Activated Coagulation Factor Research Articles

Economic and Humanistic Burden of Moderate and Severe Hemophilia A and B in Spain: Real-World Evidence Insights from the CHESS II Study

Background: Hemophilia is a congenital disorder characterized by deficiency or absence of clotting factor VIII in hemophilia A (HA) or clotting factor IX in hemophilia B (HB), resulting in frequent, repeated, and prolonged spontaneous or traumatic bleeding into joints or soft tissue. Severity is classified by the patient's baseline level of clotting factor activity as mild (>5%-40%), moderate (1%-5%), or severe (<1%). In Spain, there is limited information on the societal economic burden of disease. Objective: To estimate the economic and humanistic burden of disease in adult patients with non-inhibitor moderate and severe HA and HB in Spain. Methods: Spanish data from the CHESS II study (2018-2020) on patients' clinical characteristics, health-related quality of life (HRQoL) and hemophilia-related healthcare resource utilization were analyzed. Economic burden was determined by estimating condition-related annual per-patient direct (medical and nonmedical) and indirect costs, stratified according to hemophilia type and severity and presented as 2022 Euros. HRQoL was assessed via the EQ-5D-5L. Results: Of 341 patients in the Spanish CHESS II cohort, 288 patients met the inclusion criteria: 181 had HA (37% [n = 66] moderate and 63% [n=115] severe) and 107 had HB (26% [n = 28] moderate and 74% [n = 79] severe). Mean annual direct cost was higher in HB than in HA, and higher in severe than in moderate patients, resulting in an annual cost/patient of €17 251 (moderate HA), €17 796 (moderate HB), €116 767 (severe HA) and €206 996 (severe HB). The main direct cost component in all groups except moderate HA was factor replacement therapy. Mean per-patient indirect cost was €4089 (moderate HA), €797 (moderate HB), €8633 (severe HA) and €8049 (severe HB). Finally, the mean total cost (direct and indirect) for moderate and severe patients were €91 017 (HA) and €163 924 (HB). EQ-5D-5L [SD] scores were lower in patients with severe HA (0.77 [0.18]) and severe HB (0.70 [0.22]) compared with patients with moderate HA (0.81 [0.15]) and moderate HB (0.86 [0.17]). Conclusions: Independently of the type of hemophilia, greater condition severity was associated with increased costs and a decrease in HRQoL.

9 Differential Coagulation Factor Activity in Obese vs. Non-Obese Burn Injured Patients

9 Differential Coagulation Factor Activity in Obese vs. Non-Obese Burn Injured Patients

Development of an efficient hemostatic material based on cuttlefish ink nanoparticles loaded in cuttlebone biocomposite.

Traumatic hemorrhage is one of the main causes of mortality in civilian and military accidents. This study aimed to evaluate the effectiveness of cuttlefish bone (cuttlebone, CB) and CB loaded with cuttlefish ink (CB-CFI) nanoparticles for hemorrhage control. CB and CB-CFI were prepared and characterized using different methods. The hemostasis behavior of constructed biocomposites was investigated in vitro and in vivo using a rat model. Results showed that CFI nanoparticles (NPs) are uniformly dispersed throughout the CB surface. CB-CFI10 (10 mg CFI in 1.0 g of CB) showed the best blood clotting performance in both in vitro and in vivo tests. In vitro findings revealed that the blood clotting time of CB, CFI, and CB-CFI10 was found to be 275.4 ± 12.4 s, 229.9 ± 19.9 s, and 144.0 ± 17.5 s, respectively. The bleeding time in rat liver injury treated with CB, CFI, and CB-CFI10 was 158.1 ± 9.2 s, 114.0 ± 5.7 s, and 46.8 ± 2.7 s, respectively. CB-CFI10 composite resulted in more reduction of aPTT (11.31 ± 1.51 s) in comparison with CB (17.34 ± 2.12 s) and CFI (16.79 ± 1.46 s) (p < 0.05). Furthermore, CB and CB-CFI10 exhibited excellent hemocompatibility. The CB and CB-CFI did not show any cytotoxicity on human foreskin fibroblast (HFF) cells. The CB-CFI has a negative surface charge and may activate coagulation factors through direct contact with their components, including CaCO3, chitin, and CFI-NPs with blood. Thus, the superior hemostatic potential, low cost, abundant, simple, and time-saving preparation process make CB-CFI a very favorable hemostatic material for traumatic bleeding control in clinical applications.

Clinical Analysis and Mental Health Survey of Hemophilia Carriers: a Cross-sectional Study.

