Coagulation Potential Research Articles

The in vitro cross-reactivity and blood coagulation potential of recombinant porcine factor VIII in Japanese patients with acquired hemophilia A.

Recombinant porcine factor VIII (rpFVIII) is a hemostatic agent for acquired hemophilia A (AHA). Cross-reaction of auto-antibodies against rpFVIII has been reported, although no data are available in Japanese patients. This study investigated the cross-reactivity and coagulation potential of rpFVIII in plasma samples from Japanese patients with AHA. Cross-reactivity was calculated as the ratio of anti-porcine FVIII inhibitor titer (pFVIII-INH) to human FVIII inhibitor titer. Comprehensive coagulation potential was assessed by clot waveform analysis (CWA) and thrombin generation assay (TGA) in samples spiked with rpFVIII (equivalent to 200 U/kg). Nine of 16 plasma samples (56.3%) had positive pFVIII-INH, with a median cross-reactivity of 1.2%. FVIII activity (FVIII:C) was restored to > 100% in all samples upon spiking with rpFVIII, but was weakly correlated with pFVIII-INH. CWA parameters and most TGA parameters were restored to normal upon spiking with rpFVIII; correlation of these parameters with FVIII:C was similar to that observed in controls. Overall, cross-reactivity to rpFVIII in Japanese patients was similar to that reported in Caucasian patients. Our results suggest that an initial clinical dose of 200 U/kg rpFVIII could restore coagulation potential to normal, and that FVIII:C monitoring after rpFVIII administration may be more informative than pFVIII-INH before administration.

Factor X consumption attenuates the coagulation effect of emicizumab: a case of severe hemophilia A treated with emicizumab and factor VIII-bypassing agents.

In patients with hemophilia A with inhibitor (PwHA-I), emicizumab drastically reduces bleeding events. However, few studies have investigated the behavior and effects of factor X (FX) in patients who require intensive treatment with factor VIII-bypassing agents (BPA) and emicizumab. A 59-year-old man with HA-I receiving emicizumab prophylaxis was admitted to our hospital because of acute gangrenous cholecystitis. He received percutaneous transhepatic gallbladder drainage and laparoscopic cholecystectomy along with repeated administration of recombinant activated factor VII (rFVIIa). On day 10, a large hematoma developed around the residual gallbladder. Rotational thromboelastometry (ROTEM) suggested poor effect of rFVIIa and reduced activity of emicizumab. Considering that this could be due to consumption of FX, plasma-derived FVIIa/FX agent (pdFVIIa/X) was administered, and ROTEM parameters recovered considerably. The patient was discharged on day 19 uneventfully. Plasma assays revealed that FX antigen level (FX:Ag) was 107.5% at baseline but then decreased. Administration of pdFVIIa/FX restored FX:Ag (pre/post 47.2%/125.5%). ROTEM and thrombin generation assay with in vitro addition of anti-emicizumab antibody suggested that low FX:Ag was responsible for attenuating the effect of emicizumab, and pdFVIIa/FX administration restored coagulation potentials. In PwHA-I receiving intensive treatment with rFVIIa under emicizumab prophylaxis, FX consumption might attenuate the effect of emicizumab.

Saliva of persons with hemophilia A triggers coagulation via extrinsic tenase complexes

AbstractHuman saliva contains extracellular vesicles (EVs). These EVs expose extrinsic tenase complexes of tissue factor (TF) and activated factor VII (FVIIa), and trigger blood coagulation. Here, we show that EVs exposing extrinsic tenase complexes are also present in saliva of persons with severe hemophilia A, that is, persons with FVIII deficiency. Addition of these salivary EVs to autologous FVIII-deficient blood results in FXa generation, thereby compensating for the lack of FXa generation via intrinsic tenase (FVIIIa/FIXa) complexes. Consistently, in our retrospective analysis of persons with severe hemophilia A who do not receive prophylactic FVIII substitution, oropharyngeal mucosal bleedings are infrequent and self-limited. Conversely, in saliva of persons with severe FVII deficiency, in whom oropharyngeal bleedings are prevalent, functional extrinsic tenase complexes are absent, because EVs lack FVII. Saliva of persons with severe FVII deficiency is unable to restore blood coagulation, which is because of the absence of FVII in both their saliva and blood. Picomolar levels of recombinant FVIIa can restore the coagulant potential of saliva of persons with FVII deficiency. Taken together, our findings may explain the paucity of oropharyngeal bleedings in persons with hemophilia A as well as the occurrence of such bleedings in persons with severe FVII deficiency.

