelet loss, and systemic inflammation following burn injury in both human and mouse models. While the study in Plg+/- mice implicates plasmin in burn-induced inflammation, future studies will examine the mechanistic role of plasmin activation in burn-induced systemic inflammation and coagulopathy using genetic and pharmacologic tools to manipulate plasmin in a mouse model. While the systemic response to burn injury is similar to that of other severe injuries, future studies will investigate the relationship between plasmin activation, coagulopathy, and SIRS in general trauma. As a critical modulator of hemostasis and inflammation, our findings support plasmin as a potential therapeutic target for regulating trauma-induced coagulopathy and SIRS, beyond inhibition of fibrinolysis. [Display omitted] DisclosuresSchoenecker:OrthoPediatrics: Consultancy.

Platelet Drop and Fibrinolytic Shutdown in Patients With Sepsis.

Thrombocytopenia is the most common hemostatic disorder during sepsis and is associated with high mortality. We examined whether fibrinolytic changes precede incident thrombocytopenia and predict outcome in patients with severe sepsis. Nested study from the multicenter, randomized, controlled trial on the efficacy of albumin replacement in severe sepsis or septic shock (the Albumin Italian Outcome Sepsis trial). Forty ICUs in Italy. Three groups of patients were selected: 1) patients with platelet count less than or equal to 50 × 10/L at study entry (n = 85); 2) patients with baseline platelet count greater than or equal to 100 × 10/L who developed thrombocytopenia (≤ 50 × 10/L) within 28 days (n = 100); 3) patients with platelet count always more than or equal to 100 × 10/L (n = 95). Fibrinolytic variables, including fibrinolysis inhibitors and in vivo markers of plasmin generation, were measured on day 1. Patients with early thrombocytopenia (group 1) and those who developed it later (group 2) had similar illness severity and 90-day mortality, whereas patients without thrombocytopenia (group 3) had milder disease and lower mortality. Fibrinolysis was markedly (and similarly) depressed in groups 1 and 2 as compared with group 3. Major fibrinolytic changes included increased levels of plasminogen activator inhibitor 1 and extensive activation/consumption of thrombin activatable fibrinolysis inhibitor. Most fibrinolytic variables were significantly associated with mortality in univariate models. However, only thrombin activatable fibrinolysis inhibitor level and in vivo markers of fibrinolysis activation, namely plasmin-antiplasmin complex, and D-dimer, were independently associated with mortality after adjustment for Simplified Acute Physiology Score-II score, sex, and platelet count. Furthermore, the coexistence of impaired fibrinolysis and low platelets was associated with an even greater mortality. Impaired fibrinolysis, mainly driven by plasminogen activator inhibitor-1 increase and thrombin activatable fibrinolysis inhibitor activation, is an early manifestation of sepsis and may precede the development of thrombocytopenia. Thrombin activatable fibrinolysis inhibitor level, in particular, proved to be an independent predictor of mortality, which may improve risk stratification of patients with severe sepsis.

Association between uremic toxin-anthranilic acid and fibrinolytic system activity in predialysis patients at different stages of chronic kidney disease