Hemophilia carriers (HCs), who are heterozygous for mutations in the clotting factor VIII/clotting factor IX gene (F8 or F9), may have a wide range of clotting factor levels, from very low, similar to afflicted males, to the upper limit of normal, and may experience mental health issues. The purpose of this study was to provide genetic information on mothers of hemophilia patients and to understand the clotting factor activity and phenotype of HCs. Additionally, we aimed to investigate the mental health status of HCs in China. A total of 127 hemophilia mothers, including 93 hemophilia A (HA) mothers and 34 hemophilia B (HB) mothers, were enrolled in this study. Long distance PCR, multiplex PCR, and Sanger sequencing were used to analyze mutations in F8 or F9. Coagulation factor activity was detected by a one-stage clotting assay. The Symptom Checklist 90 (SCL-90, China/Mandarin version) was given to HCs at the same time to assess their mental health. A total of 90.6% of hemophilia mothers were diagnosed genetically as carriers, with inversion in intron 22 and missense mutations being the most common mutation types in HA and HB carriers, respectively. The median clotting factor level in carriers was 0.74 IU/mL (ranging from 0.09 to 1.74 IU/mL) compared with 1.49 IU/mL (ranging from 0.93 to 1.89 IU/mL) in noncarriers, of which 14.3% of HCs had clotting factor levels of 0.40 IU/mL or below. A total of 53.8% (7/13) of HA carriers with low clotting factor levels (less than 0.50 IU/mL) had a history of bleeding, while none of the HB carriers displayed a bleeding phenotype. The total mean score and the global severity index of the SCL-90 for surveyed HCs were 171.00 (±60.37) and 1.78 (±0.59), respectively. A total of 67.7% of the respondents had psychological symptoms, with obsessive-compulsive disorder being the most prevalent and severe. The pooled estimates of all nine factors were significantly higher than those in the general population (P<0.05). The detection rate of gene mutations in hemophilia mothers was 90.6%, with a median clotting factor level of 0.74 IU/mL, and 14.3% of HCs had a clotting factor level of 0.40 IU/mL or below. A history of bleeding was present in 41.2% of HCs with low clotting factor levels (less than 0.50 IU/mL). Additionally, given the fragile mental health status of HCs in China, it is critical to develop efficient strategies to improve psychological well-being.

Acquired bleeding disorders

Acquired bleeding disorders can develop in previously healthy people irrespective of age or gender but are particularly common in patients with certain underlying conditions. Here, we review recent advances in the management of acquired haemophilia A (AHA), acquired von Willebrand syndrome (AVWS), and patients with hemostatic abnormalities due to chronic liver disease (CLD). Patients with AHA can now benefit from prophylaxis with emicizumab, a therapeutic antibody that mimics the function of activated coagulation factor VIII. The treatment of AVWS remains challenging in many situations and requires careful consideration of the underlying condition. Haemostatic abnormalities in CLD are often compensated by proportional reduction in pro and anti-haemostatic factors resulting in sustained or even increased thrombin generation. Consequently, bleeding in CLD is rarely caused by haemostatic failure and infusion of plasma or coagulation factor concentrates may not be effective.

Molecular and clinical profile of rare bleeding disorders: A single-center retrospective study

IntroductionDue to their low frequency, there is little information on the molecular pathologies of rare bleeding disorders (RBD). Therefore, this study aimed to analyze the molecular and clinical profiles of patients with RBD. MethodsA retrospective single-center study was conducted among patients with factor (F) II, FVII, FX, and FXIII deficiencies between March 20, 2000, and June 31, 2023. Data on patient demographics, genetic analysis, and laboratory results were documented for all patients. The disease severity was classified according to the clotting factor activity (except FXIII) as follows: >5%: mild, 1-5%: moderate, and <1%: severe. ResultsA total of 79 patients were enrolled in this study. Three of the cases had FII (3.7%), 40 had FVII (50.6%), 20 had FX (25.3%), and 16 had FXIII deficiency (20.2%). The median age of the patients at the time of diagnosis was six months for FII, 6.5 years for FVII, five months for FX, and 5.75 months for FXIII deficiencies, respectively. The major clinical manifestations were bruising, epistaxis, oral cavity bleeding, ecchymosis, and hemarthrosis. Consanguinity was present in 60 (76%) of patients. The majority of the patients had missense mutations. FVII mutations occurred primarily in exon 6, FX mutations affected mainly exons 2 and 7, and the majority of FXIII mutations occurred in exons 3 and 4. ConclusionThe diagnosis of the causative mutations in patients with RBD provides an insight into the underlying molecular basis of these disorders and probably explains their variable clinical manifestations.