The Effect of Increasing Factor X Levels on Emicizumab-Driven Coagulation Potential.

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Changes in coagulation potential over time after administration of recombinant activated factor VII in an emicizumab-treated hemophilia A patient with inhibitors.

We describe a 67-year-old patient with hemophilia A and inhibitors (PwHA-I) receiving emicizumab prophylaxis who underwent surgical treatment for pseudoaneurysm. He was treated with a bolus infusion of recombinant factor VIIa (rFVIIa; 79μg/kg) immediately before surgery, and a second dose of rFVIIa after an initial treatment on day 1. A third rFVIIa bolus was infused 17h after the second dose on day 2, and the treatment was continued every 24h on day 3 and day 4. Treatment with rFVIIa was discontinued on day 4. No perioperative bleeding or thrombotic events were observed. Coagulation potentials at 8h after rFVIIa administration determined by clot waveform analysis (CWA) and thrombin generation assay (TGA) were within near-normal ranges, and results at 17h after rFVIIa administration showed coagulation function comparable to that in the patient without rFVIIa. Our experimental data suggest that the coagulation potential in FVIII-deficient plasma spiked with both 0.28µg/mL (11.2μg/kg) rFVIIa and emicizumab was equivalent to or greater than that spiked with 2.2µg/mL (90μg/kg) rFVIIa alone. Thus, administration of rFVIIa every 8h may be feasible for managing perioperative treatment in emicizumab-treated PwHA-I.

Potential of natural coagulants for bioremediation of persistent organic pollutants in wastewater in sub-Saharan Africa: A review

Sub-Saharan Africa (SSA) is a significant user of pesticides, relying on agriculture for economic development. Pesticides and agrochemicals contribute to the presence of Persistent Organic Pollutants (POPs) in the environment. This review addresses knowledge gaps in monitoring and quantification of POPs, the application of natural coagulants for bioremediation, and associated environmental and health risks in SSA. Findings reveal inconsistencies in monitoring methods and analytes, hindering the identification of temporal trends. Legacy POPs show decreasing concentrations in soil/sediment and aquatic organisms, while some POPs increase in water, fish, fruits, and vegetables. Some river systems exceed acceptable ranges for PCBs according to USEPA standards. PFASs, particularly PFOA and PFOS, are prevalent. Natural coagulants, like Moringa oleifera and chitosan, are gaining popularity for water treatment due to their environmental sustainability and effectiveness in POP remediation. Trivalent cations in natural coagulants show promise for POP bioremediation. However, challenges remain in scaling up natural coagulant applications for commercial water treatment. This review highlights the need for standardized monitoring procedures and emphasizes the potential of natural coagulants in POP remediation efforts.

Postmodification with Polycations Enhances Key Properties of Alginate-Based Multicomponent Microcapsules.

Postmodification of alginate-based microspheres with polyelectrolytes (PEs) is commonly used in the cell encapsulation field to control microsphere stability and permeability. However, little is known about how different applied PEs shape the microsphere morphology and properties, particularly in vivo. Here, we addressed this question using model multicomponent alginate-based microcapsules postmodified with PEs of different charge and structure. We found that the postmodification can enhance or impair the mechanical resistance and biocompatibility of microcapsules implanted into a mouse model, with polycations surprisingly providing the best results. Confocal Raman microscopy and confocal laser scanning microscopy (CLSM) analyses revealed stable interpolyelectrolyte complex layers within the parent microcapsule, hindering the access of higher molar weight PEs into the microcapsule core. All microcapsules showed negative surface zeta potential, indicating that the postmodification PEs get hidden within the microcapsule membrane, which agrees with CLSM data. Human whole blood assay revealed complex behavior of microcapsules regarding their inflammatory and coagulation potential. Importantly, most of the postmodification PEs, including polycations, were found to be benign toward the encapsulated model cells.

