Thrombin generation and rotational thromboelastometry in the healthy adult population

2015 ◽  
Vol 35 (02) ◽  
pp. 181-186 ◽  
Author(s):  
T. Schneider ◽  
T. Siegemund ◽  
R. Siegemund ◽  
S. Petros
Keyword(s):  
Tissue Factor ◽  
Linear Correlation ◽  
Thrombin Generation ◽  
Alpha Angle ◽  
Lag Time ◽  
Published Data ◽  
Peak Time ◽  
Clotting Time ◽  
Rotational Thromboelastometry ◽  
Maximum Clot Firmness

SummaryPublished data on thrombin generation variables and their correlation with thrombo - elastometry in the healthy population are scarce. This study aimed at assessing thrombin generation in adults and its correlation to classical rotational thromboelastometry (ROTEM).Thrombin generation was measured in platelet-poor plasma from healthy volunteers using the calibrated automated thrombogram (CAT) with 1 and 5 pmol/l tissue factor final concentration. Lag time, thrombin peak, time to thrombin peak and endogenous thrombin potential (ETP) were analyzed. ROTEM was performed without activator (NATEM) and data for clotting time, alpha angle, clot formation time and maximum clot firmness were correlated with those of thrombin generation.Altogether 132 persons (72 men, 60 women; median age: 48.0 years) were included. There was a positive non-linear correlation for age versus lag time (p < 0.001) and time to peak (p = 0.001), and almost linear correlation for age versus thrombin peak (p = 0.024) and ETP (p = 0.001), although with a moderate regression slope. Regarding ROTEM, there was a positive correlation between age and maximum clot firmness and alpha angle (p = 0.001), but a negative correlation between age and clotting time (p = 0.039). Comparing both assays, thrombin peak and ETP measured with a final tissue factor concentration of 5 pmol/l correlated significantly with alpha angle and maximum clot firmness.The age-related changes in CAT and ROTEM variables among adults are not linear. There is a significant correlation, although with a moderate slope, between data from CAT measured with 5 pmol/l tissue factor and ROTEM.

Fibrinogen: A Procoagulant and An Anticoagulant

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 384-384 ◽  
Author(s):  
Catherine J Rea ◽  
Benny Sorensen ◽  
Jørgen Ingerslev ◽  
Peter Laursen
Keyword(s):  
Tissue Factor ◽  
Whole Blood ◽  
Thrombin Generation ◽  
Plasma Concentrations ◽  
Lag Time ◽  
Clot Formation ◽  
Fibrinogen Concentration ◽  
Clotting Time ◽  
Dose Dependent ◽  
Clot Stability