Impact of therapeutic plasma exchange on intact protein S, apolipoproteins, and thrombin generation

IntroductionTherapeutic plasma exchange (TPE), with solvent/detergent (S/D)-treated plasma as replacement fluid, is an extracorporeal blood purification technique with major impact on both coagulation and lipids. Our previous in vitro study showed that S/D-plasma enhances thrombin generation by lowering intact protein S (PS) levels. Aims: To evaluate the impact of altered lipid balance on coagulation phenotype during heparin-anticoagulated TPE with S/D-plasma, and to investigate whether the lowered intact PS levels with concomitant procoagulant phenotype, are recapitulated in vivo. Methods: Coagulation biomarkers, thrombin generation with Calibrated Automated Thrombogram (CAT), and lipid levels were measured before and after the consecutive 1st, 3rd and 5th episodes of TPE performed to six patients with Guillain-Barré syndrome or myasthenia gravis. The effects of in vitro dilution of S/D-plasma on thrombin generation were explored with CAT to mimic TPE. Results: Patients did not have coagulation disorders, except elevated FVIII. Intact PS, lipoproteins, especially LDL, Apolipoprotein CIII (ApoC3) and ApoB/ApoA1 ratio declined (p < 0.05). In contrast, VLDL and triglyceride levels stayed intact. CAT lag time shortened (p < 0.05). In vitro dilution of S/D plasma with co-transfused Ringer's lactate and 4% albumin partially reduced its procoagulant phenotype in CAT, which is mainly seen as peak thrombin, and modestly shortened lag time. Conclusions: After the five settings of TPE using S/D-plasma in vivo, which associated with heparinization and reduced coagulation factor activities, our observations of declining natural anticoagulant intact PS and apolipoproteins refer to rebalance of the hemostatic and lipid profiles.

[Anticoagulant rodenticide poisoning in dogs: Retrospective analysis of clinical and laboratory diagnostic data].

In this retrospective study, patient records of dogs suffering from poisoning with coumarin derivatives were evaluated to characterize the clinical appearance more precisely. Retrospective data analysis included 52 dogs with hemostaseologically proven anticoagulant rodenticide poisoning which were treated as inpatients at the Clinic for Small Animals between September 2011 and October 2018. In only 2 dogs (4%) the intake of poison could be observed with certainty. The most common clinical signs observed were reduced general behavior (79%), pallor of the mucosa (79%), anorexia (60%), and dyspnea/tachypnea (60%). In contrast, macroscopically visible internal and external bleedings occurred less frequently. Initially, all cases showed a highly altered prothrombin time and most patients a considerably prolonged activated partial thromboplastin time. Anemia was present in 75% of patients. All dogs included in the study received initially an intravenous treatment with 10 mg/kg vitamin K1. Pretreatment with 1 mg/kg prednisolone was given for prophylaxis of possible incompatibility reactions. No patient showed signs of anaphylactic reaction. Transfusions of whole blood or concentrated red cells were given to only 10 of the 52 animals; only one received 2 transfusions of erythrocytes. 94% of the animals could be discharged home for outpatient therapy after a median length of hospitalization of 3 days (1-9 days) with physiological or almost physiological coagulation test results. Anticoagulant rodenticide poisoning is often associated with non-specific symptoms and good prognosis if treated adequately. Coagulation diagnostics is always indicated in cases with unclear disorders. In life-threatening emergencies, immediate intravenous infusion of high-dose vitamin K1 is a very effective treatment and results in a rapid increase in coagulation factor activity.

The effects of polysaccharide size of lipopolysaccharide from E. coli on the binding and activation of coagulation factor XII

The effects of polysaccharide size of lipopolysaccharide from E. coli on the binding and activation of coagulation factor XII

A bispecific antibody approach for the potential prophylactic treatment of inherited bleeding disorders

Inherited bleeding disorders such as Glanzmann thrombasthenia (GT) lack prophylactic treatment options. As a result, serious bleeding episodes are treated acutely with blood product transfusions or frequent, repeated intravenous administration of recombinant activated coagulation factor VII (rFVIIa). Here we describe HMB-001, a bispecific antibody designed to bind and accumulate endogenous FVIIa and deliver it to sites of vascular injury by targeting it to the TREM (triggering receptor expressed on myeloid cells)-like transcript-1 (TLT-1) receptor that is selectively expressed on activated platelets. In healthy nonhuman primates, HMB-001 prolonged the half-life of endogenous FVIIa, resulting in its accumulation. Mouse bleeding studies confirmed antibody-mediated potentiation of FVIIa hemostatic activity by TLT-1 targeting. In ex vivo models of GT, HMB-001 localized FVIIa on activated platelets and potentiated fibrin-dependent platelet aggregation. Taken together, these results indicate that HMB-001 has the potential to offer subcutaneous prophylactic treatment to prevent bleeds in people with GT and other inherited bleeding disorders, with a low-frequency dosing regimen.