The combination of Asp519Val/Glu665Val and Lys1813Ala mutations in FVIII markedly increases coagulation potential

AbstractA2 domain dissociation in activated factor VIII (FVIIIa) results in reduced activity. Previous studies demonstrated that some FVIII mutants (D519V/E665V and K1813A) with delayed A2 dissociation enhanced coagulation potential. We speculated, therefore, that FVIII encompassing a combination of these mutations might further enhance coagulant activity. The aim was to assess the D519V/E665V/K1813A-FVIII mutation as a gain of function. The FVIII mutants, D519V/E665V/K1813A, D519V/E665V, and K1813A were expressed in a baby hamster kidney cell system, and global coagulation potential of these mutants was compared with wild-type (WT) FVIII in vitro and in hemophilia A mice in vivo. Kinetic analyses indicated that the apparent Kd for FIXa on the tenase assembly with D519V/E665V and D519V/E665V/K1813A mutants were lower, and that the generated FXa for D519V/E665V/K1813A was significantly greater than WT-FVIII. WT-FVIII activity after thrombin activation increased by ∼12-fold within 5 minutes, and returned to initial levels within 30 minutes. In contrast, The FVIII-related activity of D519V/E665V/K1813A increased further with time after thrombin activation, and showed an ∼25-fold increase at 2 hours. The A2 dissociation rate of D519V/E665V/K1813A was ∼50-fold slower than the WT in a 1-stage clotting assay. Thrombin generation assays demonstrated that D519V/E665V/K1813A (0.125 nM) exhibited coagulation potential comparable with that of the WT (1 nM). In animal studies, rotational thromboelastometry and tail-clip assays showed that the coagulation potential of D519V/E665V/K1813A (0.25 μg/kg) was equal to that of the WT (2 μg/kg). FVIII-D519V/E665V/K1813A mutant could provide an approximately eightfold increase in hemostatic function of WT-FVIII because of increased FVIIIa stability and the association between FVIIIa and FIXa.

Characterization of extracellular vesicles from patients with severe aortic stenosis undergoing transcatheter aortic valve implantation and assessment of their coagulation potential

Abstract Funding Acknowledgements None. Background The pathogenesis of aortic stenosis (AS) includes processes of inflammation and calcification. Patients with aortic stenosis have increased risk of stroke. The amount of circulating extracellular vesicles (EVs) is elevated in patients with severe AS and decreases following valve intervention. The function of these EVs in the clinical setting of severe AS is not fully known. Aim With flow cytometry characterize EVs in patients with severe AS before and after Transcatheter Aortic Valve Implantation (TAVI). To investigate whether these EVs have a procoagulant effects by themselves or when incubated with human aortic endothelial cells (hAoECs), human cardiac microvascular endothelial cells (hCMVEC), human cardiac myocytes (hCM) and spheroids of hCMVEC and hCM. Methods 25 patients with severe AS were included in the study and blood samples collected before and 2 months after TAVI. The CytoFLEX flow cytometer (Beckman Coulter) was used for characterization of surface antigens on purified EVs. 2D-cultures of hAoECs, hCMVEC and hCM were incubated with EVs (100 mg/mL) for 6 hours (h) and spheroids of hCM and hCMVEC with EVs for 48h. An inhouse assay determining Tissue Factor (TF) activity by means of FXa generation in cell lysates were utilized. TF activity in purified EVs alone was determined using Tissue Factor Activity Assay kit (Human, colorimetric) from abcam. Results We found an increased level of TF positive EVs, phosphatidylserine (PS) positive EVs as well as double positive PS / TF expressing EVs in AS patients before TAVI compared to healthy controls and reduction of PS+ and TF+/PS+ expressing EVs after TAVI (Fig 1). When analyzing TF activity by means of FXa generation we found no procoagulant effect in the purified EVs alone nor when incubating EVs with hAoEC or hCM. In contrast, we found an increased TF activity in hCMVEC and spheroids of hCM and hCMVEC after incubation with EVs from AS patients compared to healthy EVs. Conclusion Patients with AS have increased amount of EVs expressing typically procoagulant surface antigens. The EVs by themselves have no procoagulant activity. However, upon interaction with hCMVEC and spheroids, consisting of hCMVEC and hCM, EVs appear to induce procoagulant activity in the recipient cells thus suggesting a possible link to thromboembolic events in coronary arteries. Additional studies are warranted to elaborate the mechanism and function of these TF, PS and TF / PS positive EVs.