Abstract Abstract 384 Fibrinogen: A Procoagulant and an Anticoagulant Introduction: Bleeding occurs secondary to acquired fibrinogen deficiency but the effect of high fibrinogen is more controversial. Correlation between raised fibrinogen levels and venous or arterial thrombosis has been recorded. However, fibrinogen increases as an acute phase response and may be an innocent biomarker, detected at elevated levels in individuals with concomitant disease. Recent animal studies provide evidence that high fibrinogen does not trigger thrombosis per se, but enhances thrombotic occlusion of vessels following tissue injury. Aims: This study aims to investigate the effect of elevated levels of fibrinogen on thrombin generation and clot resistance to accelerated fibrinolysis. We hypothesised that fibrinogen promotes clot stability following a high tissue factor stimulus (TF), but will act as an anticoagulant following low TF stimulus. Method: Normal human plasma was spiked with fibrinogen to achieve final plasma concentrations of 2.7, 3.2, 3.7, 4.7, 5.7, 6.7, 8 and 11.7g/l. Coagulation was initiated with TF at variable dilutions (1:20000, 1: 500) plus calcium. To assess clot stability the same assay was performed with simultaneous addition of tissue plasminogen activator (t-Pa 0.75nmolar). Clot formation and lysis was recorded via light absorbance (FLUOstar Omega). Clot stability was also measured by whole blood thromboelastometry; citrate and CTI stabilized whole blood was drawn from a healthy individual and spiked with fibrinogen (calculated plasma concentrations: 3.2, 4, 3.9, 5.5, 9.9, 16 g/l). Coagulation was triggered with TF (1: 50000 or 1:500), calcium and of t-Pa (2nmolar). The area under elasticity curve (AUEC) at 90mins was the primary endpoint. Thrombin generation in plasma was performed in plasma following addition of fibrinogen using fluorogenic substrate and calcium (FluCä, Thrombinoscope BV, The Netherlands). Results:Plasma clot formation assay: Dose dependent shortening of clot time and time to peak turbidity were seen with increasing fibrinogen following a high TF stimulus (TF 1:500) (figure 1- panel A). Conversely, following a low TF stimulus increasing fibrinogen caused a lengthening of the clotting time. Plasma and whole blood lysis assays: With high TF stimulus, fibrinogen produced a dose-dependent increase in clot stability measures (AUC/AUEC) in both plasma and whole blood assays (figure 1-panel B). Following a low TF stimulus increases in the fibrinogen concentration resulted in suppressed clot stability. Thrombin generation: A decrease in total thrombin generation was seen with increasing fibrinogen (Figure 2) at both high and low TF levels. With high TF there was no alteration in lag-time, but with low TF stimulus the lag-time progressively lengthened as fibrinogen concentration increased. Discussion: Fibrinogen acts as a pro-coagulant by promoting clot formation and supports clot stability following a high TF stimulus. However, following a low TF stimulus elevated fibrinogen becomes an anticoagulant as demonstrated by prolonging clotting time and decreases clot stability in both plasma and whole blood. In conclusion, our data suggest that elevated fibrinogen per se is not thrombogenic. However, following a significant trauma resulting in a high tissue factor stimulus and high thrombin generation, fibrinogen acts predominantly as a pro-coagulant enhancing clot formation and supporting clot stability. This may protect against bleeding or contribute to pathological thrombotic events. In contrast, following a minor trauma prompting a minimal tissue factor stimulus, fibrinogen predominantly acts as an anticoagulant and may protect against thrombosis. Disclosures: No relevant conflicts of interest to declare.

Analysis of Racial Disparity in Plasma of Healthy Volunteers Using Rotational Thromboelastometry Reveals Higher Prothrombotic Profile in African Americans

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 5972-5972 ◽  
Author(s):  
Maissaa Janbain ◽  
Walter J Liszewski ◽  
Cindy A Leissinger
Keyword(s):  
African Americans ◽  
Healthy Volunteers ◽  
Racial Differences ◽  
Whole Blood ◽  
Thrombin Generation ◽  
Alpha Angle ◽  
Formation Time ◽  
Rotational Thromboelastometry ◽  
Clot Formation Time ◽  
Maximum Clot Firmness

Racial differences in the incidence of arterial and venous thrombotic events are well established in literature, with a higher incidence noted in African Americans compared to Caucasians. Several studies have tried to explain this difference, by looking separately at chemical biomarkers, socioeconomic and clinical risk factors. Yet the exact reason behind this disparity remains unclear. At least one study of thrombin generation suggested that African ethnicity was associated with increased peak thrombin generation when compared to Caucasians. Rotational thromboelastometry is a visco-elastic methodology that offers a global assessment of hemostasis using either whole blood or plasma. We explored the racial differences in rotational thromboelastometry findings using plasma samples from healthy volunteers. We studied a cohort of 9 otherwise healthy adult volunteers with no history of cardiovascular nor thromboembolic events, 5 African Americans and 4 Caucasians. After informed consent, we collected citrated whole blood samples and processed them within 3 hours of phlebotomy. Platelet free plasma, obtained after centrifugation of whole blood for 20 minutes, was kept frozen at -70°C, and then thawed at 37°C for 5 minutes prior to testing. Samples were re-calcified with star-tem® reagent, and then the in-tem® reagent was added. The latter contains an optimized concentration of ellagic acid and partial thromboplastin phospholipid from rabbit brain. Thromboelastometry parameters including Clot Formation Time, Alpha Angle, and Maximum Clot Firmness were determined. We then compared the data between the two study populations using parametric unpaired Student’s t-test. Our results showed that the Clot Formation Time was higher in the plasma of Caucasians when compared to African Americans with a difference between means of 40.1 ± 4.4 seconds (p <.0001); the Alpha Angle was lower in Caucasians with a difference between means of 3.45 ± 0.3 degrees (p <.0001); and the Maximum Clot Firmness was lower in Caucasians with a difference between means of 9.75 ± 2 mm (p <.01). These findings demonstrated that the plasma of Caucasians took longer to reach the maximum firmness, and this maximum firmness was less than that reached in the plasma of African Americans. This reveals a significantly increased prothrombotic profile in the plasma of African Americans compared to Caucasians. Despite the limited number of participants, the striking observed differences in the thromboelastometry parameters suggest that global assays may offer benefit in assessing thrombotic risks in disparate patient populations, as they incorporate multiple components of the hemostatic system. Higher numbers of subjects and assessment of both whole blood and plasma are indicated. We are currently in the process of expanding our cohort to confirm these preliminary results. Disclosures No relevant conflicts of interest to declare.