PurposeChronic kidney disease (CKD) is an estimated risk factor for increased mortality and morbidity due to fibrinolytic system disturbances. Progressive loss of renal function leads to retention of uremic toxins. Anthranilic acid (AA) is a tryptophan-derived uremic toxin with multidirectional properties that can affect the hemostatic system. The goal of this study was to examine the association between AA and the parameters of fibrinolysis at different stages of CKD.MethodsPatients with CKD were divided into two groups: mild-to-moderate (n = 20) and severe-to-end-stage CKD (n = 28). Seventeen healthy volunteers served as an additional control group. Parameters of fibrinolysis, inflammation, and monocytes activation were determined by ELISA immune-enzymatic kits. AA levels were evaluated using high-performance liquid chromatography.ResultsAA concentration and parameters of fibrinolysis: urokinase-type plasminogen activator (uPA), its soluble receptor (suPAR), tissue plasminogen activator (tPA), tissue plasminogen activator inhibitor-1 (PAI-1) and plasmin-antiplasmin complex (PAP) were significantly elevated in the CKD groups compared with the controls. The markers of inflammation, monocyte activation, and impaired kidney function were also increased in those with CKD. AA was positively correlated with the uPA/suPAR system in the early stages of CKD, whereas during severe-to-end-stage CKD, inverse relationships were observed between AA, tPA and PAI-1. Additionally, AA was an independent variable associated with tPA in patients with CKD overall and with uPA levels in the mild-to-moderate CKD group.ConclusionsObtained results suggest for the first time the association between AA and the fibrinolytic system in CKD patients. The distinct relationship between AA and individual parameters of fibrinolysis appears to be dependent on CKD stage.

Colistin dampens fibrinolysis and endothelial activation during endotoxaemia

SummaryColistin electrostatically interacts with lipopolysaccharides (LPS). Preclinical studies demonstrated beneficial effects of colistin on LPS-induced coagulation and fibrinolysis. The objective of this trial was to investigate the effects of colistin during experimental endotoxaemia. In this randomised, double-blind, placebo-controlled, crossover trial 16 healthy volunteers received a 2 ng/kg LPS bolus after infusion of 2.5 million IU colistin or placebo. Plasma levels of F1+2 prothrombin fragments, thrombin-antithrombin complexes (TAT), von Willebrand factor antigen levels (vWF), E-selectin, plasmin-antiplasmin complexes (PAP), tissue-type plasminogen activator (t-PA) antigen and activity, plasminogen activator inhibitor-1 (PAI-1) were measured. Infusion of colistin significantly reduced peak concentrations of PAP complexes by 70 %, t-PA antigen levels by 63 % and t-PA activity by 48 %, while PAI-1 levels decreased numerically by 63 %. Two hours after the LPS bolus F1+2 levels and TAT complexes were slightly reduced in the colistin period, but peak concentrations were similar in both periods. Colistin blunted the LPS induced four-fold increase in soluble E-Selectin levels by ∼50 % and the two-fold increase in vWF antigen levels by ∼70 %. The LPS-scavenging actions of colistin significantly reduce endothelial activation and fibrinolytic response in the human endotoxaemia model, while the activation of the coagulation system remains largely unaffected.Note: This work was conducted at the Medical University of Vienna.EudraCT-Nr.: 2014–00285720 Supplementary Material to this article is available online at http://www.thrombosis-online.com

Research protocol for platelets in out-of-hospital cardiac arrest: an observational, case-controlled, feasibility study to assess coagulation and platelet function abnormalities with ROTEM following out-of-hospital cardiac arrest (PoHCAR)

IntroductionOut-of-hospital cardiac arrest (OHCA) has an annual incidence of approximately 60 000 in the UK. Less than 10% of those who receive resuscitation survive to hospital discharge. For OHCA of...

Altered preoperative coagulation and fibrinolysis are associated with myocardial injury after non-cardiac surgery