Efficacy and Safety of Adeno-Associated Virus-Based Clinical Gene Therapy for Hemophilia: A Systematic Review and Meta-Analysis.

Clinical trials of adeno-associated virus (AAV)-based gene therapy have made remarkable progress in recent years. We aimed to perform a systematic review and meta-analysis of the literature to assess the efficacy and safety of AAV-based gene therapy for hemophilia. We systematically searched the Web of Science, Embase, PubMed, and the Cochrane Database of Systematic Reviews databases, for clinical trials involving patients diagnosed with hemophilia and treated with AAV-mediated gene therapy. Data on the annualized bleeding rate (ABR), annualized infusion rate (AIR), the incidence of treatment-related adverse events (TRAEs), severe adverse events (SAEs), and alanine aminotransferase (ALT) elevation were extracted as our outcomes. A total of 12 articles from 11 clinical trials were selected from 868 articles for meta-analysis. Pooled analyses showed that AAV-based gene therapy in hemophilia patients reduced the number of bleeding events and the number of factor infusion events by an approximate average of 7 per year and 103 per year, respectively. Eighty percent, 18%, and 63% of hemophilia patients had elevated TRAE, SAE, and ALT levels, respectively. Moreover, subgroup analysis found a significant reduction in ABR and AIR 2-3 years after the therapy. Additional findings that were not pooled including coagulation factor activity are presented in the accompanying tables. Our analysis supported the efficacy and safety of AAV-mediated gene therapy for hemophilia, providing evidence for its application as a therapeutic option for widespread clinical use in hemophilia patients in the future.

Associations between coagulation factors and livedoid vasculopathy and the efficacy and safety of rivaroxaban in patients with livedoid vasculopathy: a retrospective study.

The mechanism of livedoid vasculopathy (LV) remains unknown. To investigate the association between coagulation factors and LV and to assess the efficacy and safety of rivaroxaban in the treatment of patients with LV. From May 2019 to July 2022, 89 LV patients and 35 healthy controls were included in the cross-sectional cohort to measure the levels of coagulation factors. In addition, 55 LV patients treated with rivaroxaban were included in the treatment cohort to assess the complete remission rate of ulcers (n=44) and retiform purpura (n=11) within 12 weeks. In the cross-sectional cohort, the activities of coagulation factor X in LV patients were significantly higher than healthy controls (median [IQR]: 110.5% [97.5-127.0%] vs 101.3% [91.6-115.6%]; P=0.047). In addition, the coagulation factor X activities in the progressive stage were higher than in the stable stage (median [IQR]: 111.6% [102.3-132.5%] vs 105.4% [92.9-118.8%]; P=0.037). Moreover, the coagulation factor X activities were higher in the progressive stage than in the stable stage in the paired LV patients (P=0.035). In the treatment cohort of rivaroxaban, 90.9% (40/44) of patients with ulcers achieved complete remission within 12 weeks, and 72.7% (8/11) of patients with retiform purpura achieved complete remission within 12 weeks. Mild side effects occurred in 25.5% of patients, including menorrhagia (n=10), gingival bleeding (n=3), and hemorrhage (n=1). It was demonstrated that coagulation factor X was associated with the incidence and severity of LV. In addition, rivaroxaban was an effective and safe treatment for ulcers and retiform purpura of LV.