Prevalence of Acute Traumatic Coagulopathy in Acutely Traumatized Dogs and Association with Clinical and Laboratory Parameters at Presentation

2021 ◽  
Author(s):  
Yaiza Herrero ◽  
Rahel Jud Schefer ◽  
Benjamin M. Muri ◽  
Nadja E. Sigrist
Keyword(s):  
Clotting Time ◽  
Acute Traumatic Coagulopathy ◽  
Rotational Thromboelastometry ◽  
Clot Strength ◽  
Laboratory Parameters ◽  
Coagulation Abnormalities ◽  
Trauma Triage ◽  
Clot Formation Time ◽  
Maximum Clot Firmness ◽  
Traumatic Coagulopathy

Abstract Objective The aim of this study was to determine the prevalence of acute traumatic coagulopathy (ATC) and identify associated clinical and laboratory parameters including rotational thromboelastometry. Study Design Dogs presenting within 6 hours after trauma were allocated to the ATC or non-ATC group based on thromboelastometry analysis (ex-tem S, in-tem S, fib-tem S). ATC was defined as ≥2 hypocoagulable parameters in 1 profile and ≥ 1 hypocoagulable parameter in an additional profile. Parameters used were ex-tem and in-tem clotting time (CT), clot formation time (CFT), maximum clot firmness (MCF), maximum lysis and fib-tem MCF. Clinical and laboratory parameters at presentation, animal trauma triage (ATT) score, transfusion requirement and outcome were compared. Logistic regression was used to identify independent factors associated with ATC. Results Eleven of 33 dogs presented with ATC and showed ex-tem CT and CFT prolongation and reduced MCF amplitude in all profiles (all p < 0.001). pH (p = 0.043) and potassium concentration (p = 0.022) were significantly lower and bleeding (p = 0.027) and plasma transfusions (p = 0.001) more common in dogs with ATC. Time after trauma (p = 0.040) and Animal Trauma Triage score (p = 0.038, including haematocrit as confounding factor) were associated with the presence of ATC. Conclusion Acute traumatic coagulopathy is more common in traumatized dogs than previously reported. Acute traumatic coagulopathy was associated with acidosis, Animal trauma triage score, time after trauma and higher transfusion needs. Coagulation abnormalities include ex-tem CT and CFT prolongations and decreased clot strength.

scholarly journals Thrombin generation in cardiovascular disease and mortality - results from the Gutenberg Health Study

Haematologica ◽  
2019 ◽  
Vol 105 (9) ◽  
pp. 2327-2334 ◽  
Author(s):  
Pauline C.S. van Paridon ◽  
Marina Panova-Noeva ◽  
Rene van Oerle ◽  
Andreas Schultz ◽  
Iris M. Hermanns ◽  
...  
Keyword(s):  
Risk Factors ◽  
Cardiovascular Risk ◽  
Cardiovascular Diseases ◽  
Cardiovascular Risk Factors ◽  
Tissue Factor ◽  
Thrombin Generation ◽  
Cox Regression ◽  
Total Mortality ◽  
Lag Time ◽  
Endogenous Thrombin Potential