BackgroundMyocardial injury after non-cardiac surgery (MINS), a complication with unclear pathogenesis, occurs within the first 30 days after surgery and worsens prognosis. Hypercoagulability induced by surgery might contribute to plaque rupture, with subsequent thrombosis and myocardial injury. This study assessed haemostatic markers before surgery and evaluated their association with MINS. MethodsThis is a substudy of VISION, a prospective cohort study of perioperative cardiovascular events. Of 475 consecutive vascular surgery patients, 47 (9.9%) developed MINS, defined as postoperative high-sensitivity troponin ≥50 ng litre−1, with ≥20% elevation from the preoperative concentration. The control group consisted of 84 non-MINS patients matched for patient characteristics and co-morbidities. The following preoperative markers of hypercoagulability and fibrinolysis were measured: antithrombin, factor VIII activity, von Willebrand factor concentration and activity, fibrinogen, D-dimer, plasmin–antiplasmin complex, and tissue plasminogen activator. Moreover, C-reactive protein and CD40L concentrations were measured to assess inflammatory activity. ResultsPatients with MINS compared with the non-MINS group had a significantly higher concentration of factor VIII (186 vs 155%, P=0.006), von Willebrand factor activity (223 vs 160%, P<0.001), von Willebrand factor concentration (317 vs 237%, P=0.02), concentrations of fibrinogen (5.6 vs 4.2 g litre−1, P=0.03), D-dimer (1680.0 vs 1090.0 ng ml−1, P=0.04), plasmin–antiplasmin complex (747 vs 512 ng ml−1, P=0.002) and C-reactive protein (10 vs 4.5 mg litre−1, P=0.02) but not antithrombin (95 vs 94%, P=0.89), tissue plasminogen activator (11 vs 9.7 ng ml−1, P=0.06) and CD40L (8790 vs 8580 pg ml−1, P=0.73). ConclusionsPreoperative elevation of blood markers of hypercoagulability in patients undergoing vascular surgery is associated with a higher risk of MINS. Clinical trial registrationNCT00512109.

A case control study on the structural equation model of the mechanism of coagulation and fibrinolysis imbalance in chronic schistosomiasis.

A structural equation model was used for verification with chronic schistosomiasis to investigate the coagulation–anticoagulation system imbalance and to deduce the mechanism of D-dimer (D-D) level elevation in patients with advanced schistosome hepatic disease. We detected the plasma levels of tissue-type fiber plasminogen activator (tPA), urokinase type plasminogen activator (uPA), plasmin-antiplasmin complex (PAP), plasminogen (PLG), antithrombin (AT), plasminogen activator inhibitor 1 (PAI1), D-D, factor VIII: C (FVIII:C), antithrombin-III (AT-III), PLG, protein S (PS), and protein C (PC) in the healthy people as control (69), patients with chronic schistosomiasis (150) or advanced chronic schistosomiasis (90). FVIII, PAP, D-D, tPA, and uPA plasma levels were significantly higher in the chronic group than in the control group and were also significantly higher in the advanced group. However, AT-III, PC, PS, AT, PLG, and PAI1 plasma levels in the advanced and chronic groups were significantly lower than those in the control group. With progression of disease in patients with schistosomiasis japonica, a hypercoagulable state is induced by the coagulation–anticoagulation imbalance, eventually leading to patients with high levels of D-D. Furthermore, we established a structural equation model path of a “chronic schistosomiasis disease stage–(coagulation–anticoagulation–fibrinolysis)–D-D.” By using analysis of moment structures (AMOS), it was shown that the chronic schistosomiasis stage was positively related to factor VIII and had negative correlation with AT-III; a good positive correlation with PAP, tPA, and uPA; and a good negative correlation with PLG and PAI1. In addition, our results show that the path coefficient of anticoagulation–fibrinolysis system to the chronic stage of schistosomiasis or D-D levels was significantly higher than that of the coagulation system. In conclusion, the coagulation and fibrinolysis imbalance in patients with chronic schistosomiasis, especially with advanced schistosomiasis, is due to the progression of disease stages.

Activation of Fibrinolysis, But Not Coagulation, During End-Ischemic Ex Situ Normothermic Machine Perfusion of Human Donor Livers.