Environmentally Friendly Natural Coagulants in the Coagulation Process in the Rubber Industry

This research evaluates the use of natural coagulants, such as soursop and Aegle marmelos (Maja), in the latex coagulation process of the GT 1 clone type, compared with chemical coagulants such as formic acid and acetic acid, to gain an understanding of the characteristics of the rubber produced. Three types of crumb rubber (SIR 3 CV, SIR 3L, and SIR 3 WF) are produced from latex, while SIR 5, SIR 10, and SIR 20 are produced from treated latex coagulum. Rubber quality criteria are explained in the Indonesian Rubber Standard (SIR 3L/3WF) SNI 06-1903-2011. The use of natural coagulants, especially soursop, and Maja, in the coagulation of GT 1 clone latex shows an influence on coagulation time, Dry Rubber Content (DRC), initial plasticity (Po), Plasticity Retention Index (PRI), ash content, dirt content, and substance content evaporate. The results showed that natural coagulants had slower coagulation times, higher DRC values ​​(especially in maja), and better PRI values ​​compared to chemical coagulants. Despite having higher ash content, dirt content, and volatile matter content, all types of coagulants meet rubber quality standards. This research provides in-depth insight into the potential and advantages of natural coagulants, especially soursop, and maja, in the environmentally friendly rubber industry. In addition, analysis of rubber characteristics, such as plasticity, resistance to heating, and content of certain components, provides a comprehensive understanding of the impact of the use of natural coagulants on rubber quality.

Clinical significance for assessing adaptive hemostasis changes during multiple pregnancy after in vitro fertilization

Aim: to assess adaptive hemostasis changes in multiple dichorionic pregnancy after in vitro fertilization (IVF). Materials and Methods. A prospective observational randomized controlled trial was conducted by examining 58 and 46 pregnant women with multiple dichorionic diamniotic twins resulting from applying assisted reproductive technologies (ART) and spontaneous delivery (comparison group), respectively. Hemostasis parameters were studied as follows: activated partial thromboplastin time (APTT), prothrombin time (PT), thrombin time (TT), fibrinogen, antithrombin, protein C, protein S, functions of protein С (РrоС Global test), D-dimer, platelet aggregation with adenosine-5-diphosphate (ADP), ristocetin, and collagen. Results. A high coagulation potential was revealed, more prominent after using ART (p < 0.05). Fibrinogen level gradually increased while gestation age increased, whereas APTT, PT and TT level decreased. In the group with natural conception, fibrinogen increased by 22 % in the second trimester, reaching 4.5 g/L (95 % CI = 4,2–4,8) and by 6 % in the third trimester, reaching 4.8 g/L (95 % CI = 4,3–5,4), whereas in the IVF group – by 26 %, reaching 5.3 g/L (95 % CI = 4,7–5,6) and by 21 %, reaching (6.5 g/L; 95 % CI = 5,2–6,8) in relevant trimester of pregnancy, respectively. Antithrombin level was lower in IVF patients – 76.8 % (95 % CI = 72.6 – 81.0) in the second trimester, reaching 70.6 % (95 % CI = 64.8–76.4) in the third trimester (p < 0.001). Protein C level did not differ significantly between groups and was low within the reference range. The aggregatogram demonstrated a high platelet hemostatic potential in IVF patients (p < 0.05) as early as in the first trimester: ADP-induced aggregation – 68.3 % (95 % CI = 62.9–73.7), ristocetin-induced aggregation – 53.1 % (95 % = CI 48.7–58.5), collagen-induced aggregation – 58.4 % (95 % CI = 52.1–64.7). In the third trimester, both platelet aggregation and functional activity (ADP-induced aggregation – 64.5 % [95 % CI = 59.3–69.7], ristocetin-induced aggregation – 68.4 % [95 % CI = 63.2–73.6], collagen-induced aggregation – 50.7 % [95 % CI = 44.3–57.1]; p < 0.05) and D-dimer level persistently increased, also more prominently in the IVF group (1.60 ± 0.46 ng/ml; p < 0.05). Conclusion. Gestational adaptation in induced multiple pregnancies is at high risk of breach in compensatory mechanisms and requires monitoring for timely detection of decompensation signs and their correction to prolong pregnancy till optimal delivery time frame.