Thrombin generation may be a potential tool to improve risk stratification for cardiovascular diseases. This study aims to explore the relation between thrombin generation and cardiovascular risk factors, cardiovascular diseases, and total mortality. For this study, N=5000 subjects from the population-based Gutenberg Health Study were analysed in a highly standardized setting. Thrombin generation was assessed by the Calibrated Automated Thrombogram method at 1 and 5 pM tissue factors trigger in platelet poor plasma. Lag time, endogenous thrombin potential, and peak height were derived from the thrombin generation curve. Sex-specific multivariable linear regression analysis adjusted for age, cardiovascular risk factors, cardiovascular diseases and therapy, was used to assess clinical determinants of thrombin generation. Cox regression models adjusted for age, sex, cardiovascular risk factors and vitamin K antagonists investigated the association between thrombin generation parameters and total mortality. Lag time was positively associated with obesity and dyslipidaemia for both sexes (p<0.0001). Obesity was also positively associated with endogenous thrombin potential in both sexes (p<0.0001) and peak height in males (1 pM tissue factor, p=0.0048) and females (p<0.0001). Cox regression models showed an increased mortality in individuals with lag time (1 pM tissue factor, hazard ratio=1.46, [95% CI: 1.07; 2.00], p=0.018) and endogenous thrombin potential (5 pM tissue factor, hazard ratio = 1.50, [1.06; 2.13], p=0.023) above the 95th percentile of the reference group, independent of the cardiovascular risk profile. This large-scale study demonstrates traditional cardiovascular risk factors, particularly obesity, as relevant determinants of thrombin generation. Lag time and endogenous thrombin potential were found as potentially relevant predictors of increased total mortality, which deserves further investigation.

scholarly journals Prospective Assessment of Biomarkers of Hypercoagulability in Oncological Patients and Healthcare Workers Following Vaccination Against Sars-Cov-2 with the mRNA Vaccine. the Roadmap-COVID-19-Vaccin Study

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 3207-3207
Author(s):  
Patrick Van Dreden ◽  
Joseph Gligorov ◽  
Evangelos Terpos ◽  
Mathieu Jamelot ◽  
Michele Sabbah ◽  
...  
Keyword(s):  
Endothelial Cell ◽  
Tissue Factor ◽  
Platelet Activation ◽  
Research Funding ◽  
Thrombin Generation ◽  
Cell Activation ◽  
Control Group ◽  
Clotting Time ◽  
Endothelial Cell Activation ◽  
Active Cancer