Ex situ normothermic machine perfusion (NMP) can be performed after traditional static cold preservation to assess graft function and viability before transplantation. It is unknown whether this results in activation of coagulation and fibrinolysis, as may occur upon graft reperfusion in vivo. Twelve donor livers declined for transplantation underwent 6 hours of end-ischemic NMP using a heparinized plasma-based perfusion fluid. Concentration of prothrombin fragment F1 + 2 (marker of coagulation activation), D-dimer, plasmin-antiplasmin complex, tissue plasminogen activator and plasminogen activator inhibitor-1 (markers for fibrinolysis) and alanine aminotransferase (ALT) (marker of ischemia-reperfusion [I/R] injury) were measured in perfusion fluid at regular intervals. Liver biopsies were examined for the presence of fibrin, using light microscopy after Maurits, Scarlet and Blue staining. No significant increase in prothrombin F1 + 2 was noted during NMP. D-dimer and plasmin-antiplasmin complex levels increased soon after start of NMP and D-dimer concentrations correlated significantly with levels of tissue plasminogen activator. In livers displaying good function during NMP, perfusate levels of ALT and D-dimers were low (≤3500 ng/mL), whereas significantly higher D-dimer levels (>3500 ng/mL) were in found in livers with poor graft function. Activation of fibrinolysis correlated significantly with the degree of I/R injury, as reflected by ALT levels. End-ischemic ex situ NMP results in activation of fibrinolysis, but not of coagulation. Markers of fibrinolysis activation correlate significantly with markers of I/R injury. High concentrations of D-dimer early after start of NMP can be considered a marker of severe I/R injury and a predictor of poor liver graft function.

Fibrin clot structure - pro-fibrinolytic effect of oral contraceptives in apparently healthy women.

Fibrin metabolism is influenced by many factors. The velocity of fibrin formation, genetic polymorphisms, fibrinolytic features and the structure of the fibrin clot are determinants of fibrin turnover. Oral contraceptives (OCs) have significant impact on the haemostatic system, by increasing the concentration of coagulation factors, plasminogen and tissue plasminogen activator activity, and decreasing the concentration of haemostatic inhibitors. The present study addresses the influence of OCs on fibrin structure and fibrin metabolism. The study included 70 women treated with seven different OC-formulations. Blood was collected at baseline and after six months of OCs. The plasma concentration of fibrinogen, thrombin-antithrombin complex (TAT), plasminogen, plasmin-antiplasmin complex (PAP), D-Dimer and thrombin generation measures were determined. Fibrin structure measures and fibrin clot lysis not affected by the plasma concentration of plasminogen activators and inhibitors were determined. OCs increased the concentration of fibrinogen, TAT, plasminogen, PAP and D-dimer significantly and affected measures of thrombin generation (p<0.001). The maximal optical density of fibrin (p<0.001), the fibrin fibre density (p=0.03), fibrin fibre diameter (p=0.003), fibrin mass-length ratio (p<0.001) and lysis per hour (p<0.001) increased significantly upon OC-treatment. Lysis per hour was not correlated to the concentration of plasminogen. We conclude that the effect of OCs on the coagulation system is balanced by alterations in fibrin structure, facilitating clot lysis and contributing to the fibrinolytic susceptibility already present in women treated with OC. These alterations may counterbalance the OC-induced increased thrombin generation and reduced coagulation inhibitory potential, contributing to maintenance of the haemostatic balance in women receiving OCs.

The Effects of Steroids on Coagulation Dysfunction Induced by Cardiopulmonary Bypass: A Steroids in Cardiac Surgery (SIRS) Trial Substudy