The intrinsic coagulation pathway plays a dominant role in driving hypercoagulability in ANCA-associated vasculitis

AbstractThe risk of a venous thrombotic event (VTE) is increased in patients with antineutrophil cytoplasmic antibody (ANCA)–associated vasculitis (AAV); however, a detailed understanding of the underlying mechanisms of hypercoagulability is limited. We assessed prospectively different coagulation parameters in 71 patients with active AAV at baseline and after 6 months of follow-up. D-dimers and fibrinogen were increased in most patients at presentation and remained elevated in half of the patients. Particularly, thrombin-antithrombin (T:AT) complex and activated coagulation factors in complex with their natural inhibitors of the intrinsic coagulation pathway (ie, activated FXII:C1 esterase inhibitor [FXIIa:C1Inh], FXIa:AT, and FXIa:alpha1-antitrypsin [FXIa:α1AT]) were profoundly elevated in patients at baseline. Thrombin formation was dominantly correlated with coagulation factors of the intrinsic pathway (ie, FXIIa:AT, FXIa:AT, FXIa:α1AT, and FXIa:C1Inh) compared to the extrinsic pathway (ie, FVIIa:AT). Hypercoagulability correlated with higher disease activity, ANCA levels, C-reactive protein, serum creatinine, and proteinuria. VTEs were observed in 5 out of 71 (7%) patients within 1 month (interquartile range, 1-5) after inclusion. Baseline T:AT levels were significantly higher in patients with VTE than in those without VTE (P = .044), but other clinical or laboratory markers were comparable between both groups. Hypercoagulability is dominantly characterized by activation of the intrinsic coagulation pathway and elevated D-dimers in active AAV. The driving factors of hypercoagulability are yet to be studied but are most likely related to an interplay of increased disease activity, vascular inflammation, and endothelial damage. Future targets for intervention could include inhibitors of the intrinsic coagulation pathway and compounds specifically reducing the hyperinflammatory state.

Dabigatran pharmacokinetic-pharmacodynamic in sheep: Informing dose for anticoagulation during cardiopulmonary bypass.

The effect of the anticoagulant, dabigatran, and its antagonist, idarucizumab, on coagulation remains poorly quantified. There are few pharmacokinetic-pharmacodynamic data available to determine dabigatran dose in humans or animals undergoing cardiopulmonary bypass. Five sheep were given intravenous dabigatran 4mg/kg. Blood samples were collected for thromboelastometric reaction time (R-time) and drug assay at 5, 15, 30, 60, 120, 240, 480min, and 24h. Plasma dabigatran concentrations and R-times were analyzed using an integrated pharmacokinetic-pharmacodynamic model using non-linear mixed effects. The impact of idarucizumab 15mg/kg administered 120min after dabigatran 4mg/kg and its effect on R-time was observed. A 2-compartment model described dabigatran pharmacokinetics with a clearance (CL 0.0453L/min/70kg), intercompartment clearance (Q 0.268L/min/70kg), central volume of distribution (V1 2.94L/70kg), peripheral volume of distribution (V2 9.51L/70kg). The effect compartment model estimates for a sigmoid EMAX model using Reaction time had an effect site concentration (Ce50 64.2mg/L) eliciting half of the maximal effect (EMAX 180min). The plasma-effect compartment equilibration half time (T1/2keo) was 1.04min. Idarucizumab 15mg/kg reduced R-time by approximately 5min. Dabigatran reversibly binds to the active site on the thrombin molecule, preventing activation of coagulation factors. The pharmacologic target concentration strategy uses pharmacokinetic-pharmacodynamic information to inform dose. A loading dose of dabigatran 0.25mg/kg followed by a maintenance infusion of dabigatran 0.0175mg/kg/min for 30min and a subsequent infusion dabigatran 0.0075mg/kg/min achieves a steady state target concentration of 5mg/L in a sheep model.

Economic and Humanistic Burden of Moderate and Severe Hemophilia A and B in Spain: Real-World Evidence Insights from the CHESS II Study.