Abstract Background: COVID-19 has been associated with hypercoagulability, endothelial cell injury and frequent thrombotic complications resulting both from direct effects of the virus on the endothelium and from the 'cytokine storm' resulting from the host's immune response. Since the COVID-19 vaccines have been shown to effectively prevent symptomatic infection including hospital admissions and severe disease, the risk of COVID-19-related thrombosis should be expected to (almost) disappear in vaccinated individuals. However, some rare cases of venous thrombosis have been reported in individuals vaccinated with mRNA vaccines. Thus, there is a sharp contrast between the clinical or experimental data reported in the literature on COVID-19 and on the rare thrombotic events observed after the vaccination with these vaccines. This phenomenon raised some scepticism of even some fear about the safety of these vaccines which could compromise the adhesion of the citizens in the vaccination program. Aims: We conducted a prospective observational study, to explore the impact of vaccination with the BNT162b2 (Pfizer/BioNTech) on blood hypercoagulability and endothelial cell activation and to investigate if this is modified by the presence of active cancer. Methods: In total 229 subjects were prospectively included in the study from April to June 2021. Subjects were stratified in three predefined groups: 127 vaccinated patients with active cancer (VOnco group), 72 vaccinated health care workers (VHcw group) and 30 non vaccinated health individuals (Control group). Blood samples were obtained 2 days after the administration of the first dose of BNT162b2 vaccine and collected in Vacutainer® tubes (0.109 mol/L trisodium citrate). Platelet poor plasma (PPP) was prepared by double centrifugation at 2000 g for 20 minutes at room temperature and plasma aliquots were stored at -80°C until assayed. Samples of PPP were assessed for thrombin generation (TG) with PPP-Reagent® (Thrombogram-Thrombinoscope assay with PPP-Reagent®TF 5pM), E-selectin, D-dimers, (D-Di), Tissue Factor (TFa), procoagulant phospholipid-dependent clotting time (Procag-PPL) and von Willebrand factor (vWF), thrombomodulin (TM), tissue factor pathway inhibitor (TFPI), and platelet factor 4 (PF4). All assays were from Diagnostica Stago (France). The upper and lower normal limits (UNL and LNL) for each biomarker were calculated by the mean±2SD for the control group. Results: All vaccinated subjects showed significantly increased levels of PF4 (71% &gt;UNL, p&lt;0.001), D-Dimers (74% &gt;UNL, p&lt;0.01), vWF (60% &gt;UNL, p&lt;0.01), FVIII (62% &gt;UNL, p&lt;0.01) and shorter Procoag-PPL clotting time (96% &lt;LNL, p&lt;0.001), as compared to controls. Thrombin generation showed significantly higher Peak (60% &gt;UNL, p&lt;0.01), ETP (38% &gt;UNL, p&lt;0.01) and MRI (66% &gt;UNL, p&lt;0.01) but no differences in lag-time in vaccinated subjects as compared to the control group. Vaccinated subjects did not show any increase at the levels of TFa, TFPI, TM and E-selectin in comparison with the control group. The studied biomarkers were not significantly different between the VOnco and VHcw groups. Conclusion: The ROADMAP-COVID-19-Vaccine study shows that administration of the first dose of the BNT162b2 vaccine induced significant platelet activation documented by shorter Procoag-PPL associated with increased levels of PF4. Plasma hypercoagulability was less frequent in vaccinated individuals whereas there was no evidence of significant endothelial cells activation after vaccination. Interestingly, the presence of active cancer was not associated with an enhancement of platelet activation, hypercoagulability, or endothelial cell activation after the vaccination. Probably, the generated antibodies against the spike protein or lead to platelet activation in a FcyRIIa dependent manner that results in PF4 release. The implication of the mild inflammatory reaction triggered by the vaccination could be another possible pathway leading to platelet activation. Nevertheless, vaccination does not provoke endothelial activation even in patients with cancer. The findings of the ROADMAP-COVID-19-Vaccine study support the concept administration of mRNA based vaccines does not directly cause a systematic hypercoagulability. Disclosures Gligorov: Roche-Genentech: Research Funding; Novartis: Research Funding; Onxeo: Research Funding; Daichi: Research Funding; MSD: Research Funding; Eisai: Research Funding; Genomic Heatlh: Research Funding; Ipsen: Research Funding; Macrogenics: Research Funding; Pfizer: Research Funding. Terpos: Novartis: Honoraria; Janssen: Consultancy, Honoraria, Research Funding; Genesis: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; BMS: Honoraria; Amgen: Consultancy, Honoraria, Research Funding; Takeda: Consultancy, Honoraria, Research Funding; Sanofi: Consultancy, Honoraria, Research Funding; GSK: Honoraria, Research Funding. Dimopoulos: Amgen: Honoraria; BMS: Honoraria; Janssen: Honoraria; Beigene: Honoraria; Takeda: Honoraria.

In Vitro Effect of Danaparoid Sodium (Orgaran®) on Thrombin Generation after Minimal Tissue Factor Pathway Activation.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 4151-4151
Author(s):  
Ismail Elalamy ◽  
Anna D. Petropoulou ◽  
Mohamed Hatmi ◽  
Meyer M. Samama ◽  
Grigoris T. Gerotziafas
Keyword(s):  
Molecular Weight ◽  
Tissue Factor ◽  
Thrombin Generation ◽  
Lag Time ◽  
Dependent Manner ◽  
Pathway Activation ◽  
Coagulation Tests ◽  
Vitro Effect ◽  
Routine Coagulation