Additional Factor X Enhances Emicizumab-Driven Coagulation Function in Patients with Hemophilia A and Hemophilia A Mice.

Bypassing agents are used for breakthrough bleedings in patients with hemophilia A with inhibitor (PwHAwI) receiving emicizumab prophylaxis. Previous study demonstrated a weak binding affinity between emicizumab and factor (F)X (K d; 1.85 μM), and that this value was much greater than the plasma FX concentration (∼130 nM). We speculated that increased FX levels could enhance coagulation potential in emicizumab-treated patients with hemophilia A (PwHA). To investigate the relationship between FX concentrations and emicizumab-driven coagulation. Plasma FX (up to 1,040 nM) and emicizumab (50 µg/mL) were added to FVIII-deficient plasmas, and plasma-derived FX (520 nM) or recombinant (r)FVIIa (2.2 µg/mL) was added to plasmas from three emicizumab-treated PwHAwI. The adjusted maximum coagulation velocity (Ad|min1|) by clot waveform analysis and peak thrombin (PeakTh) by thrombin generation assay in them were evaluated. Emicizumab (3.0 mg/kg), human (h)FIX (100 IU/kg), and various doses of hFX (100-500 IU/kg) were intravenously administered to HA mice. Clotting time/clot formation time (CT/CFT) were assessed using rotational thromboelastometry, and blood loss was estimated by a tail-clip assay. The addition of FX to FVIII-deficient plasma with emicizumab increased Ad|min1| and PeakTh. The coagulation parameters in emicizumab-treated PwHAwI spiked with additional FX remained within the normal range as well as the additional rFVIIa. In animal models, hFX injection shortened the CT and CT + CFT. The shorter CT and CT + CFT, and the lower blood loss were evident after 200 or 500 IU/kg hFX administration, and those indices were comparable to those in wild-type mice. Supplementation with FX may improve emicizumab-driven hemostasis in PwHA.

Longitudinal assessment of coagulation potential before, during, and following an in vitro fertilization cycle

IntroductionThe association between estrogen and hypercoagulability is well-established but little is known about coagulation dynamics during IVF. Our goal was to measure coagulation potential prior to, during, and following an IVF cycle and to investigate differences by conception outcome. Materials and methodsPatients undergoing IVF with fresh embryo transfer at a single academic center using oral contraceptive pills for cycle batching underwent evaluation of thrombin generation using the calibrated automated thrombogram at multiple points during the IVF cycle. Multiple thrombin generation parameters were compared across timepoints and by IVF cycle outcome using ANOVA repeated measures analysis. ResultsOf the 17 patients included, 11 conceived. There was a significant increase in peak and total thrombin generation in the entire cohort between the pre-treatment natural follicular phase and following a short course of oral contraceptive pills used for cycle batching. Further increase in these parameters was seen at the time of oocyte retrieval. In the pre-treatment natural follicular phase, patients who conceived had lower peak thrombin generation. There were changes throughout the cycle for factors II, V, VIII, X, XI, XII, antithrombin, and tissue factor pathway inhibitor. Only Factor XI was distinguishable by conception status; values were lower at all visits in patients who conceived. ConclusionIncreases in coagulation potential are seen in patients undergoing IVF following a short course of oral contraceptive pills for cycle batching and continue during controlled ovarian hyperstimulation. Those who conceived were seen to have lower peak thrombin generation in the pre-treatment natural follicular phase.