Background: Hemophilia is a congenital disorder characterized by deficiency or absence of clotting factor VIII in hemophilia A (HA) or clotting factor IX in hemophilia B (HB), resulting in frequent, repeated, and prolonged spontaneous or traumatic bleeding into joints or soft tissue. Severity is classified by the patient's baseline level of clotting factor activity as mild (>5%-40%), moderate (1%-5%), or severe (<1%). In Spain, there is limited information on the societal economic burden of disease. Objective: To estimate the economic and humanistic burden of disease in adult patients with non-inhibitor moderate and severe HA and HB in Spain. Methods: Spanish data from the CHESS II study (2018-2020) on patients' clinical characteristics, health-related quality of life (HRQoL) and hemophilia-related healthcare resource utilization were analyzed. Economic burden was determined by estimating condition-related annual per-patient direct (medical and nonmedical) and indirect costs, stratified according to hemophilia type and severity and presented as 2022 Euros. HRQoL was assessed via the EQ-5D-5L. Results: Of 341 patients in the Spanish CHESS II cohort, 288 patients met the inclusion criteria: 181 had HA (37% [n = 66] moderate and 63% [n=115] severe) and 107 had HB (26% [n = 28] moderate and 74% [n = 79] severe). Mean annual direct cost was higher in HB than in HA, and higher in severe than in moderate patients, resulting in an annual cost/patient of €17 251 (moderate HA), €17 796 (moderate HB), €116 767 (severe HA) and €206 996 (severe HB). The main direct cost component in all groups except moderate HA was factor replacement therapy. Mean per-patient indirect cost was €4089 (moderate HA), €797 (moderate HB), €8633 (severe HA) and €8049 (severe HB). Finally, the mean total cost (direct and indirect) for moderate and severe patients were €91 017 (HA) and €163 924 (HB). EQ-5D-5L [SD] scores were lower in patients with severe HA (0.77 [0.18]) and severe HB (0.70 [0.22]) compared with patients with moderate HA (0.81 [0.15]) and moderate HB (0.86 [0.17]). Conclusions: Independently of the type of hemophilia, greater condition severity was associated with increased costs and a decrease in HRQoL.

Phosphatidylthreonine is a procoagulant lipid detected in human blood and elevated in coronary artery disease

Aminophospholipids (aPL) such as phosphatidylserine are essential for supporting the activity of coagulation factors, circulating platelets, and blood cells. Phosphatidylthreonine (PT) is an aminophospholipid previously reported in eukaryotic parasites and animal cell cultures, but not yet in human tissues. Here, we evaluated whether PT is present in blood cells and characterized its ability to support coagulation. Several PT molecular species were detected in human blood, washed platelets, extracellular vesicles, and isolated leukocytes from healthy volunteers using liquid chromatography–tandem mass spectrometry. The ability of PT to support coagulation was demonstrated in vitro using biochemical and biophysical assays. In liposomes, PT supported prothrombinase activity in the presence and absence of phosphatidylserine. PT nanodiscs strongly bound FVa and lactadherin (nM affinity) but poorly bound prothrombin and FX, suggesting that PT supports prothrombinase through recruitment of FVa. PT liposomes bearing tissue factor poorly generated thrombin in platelet poor plasma, indicating that PT poorly supports extrinsic tenase activity. On platelet activation, PT is externalized and partially metabolized. Last, PT was significantly higher in platelets and extracellular vesicle from patients with coronary artery disease than in healthy controls. In summary, PT is present in human blood, binds FVa and lactadherin, supports coagulation in vitro through FVa binding, and is elevated in atherosclerotic vascular disease. Our studies reveal a new phospholipid subclass, that contributes to the procoagulant membrane, and may support thrombosis in patients at elevated risk.

No Detectable Coagulation Activation After Vitamin K (MK-7) Supplementation in Patients on Dialysis With Functional Vitamin K Deficiency: A One-Year Randomized, Placebo-Controlled Study

Patients on dialysis treatment have poor functional vitamin K status, and this may increase the risk of vascular calcification. Vitamin K supplementation may therefore be relevant in patients on dialysis, but the procoagulant effects have not been studied. We evaluated effects of menaquinone-7 (MK-7) supplementation on biomarkers of coagulation in patients on dialysis. Double-blinded, placebo-controlled study in 123 patients on dialysis randomized to 52weeks of vitamin K (MK-7, 360μg/daily, n=61) or placebo (n=62). Measurements at baseline and after 52weeks of intervention included thrombin generation (endogenous thrombin potential, peak thrombin concentration, time to peak, and lag time); clot activities of vitamin K-dependent coagulation factors (F) II, VII, IX, and X; prothrombin fragment 1+2 (F1+2); and proteins induced by vitamin K absence II (PIVKA-II). Between-group differences (vitamin K vs. placebo) at 52weeks were determined with an analysis of covariance. Within-group changes in vitamin K and placebo groups were analyzed with a paired t-test. Vascular adverse events and serious adverse events were registered based on hospital records, laboratory data, and participant interviews and compared between groups using Fisher's exact test or Pearson's Chi-Squared test. A between-group difference at 52weeks was observed for PIVKA-II (P<.001). PIVKA-II decreased significantly from baseline to 52weeks in the vitamin K group, but not in the placebo group. We observed no between-group differences or within-group changes for biomarkers of coagulation, except for FVII clot activity which was reduced in the placebo group (P=.04), and no between-group differences in adverse events and serious adverse events. One year of vitamin K supplementation in patients on dialysis has no detectable effects on biomarkers of coagulation activation, clot activities of vitamin K-dependent coagulation factors, and vascular events or death, indicating no procoagulant effects of this treatment.