Abstract Introduction: Orgaran® (Org 10172) is a low molecular weight heparinoid which consists of natural sulphated glycosaminoglycans (heparan, dermatan, chondroitin sulphate). It has a mean molecular weight of approximately 6 kDa (4–10 kDa), an excellent bioavailability following subcutaneous administration and an anti-Xa/anti-IIa activity ratio superior to 22. It is the anticoagulant of choice in patients developping Heparin-Induced Thrombocytopenia (HIT), whereas its’ use is also proposed for surgical thromboprophylaxis. Orgaran® has no effect on routine coagulation tests (aPTT, PT, TT). Thrombin generation test(TG) is a global clotting assay proven to be sensitive to the anticoagulant effect of LMWHs and specific FXa inhibitors (i.e. fondaparinux and BAY-597939). In this in vitro study, we determined the tissue factor (TF)-induced TG inhibition potency of Orgaran® using the Thrombogram-Thrombinoscope® assay. Materials and Methods: TG was assessed after TF pathway activation in Platelet Rich Plasma (PRP) (1.5x105 platelets/μl) using diluted thromboplastin (Dade Innovin®, 1:1000 final dilution). The clotting process is provoked by a physiologically relevant TF concentration. Orgaran® was added to control plasma from 8 healthy volunteers at five different final concentrations (0.2, 0.4, 0.6, 0.8 and 1IU anti-Xa/ml). TG was initiated by adding the triggering solution containing CaCl2 and the fluorogenic substrate. The analyzed TG parameters are the lag time, the maximal concentration of thrombin (Cmax), the time to reach Cmax (Tmax), the TG velocity and the endogenous thrombin potential (ETP). Results: Orgaran® prolonged significantly the lag time and the Tmax at a concentration over 0.40 IU anti-Xa/ml (p<0.05). At the lowest studied concentration (0.20 IU anti-Xa/ml), lag time and Tmax were only prolonged by 12%, whereas their maximal prolongation (around 50%) was observed at 1IU anti-Xa/ml. Furthermore, Orgaran® inhibited ETP, Cmax and TG velocity in an almost linear dose dependent manner. A significant inhibition of ETP, Cmax and TG velocity was obtained at concentrations superior to 0.20 IU anti-Xa/ml. (p<0.05). At the highest studied concentration (1IU anti-Xa/ml) Orgaran® suppressed all TG parameters by about 80% (Table 1). Conclusion: Orgaran® exhibited a significant inhibitory activity of in vitro TG. At concentrations achieved in clinical practice (prophylactic or therapeutic dose), Orgaran® modified in vitro TG profile while it has no effect on routine coagulation tests. Thus, TG assay is a sensitive method for monitoring Orgaran® and this test requires a clinical prospective evaluation. Table 1. Determination of IC20 and IC50 anti-Xa inhibitory concentrations of Orgaran® on TG parameters Lag Time Tmax ETP Cmax Velocity IC: Inhibitory Concentration * or Concentration increasing 20% and 50% the lag time and the Tmax respectively IC 20 (IU/ml) 0.30 0.30 0.18 0.18 0.15 IC 50 (IU/ml) 0.83 >1 0.30 0.50 0.35 1IU anti-Xa/ml 53% 47% 68% 76% 84%

Eculizumab Therapy Results in Rapid and Sustained Decreases in Markers of Thrombin Generation and Inflammation in Patients with PNH

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 407-407 ◽  
Author(s):  
Ilene Ceil Weitz ◽  
Michael Ghods ◽  
Leanne Rochanda ◽  
Pedram Prazavi ◽  
Jeffrey Zwicker ◽  
...  
Keyword(s):  
Cell Membrane ◽  
Tissue Factor ◽  
Thrombin Generation ◽  
Treatment Protocol ◽  
Rank Test ◽  
Prior History ◽  
Published Data ◽  
Induction Phase ◽  
Membrane Injury ◽  
Increased Risk