Optimization of Coagulation to Remove Turbidity from Surface Water Using Novel Nature-Based Plant Coagulant and Response Surface Methodology

Plant-based natural coagulants are considered potential alternatives to chemical coagulants. These are eco-friendly, non-toxic, and produce less sludge compared to chemical coagulants. This study aims to evaluate the coagulation potential of a novel plant-based coagulant Sorghum for canal water treatment. In addition, a coagulant aid, i.e., Aloe Vera, was also tested to examine any further increase in turbidity removal through a jar test apparatus. Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) were used to characterize the coagulants. The experiment was designed using response surface methodology (RSM). When used alone, Sorghum resulted in a maximum turbidity removal of 87.73% at pH 2 and a dose of 40 mg/L, while the combination of Sorghum and Aloe Vera resulted in a turbidity removal of 84.2% at pH 2.7, and the doses of Sorghum and Aloe Vera were 17.1 mg/L and 0.9% (v/v), respectively. Thus, the Sorghum dose was significantly reduced when Aloe Vera was used in combination. At a pH of 7, Sorghum achieved 54% turbidity removal at a dose of 55.7 mg/L. Analyses of variance revealed that pH plays a more vital role in the removal of turbidity than the coagulant dose. FTIR and SEM analyses revealed that adsorption is the dominant coagulation mechanism for plant-based coagulants. The Sorghum powder exhibited carboxylic, amine, and carbonyl groups that functioned as active adsorption sites for suspended solids. In a similar vein, the coagulant aid Aloe Vera gel facilitated the adsorption process by fostering intermolecular hydrogen bonding between suspended particles and amine groups present within the gel.

The effects of emicizumab on in vitro coagulation and fibrinolysis parameters in patients with disseminated intravascular coagulation with and without addition of anti-FVIII antibody.

Emicizumab (Emi) is used as haemostatic prophylaxis for patients with haemophilia A (PwHA). Disseminated intravascular coagulation (DIC) is a condition characterized by persistent systemic activation of coagulation, but there is yet no information on coagulation and fibrinolysis potentials in Emi-treated PwHA with DIC. To examine the effect of Emi on coagulation and fibrinolysis potentials in HA-model DIC plasmas. Plasma from a patient with sepsis-DIC (seven patients) was treated with anti-factor (F)VIII monoclonal antibody (HA-model DIC plasma) and incubated with Emi (50µg/mL). The plasma was then assessed using clot-fibrinolysis waveform analysis (CFWA). Coagulation and fibrinolysis parameters were expressed as ratios relative to normal plasma (|min1|-ratio and |FL-min1|-ratio, respectively). In case 1, coagulant potential was slightly high and fibrinolytic potential was extremely low, presenting a coagulant-dominant state (|min1|-ratio/|FL-min1|-ratio: 1.1/.38). In cases 2-5, fibrinolytic potential was not suppressed, but there were marked hypercoagulant potentials, indicating relative coagulant-dominant states. In case 6, coagulant and fibrinolytic potentials were increased but well balanced (|min1|-ratio/|FL-min1|-ratio: 1.38/1.28). In case 7, both potentials were severely deteriorated in not only CFWA but also the thrombin/plasmin generation assay. The addition of Emi into the HA-model DIC plasmas increased |min1|-ratio values in all cases, but the coagulant potentials did not exceed the initial ones (DIC plasma before treatment with anti-FVIII antibody). The presence of Emi in the HA-model DIC plasma improved coagulation potentials, but did not increase coagulation potentials beyond those of DIC plasma in non-HA states.