Effect of cardiopulmonary bypass on coagulation factors II, VII and X in a primate model: an exploratory pilot study.

The use of cardiopulmonary bypass (CPB) in cardiac surgery is a major risk factor for postoperative bleeding. We hypothesized that consumptive coagulopathy and haemodilution influence the coagulation factors; therefore, we aimed to estimate the activity profiles of coagulation factors II, VII and X during CPB circulation. A 120-min bypass was surgically established in cynomolgus monkeys (n = 7). Activities of coagulation factors II, VII and X were measured at 6 time points during the experiment (baseline, 0, 30, 60, 120 min of bypass and 60 min after bypass). To assess the influence of consumptive coagulopathy, the values were adjusted for haemodilution using the haematocrit values. Data were expressed as mean (standard deviation). Activities of coagulation factors decreased during the experiment. In particular, the activities for II, VII and X were decreased the most by 44.2% (5.0), 61.4% (4.3) and 49.0% (3.7) at 30 min following CPB initiation (P < 0.001, P < 0.001 and P < 0.001, respectively). Following adjustments for haemodilution, change magnitudes lessened but remained significant for factor VII. The adjusted concentration of factor VII was observed to decrease from the baseline to the initiation of bypass circulation. In conclusion, coagulation factor II, VII and X concentrations decreased during CPB. Following adjustment for haemodilution, a decrease in concentration was observed with factor VII.

Time for a Paradigm Shift in Vitamin K Antagonist Reversal - Embracing TGA over INR for Optimal Outcomes?

Introduction: Vitamin K antagonist (VKA) anticoagulation reversal has relied on International Normalized Ratio (INR) as a standard parameter of coagulation status. Reversal of anticoagulation within INR ranges of 2 - 3 is usually achieved by 25 IU/kg of 4-Factor PCC (4F-PCC), resulting in INR &amp;lt;1.5. However, emerging evidence suggests that increases in coagulation factor activities may be more accurately reflected by the thrombin generation assay (TGA), paving the way for a different approach to assessing effectiveness of VKA reversal. To this effect, a Phase I/II clinical study was conducted to assess dose response of 4F-PCC in healthy subjects anticoagulated with a VKA agent. Methods: This was a prospective, randomized, open-label, placebo-controlled study involving healthy subjects aged 18 to 55 years. Participants were pre-treated for 10 days with acenocoumarol to achieve an INR between 2 and 3 (± 10% inclusive). Subsequently, they received a single iv bolus of 4F-PCC at doses of 12.5 IU/kg or 25 IU/kg, or placebo. Blood samples for TGA, INR, and blood clotting factors (FII, FVII, FIX, FX, protein C, and protein S) were assessed at specified intervals from pre-dose VKA (baseline) up to 15 days after 4F-PCC dose. Results: VKA for 10 days decreased plasma activities of blood clotting factors II, VII, IX and X as expected. Thirty minutes after infusion with 4F-PCC, clotting factor levels were increased in a dose-dependent manner, relative to pre-infusion levels. Placebo had no significant effect on any of the clotting factors. 4F-PCC at 12.5 IU/kg, or 25 IU/kg decreased mean INR values within 30 min after dosing from 2.39 to 1.37, and 2.45 to 1.17, respectively. Infusion with 25 IU/kg fully restored peak thrombin generation at 30 min after dosing compared to baseline (mean ratio: 1.08), while 12.5 IU/kg achieved partial restoration (mean ratio: 0.75). Factor II: Doses of 12.5 IU/kg or 25 IU/kg 4F-PCC increased mean FII values at 30 min post-dose from 32% to 65% and 32% to 89%, respectively (Figure 1). The median maximum concentration (Emax 0-12h) was 68% for 12.5 IU/kg, and 92% for 25 IU/kg (Table 1). Factor VII: Doses of 12.5 IU/kg and 25 IU/kg 4F-PCC increased mean FVII values at 30 min from 15% to 30%, and from 14% to 46%, respectively. The median Emax 0-12h was 32% for 12.5 IU/kg, and 46% for 25 IU/kg. Factor IX: Doses of 12.5 IU/kg and 25 IU/kg 4F-PCC increased mean FIX values at 30 min from 29% to 41% and from 29% to 52%, respectively. The median Emax 0-12h was 45% for 12.5 IU/kg, and 56% for 25 IU/kg. Factor X: Doses of 12.5 IU/kg and 25.0 IU/kg 4F-PCC increased mean FX values at 30 min, from 18% to 42% and 18% to 64%, respectively. The median Emax 0-12h was 45% for 12.5 IU/kg, and 66% for 25 IU/kg. Conclusion: After 4F-PCC infusion, clotting factors II, VII, IX and X showed dose-dependent increases at 30 min post-dose. Correspondingly, a dose-dependent TGA response was observed; 4F-PCC resulted in restoration to levels measured before anticoagulation with VKA. The degree of INR normalization appeared to be slightly more pronounced in the higher dosed 4F-PCC group. Factor II was almost normalized after 4F-PCC infusion and is known to be a main driver of the TGA response. Even though the other clotting factors, such as factor VII, remain in the range of approx. 50%, this does not represent a limitation for adequate activation of the coagulation system. Considering 4F-PCC characteristics and the mechanisms underlying either TGA or INR, the choice of TGA rather than INR appears to be more suitable to monitor appropriate restoration of the overall clotting potential after VKA reversal with 4F-PCC.