Cardiopulmonary bypass (CPB) surgery, despite heparin administration, elicits activation of coagulation system resulting in coagulopathy. Anti-inflammatory effects of steroid treatment have been demonstrated, but its effects on coagulation system are unknown. The primary objective of this study is to assess the effects of methylprednisolone on coagulation function by evaluating thrombin generation, fibrinolysis, and platelet activation in high-risk patients undergoing cardiac surgery with CPB. The Steroids In caRdiac Surgery study is a double-blind, randomized, controlled trial performed on 7507 patients worldwide who were randomized to receive either intravenous methylprednisolone, 250 mg at anesthetic induction and 250 mg at initiation of CPB (n = 3755), or placebo (n = 3752). A substudy was conducted in 2 sites to collect blood samples perioperatively to measure prothrombin fragment 1.2 (PF1+2, thrombin generation), plasmin-antiplasmin complex (PAP, fibrinolysis), platelet factor 4 (PF4 platelet activation), and fibrinogen. Eighty-one patients were enrolled in the substudy (37 placebo vs 44 in treatment group). No difference in clinical outcome was detected, including postoperative bleeding and need for blood products transfusion. All patients showed changes of all plasma biomarkers with greater values than baseline in both groups. This reaction was attenuated significantly in the treatment group for PF1.2 (P = 0.040) and PAP (P = 0.042) values at the first intraoperative measurement. No difference between groups was detected for PF4. Methylprednisolone treatment attenuates activation of coagulation system in high-risk patients undergoing CPB surgery. Reduction of thrombin generation and fibrinolysis activation may lead to reduced blood loss after surgery.

Blood coagulation biomarkers for postoperative venous thromboembolism diagnosis in orthopedic traumatic patients: a case control study

Objective To evaluate the value of blood coagulation biomarkers in orthopaedic traumatic patients after surgery and analyze its diagnostic values for venous thrombosis embolism. Methods In thiscase control study, we consecutive enrolled 108 traumatic patients after surgery. 54 patients have thrombosis and other 54 patients have no thrombosis. Blood was taken 3-4 days after surgery. Routine coagulation screening test , FDP(fibrinogen/fibrin degradation products) , D dimer and new item such as TM(thrombomodulin), TAT(thrombin-anti-thrombin complex), t-PAIC(tissue- type plasminogen activator-plasminogen activator inhibitor complex), PIC(plasmin-anti-plasmin complex) were tested. The difference between groups of these biomarkers was compared, and then the receiver operation curve (ROC) was drew to determine the diagnostic cut-off point and diagnostic performance. Results ALL blood coagulation biomarkers in orthopaedic traumatic patients after surgery were significantly increased. The group of patients with thrombosis have higher TM(9.04±2.06)IU/ml, t-PAIC(10.15±4.23)ng/ml, PIC(1.15±0.70)μg/ml, D dimer(5.31±5.10)ng/ml than group without thrombosis TM(7.50±1.70)IU/ml, t-PAIC (6.97±2.56)ng/ml, PIC(0.93±0.84)μg/ml, D dimer(2.35±2.12)ng/ml, and P=0.000 2, <0.000 1, <0.000 1, <0.000 1, respectively. However, TAT(4.79±4.32)ng/ml, (6.51±5.92)ng/ml, FDP(8.87±7.68)μg/ml, (4.91±4.67)μg/ml showed no difference between thrombosis groupand no thrombosis group, (P=0.212 3, 0.050 8; respectively). The area under the ROC curve of TM, t-PAIC, PIC and D-dimer were 0.718 5, 0.741 6, 0.648 0, 0.670 0, respectively; P values were <0.000 1, <0.000 1, 0.009 3, 0.004 1, respectively; cut-off values were 11.15 IU/ml, 10.65 ng/ml, 1.36 μg/ml, 7.69 ng/ml, respectively; positive likelihood ratios were 9.00, 11.29, 3.66, 14.60, respectively; specificity were 98.15%, 96.23%, 90.20%, 97.96%, respectively; the diagnostic rates were 20.3%, 46.3%, 35.8%, 25.9%, respectively. Conclusions There were coagulation and fibrinolysis system activated in orthopaedic traumatic patients after surgery.TM, t-PAIC, PIC, D dimer were good biomarkers for the diagnosis of thrombosis after trauma surgery. TAT was not fit for screening thrombosis after surgery because of influence of anti-coagulation.(Chin J Lab Med, 2016, 39: 751-755) Key words: Postoperative complications; Venous thrombosis; Biological markers; Thrombomodulin; Tissue plasminogen activator; Fibrin fibrinogen degradation products

The hemostatic disturbance in patients with acute aortic dissection: A prospective observational study.