Reduced plasma factor X is associated with a lack of response to recombinant activated factor VII in patients with hemophilia A and inhibitor, but does not impair emicizumab-driven hemostasis in vitro

BackgroundThe hemostatic effect of recombinant (r) factor (F)VIIa after repetitive intermittent administration may be attenuated in patients with hemophilia A (PwHA) with inhibitors (PwHAwI) creating a clinically unresponsive status, although mechanism(s) remain to be clarified. In patients receiving prophylaxis treatment with emicizumab, concomitant rFVIIa is sometimes utilized in multiple doses for surgical procedures or breakthrough bleeding. Aim and methodsWe identified ‘unresponsiveness’ to rFVIIa, based on global coagulation function monitored using rotational thromboelastometry (ROTEM) in 11 PwHAwI and 5 patients with acquired HA, and investigated possible mechanisms focusing on the association between plasma FX levels and rFVIIa-mediated interactions. ResultsOur data demonstrated that FX antigen levels were lower in the rFVIIa-unresponsive group than in the rFVIIa-responsive group (0.46 ± 0.14 IU/mL vs. 0.87 ± 0.15 IU/mL, p < 0.01). This relationship was further examined by thrombin generation assays using a FX-deficient PwHAwI plasma model. The addition of FX with rFVIIa was associated with increased peak thrombin (PeakTh) generation. At low levels of FX (<0.5 IU/mL), rFVIIa failed to increase PeakTh to the normal range, consistent with clinical rFVIIa-unresponsiveness. In the presence of emicizumab (50 μg/mL), PeakTh was increased maximally to 80 % of normal, even at low levels of FX (0.28 IU/mL). ConclusionsUnresponsiveness to rFVIIa was associated with reduced levels of FX in PwHAwI. Emicizumab exhibited in vitro coagulation potential in the presence of FX at concentrations that appeared to limit the clinical response to rFVIIa therapy.

Global Hemostatic Methods to Tailor Treatment With Bypassing Agents in Hemophilia A With Inhibitors- A Single-Center, Pilot Study.

For patients with hemophilia A and high-titer inhibitors treated with bypassing agents there are no reliable methods to assess treatment effect. We investigated the utility of global hemostatic methods in assessing treatment with bypassing agents (rFVIIa or activated prothrombin complex [aPCC]). All patients with hemophilia A and inhibitors followed at the Coagulation Unit or the Pediatric Coagulation Unit at Karolinska University Hospital aged 6 years and above were eligible for this noninterventional study. Baseline plasma samples were spiked with bypassing agents in increasing concentrations (aPCC 50 U/kg, 100 U/kg, 150 U/kg, and rFVIIa 90 μg/kg and 270 μg/kg) in vitro. For patients treated with factor concentrates or bypassing agents follow-up samples were collected (in vivo tests). The samples were analyzed using overall hemostatic potential (OHP), and calibrated automated thrombogram, Calibrated Automated Thrombogram (CAT). Nine patients with hemophilia A with inhibitors were included. Spiking with rFVIIa normalized the coagulation potential in 6/8 samples, in 3 only with high dose. Only one sample did not improve adequately after spiking with aPCC. The improvement in hemostasis was reliably shown by both CAT and OHP. The baseline potential was, however, more often measurable by OHP compared to CAT. Factor concentrate had been administered to 5 patients normalizing the hemostatic potential in vivo in 2 (without spiking). The hemostatic improvement induced by spiking with rFVIIa or aPCC is shown by OHP and CAT, but the results have to be evaluated in larger cohorts.

Acute effects of high intensity interval training versus moderate intensity continuous training on haemostasis in patients with coronary artery disease

Exercise training is associated with an acute net increase in coagulation, which may increase the risk of atherothrombosis in coronary artery disease (CAD) patients. We sought to compare the acute haemostatic effects of a bout of moderate-intensity continuous (MICT) and high-intensity interval training (HIIT) in patients with CAD. Patients after a recent myocardial infarction were randomized into a HIIT or MICT session of exercise training on a stationary bike. Blood was sampled at baseline, after the exercise bout and after a one-hour resting period. We measured overall haemostatic potential (OHP), overall coagulation potential (OCP), fibrinogen, D-dimer and von Willebrand factor (vWF) and calculated overall fibrinolytic potential (OFP). Linear mixed models for repeated measures were constructed to assess the treatment effect. A total of 117 patients were included. OCP, OHP, fibrinogen, D-dimer and vWF significantly increased after exercise and returned to baseline after a one-hour rest, OFP decreased after exercise and returned to baseline levels after a one-hour rest. Linear mixed models showed a significant difference between HIIT and MICT in fibrinogen (p 0.043) and D-dimer (p 0.042). Our study has shown that an exercise bout is associated with a transient procoagulant state in patients with CAD, with similar exercise-induced haemostatic changes for HIIT and MICT.