Multimodality Quantification of Thrombus Deposition in Extracorporeal Membrane Oxygenation (ECMO); Correlating Oxygenator Computed Tomography Imaging, Electron Microscopy and Histology to Clinical Outcomes

Introduction: Extracorporeal membrane oxygenation (ECMO) is essential for supporting cardiopulmonary function in critically ill patients, However, ECMO incurs thrombogenic risks due to activation of coagulation factors and blood cells by the biomaterial surfaces. This leads to complications such as frequent device replacement and systemic embolization despite the use of anticoagulation, suggesting additional mechanisms contribute to medical device-associated thrombosis. We propose that the geometry of the ECMO oxygenator significantly influences the structure and extent of clot formation and stability. To investigate this, we employed quantitative imaging and histologic techniques for a high-resolution, three-dimensional analysis of clot morphology in ECMO components, aiming to enhance our understanding of clot formation mechanisms, correlate these observations to clinical outcomes, and develop effective mitigation strategies. Methods: We developed a prospective study in which patients consented to the collection of blood samples, used ECMO components, and collection of relevant clinical variables. Computed tomography (CT) images were acquired using an Inveon microCT. H&amp;E stains, scanning electron microscopy (SEM), and CT images were processed through the Dragonfly software to accomplish a 3D visualization and analysis of clot composition. Clinical demographics and ECMO characteristics were recorded for each patient. Results: Digital photographs of used oxygenators are displayed in figure (A). Through CT scans, we quantified clot formation of distinct densities across the layers of the ECMO oxygenator (D). The results were able to quantify intraoxygenator thrombosis with high fidelity (27.65%, 14.56%, and 26.35% of the available membrane area was thrombosed across three representative oxygenators). Using a frontal CT scan to investigate clot formation identified five layers of varying structures across the intended path of blood flow (B). Clot formation was observed in layer 4 and layer 5, in which thrombosis occluded up to 12.2% of the layer on average. The overall ranking of clot formation under hemodynamic performance changes for all five layers was as follows: layer 5 &amp;gt; layer 4 &amp;gt; layer 1 = layer 2 &amp;gt;&amp;gt; layer 3. The use of anticoagulation at the time of ECMO decannulation significantly reduced the content of clot formation (P&amp;lt;0.0001). We then correlated digital biomarkers from imaging with thrombus composition. Detailed histological examination (HE) and SEM was undertaken on dismantled oxygenators (B &amp; C). We focused on thrombi at the interfaces and within the hollow fibers of the oxygenator. SEM and HE staining illustrated increased thickness, length, and density of fibrin structures in the thrombi from layer 5 to layer 4, whereas the numbers of platelets and cells decreased. Overall, layer 5 exhibited the most diverse types of thrombi, including blood cell-rich, platelet-rich, and fibrin-rich clots. We also observed aligned clots and significant clot formation in the hollow fiber area of layer 4, reflecting the geometry of the specific layer. Discussion: This pilot study examined the potential for imaging-based modalities to evaluate device associated thrombosis ex vivo, correlating these imaging findings to direct observations of thrombus composition and location. This methodology provides a platform to investigate ECMO device failure, identifying the key locations within select oxygenators where local device modification may be of most benefit. Future research will prioritize designing membrane oxygenator properties to minimize thrombus deposition, and will allow us to incorporate the use of serial imaging endpoints in future clinical trials evaluating medical device-associated thrombosis.