Coagulopathy is still a frequent complication in the surgical treatment of acute aortic dissection. However, the physiopathology of surgically induced coagulopathy has never been systematically and comprehensively studied in patients with acute aortic dissection. The aim of the present study was to describe the perioperative hemostatic system in patients with acute aortic dissection.The 87 patients who underwent aortic arch surgery for acute Stanford type A aortic dissection from January 2013 to September 2015 were enrolled in this study. The perioperative biomarkers of hemostatic system were evaluated using standard laboratory tests and enzyme-linked immunosorbent assays (ELISAs) at 5 time points: anesthesia induction (T1), lowest nasopharyngeal temperature (T2), protamine reversal (T3), 4 hours after surgery (T4), and 24 hours after surgery (T5).The ELISAs biomarkers revealed activation of coagulation (thrombin-antithrombin III complex [TAT] and prothrombin fragment 1 + 2 [F1 + 2] were elevated), suppression of anticoagulation (antithrombin III [AT III] levels were depressed), and activation of fibrinolysis (plasminogen was decreased and plasmin-antiplasmin complex [PAP] was elevated). The standard laboratory tests also demonstrated that surgery resulted in a significant reduction in platelet counts and fibrinogen concentration.Systemic activation of coagulation and fibrinolysis, and inhibition of anticoagulation were observed during the perioperative period in patients with acute aortic dissection. Indeed, these patients exhibited consumption coagulopathy and procoagulant state perioperatively. Therefore, we believe that this remarkable disseminated intravascular coagulation (DIC)-like coagulopathy has a high risk of bleeding and may influence postoperative outcome of patients with acute aortic dissection.

An in vitro study of the effects of t-PA and tranexamic acid on whole blood coagulation and fibrinolysis

AimsAcute traumatic coagulopathy is characterised by fibrinolysis and low fibrinogen. It is unclear how much fibrinogenolysis contributes to reduce fibrinogen levels. The study aim was to: investigate in vitro the...

Blockade of Extracellular High-Mobility Group Box 1 Attenuates Systemic Inflammation and Coagulation Abnormalities in Rats with Acute Traumatic Coagulopathy

BackgroundAs an extracellularly released mediator, high-mobility group box 1 (HMGB1) initiates sterile inflammation following severe trauma. Serum HMGB1 levels correlate well with acute traumatic coagulopathy (ATC) in trauma patients, which is independently associated with higher mortality. We investigated the involvement of HMGB1 in ATC through blocking extracellular HMGB1.Material/MethodsThe ATC model was induced by polytrauma and hemorrhage in male Sprague-Dawley rats, which were randomly assigned to sham, ATC, and ATCH (ATC with HMGB1 blockade) groups. Thrombelastography (TEG) was performed to monitor changes in coagulation function. Serum levels of HMGB1, TNF-α, and IL-6 were measured, as well as lung levels of HMGB1 and nuclear factor (NF)-κB and expression of receptor for advanced glycation end-products (RAGE).ResultsCompared with the sham group, HMGB1 increased the serum levels of TNF-α and IL-6, whereas HMGB1 blockade inhibited the induction of TNF-α and IL-6. HMGB1 also induced elevated serum soluble P-selectin and fibrinolysis markers plasmin-antiplasmin complex, which both were reduced by HMGB1 blockade. Thrombelastography revealed the hypocoagulability status in the ATC group, which was attenuated by anti-HMGB1 antibody. Furthermore, the lung level of NF-κB and expression of RAGE were decreased by anti-HMGB1 antibody, suggesting the role of RAGE/NF-κB pathway in ATC.ConclusionsHMGB1 blockade can attenuate inflammation and coagulopathy in ATC rats. Anti-HMGB1 antibody might exert protective effects partly through the RAGE/NF-κB pathway. Thus, HMGB1 has potential as a therapeutic target in ATC.