Exercise and hypoxia-induced hypercoagulability is counterbalanced in women in part by decreased platelet reactivity

Hypoxia plays an important role in several pathologies, e.g. chronic obstructive pulmonary disease and obstructive sleep apnea syndrome, and is linked to an increased thrombosis risk. Furthermore, oxygen deprivation is associated with hypercoagulability.In this study, we investigated the effect of gender and exercise on the coagulation potential under hypoxic conditions at high altitude by assessing thrombin generation (TG) and platelet activation. Hereto, ten healthy volunteers were included (50 % male, median age of 27.5 years). The measurements were conducted first at sea level and then twice at high altitude (3883 m), first after a passive ascent by cable car and second after an active ascent by a mountain hike.As expected, both the passive and active ascent resulted in a decreased oxygen saturation and an increased heart rate at high altitude. Acute mountain sickness symptoms were observed independently of the ascent method. After the active ascent, platelet, white blood cell and granulocyte count were increased, and lymphocytes were decreased, without a gender-related difference. FVIII and von Willebrand factor were significantly increased after the active ascent for both men and women. Platelet activation was reduced and delayed under hypobaric conditions, especially in women. TG analysis showed a prothrombotic trend at high altitude, especially after the active ascent. Women had a hypercoagulable phenotype, compared to men at all 3 timepoints, indicated by a higher peak height and endogenous thrombin potential (ETP), and shorter lag time and time-to-peak. In addition, ETP and peak inhibition by thrombomodulin was lower in women after the active ascent, compared to men. Interestingly, data normalisation for subject baseline values indicated an opposing effect of altitude-induced hypoxia on α2-macroglobulin levels and TG lag time between men and women, decreasing in men and increasing in women.We conclude that hypoxia increases TG, as well as FVIII and VWF levels in combination with exercise. In contrast, platelets lose their responsiveness at high altitude, which is most pronounced after heavy exercise. Women had a more pronounced prothrombotic phenotype compared to men, which we theorize is counterbalanced under hypobaric conditions by decreased platelet activation.

Improvements in markers of inflammation and coagulation potential following a 5-day high-fat diet rich in cottonseed oil vs. Olive oil in healthy males

Low-grade inflammation is believed to be a risk factor for chronic diseases and is nutritionally responsive. Cottonseed oil (CSO), which is rich in n-6 polyunsaturated fats, has been shown to lower cholesterol and other chronic disease risk factors. The purpose of this secondary analysis was to determine the comparative responses of markers of inflammation and coagulation potential of healthy adult males consuming diets rich in CSO vs. olive oil (OO). MethodsFifteen normal-weight males, ages 21.7 ± 2.58y, completed a randomized crossover trial. Each intervention consisted of a 3-day lead-in diet and a 5-day outpatient, controlled feeding intervention (CSO or OO). There was a 2 to 4-week washout period between interventions. The 5-day intervention diets were 35 % carbohydrate, 15 % protein, and 50 % fat, enriched with either CSO or OO (44 % of total energy from oil). At pre- and post- diet intervention visits, a fasting blood draw was collected for analysis of markers of inflammation (Tumor Necrosis Factor Alpha (TNF-α), Interleukin-6 (IL-6), C-Reactive Protein (CRP)) and coagulation potential (Tissue Factor (TF), Plasminogen Activator Inhibitor-1 (PAI-1)). ResultsThe CSO-enriched diets reduced TNF-α (CSO: −0.12 ± 0.02 pg/ml, OO: −0.01 ± 0.05 pg/ml; p < 0.01) and TF (CSO: −0.59 ± 0.68 pg/ml, OO: 1.13 ± 0.83 pg/ml; p = 0.02) compared to OO diets. There were no differences in IL-6, CRP, or PAI-1 between diets. ConclusionA 5-day, CSO-enriched diet may be sufficient to reduce inflammation and coagulation potential compared to OO-enriched diets in a healthy male population which could have implications in chronic disease prevention.