Abstract Paroxysmal Nocturnal Hemoglobinuria (PNH) is a clonal disorder of the bone marrow resulting from an acquired mutation in the PIG-A gene. The mutation decreases production of the glycosylphosphatidylinositol membrane anchor for a variety of membrane proteins. Loss of cell membrane CD59 and CD55 results in enhanced complement-mediated cell membrane injury. PNH is associated with an increased risk of venous (VTE) and arterial thrombosis. Eculizumab, a monoclonal antibody to complement C5, has received FDA approval for the treatment of PNH. Recent published data demonstrates a 92% reduction in thrombotic events with the use of eculizumab. However, the mechanism for this reduction is unclear. We have enrolled eight PNH patients (pts) in an ongoing IRB-approved study on the effect of eculizumab treatment on markers of thrombin generation and inflammation. Patients were treated by the FDA-approved treatment protocol with blood samples obtained prior to treatment day 1 and prior to each dose on days 8, 15, 22, 29, 43 and 90. Patients receiving anticoagulants and corticosteroids were continued on their baseline medications. Plasma samples were assayed for D-dimers (D-D), thrombin-antithrombin complex (TAT), interleukin 6 (Il-6) by ELISA and tissue factor microparticles (TFMP) by impedance-based flow cytometry. Mean age of pts was 40.8 years (26–70); 6 male pts and 2 females. One patient had a prior history of VTE; 4 pts were receiving anticoagulants (1 full dose low molecular weight heparin (LMWH), 2 prophylactic LMWH, 1 warfarin) and 2 pts were receiving prednisone at the initiation of eculizumab. The effect of eculizumab on markers of hemostatic activation and inflammation was evaluated using Wilcoxon signed-rank test and multilevel models. Results: Pretreatment levels of D-D were significantly elevated in all but two of the patients who were receiving anticoagulants. Pretreatment Il-6 levels were significantly elevated in all but two patients taking prednisone. With eculizumab treatment, there was a statistically significant decrease in LDH (p=0.0001), D-D (p=0.0057), TAT (0.0138) and Il-6 (p=0.0362) during the 4 week induction phase of treatment (days 1–29). TAT levels significantly decreased by day 8 (p=0.008), with little subsequent change to day29 and day 90. All decreases in D-D, TAT, Il-6 and LDH were sustained in the maintenance phase of treatment (days29–90). Plasma TFMP were detectable and significantly increased in all patients prior to treatment. There was a statistically significant decrease in TFMP by day 8 (p=0.0234) and TFMP levels remained below pretreatment levels for the duration of the study (p=0.030). However, there were wide individual variations in TFMP levels over the course of treatment. There were significant Spearman correlations between changes in D-D and TAT (0.521; p&lt;0.0001), in D-D and IL-6 (0.4400; p=0.0007). Changes in LDH did not correlate with changes in D-D, TAT, TFMP or Il-6. Changes in TFMP did not correlate with changes in markers of thrombin generation (TAT or D-D). Conclusion: Eculizumab treatment of patients with PNH results in a rapid decrease in plasma tissue factor microparticles, thrombin generation and inflammation. These changes appear to be independent of eculizumab suppression of RBC hemolysis as characterized by decreases in serum LDH. A direct relationship between plasma TFMP levels and thrombin generation in PNH patients could not be confirmed in this study. Taken together, these data indicate the broader impact of eculizumab treatment to suppress inflammation and prothrombotic activity in patients with PNH.

Thromboelastometry Shows a Prothrombotic State in Systemic Lupus Erythematosus Related to Diminished Fibrinolysis and Microparticle-Derived Tissue Factor

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 2317-2317
Author(s):  
Ihosvany Fernandez Bello ◽  
Francisco Javier López Longo ◽  
Victor Jiménez Yuste ◽  
Miguel Canales ◽  
Juan Ovalles ◽  
...  
Keyword(s):  
Systemic Lupus Erythematosus ◽  
Tissue Factor ◽  
Lupus Erythematosus ◽  
Thrombin Generation ◽  
Alpha Angle ◽  
Endothelial Damage ◽  
Hypercoagulable State ◽  
Prothrombotic State ◽  
Systemic Lupus ◽  
Pai 1

Abstract Background: Systemic Lupus Erythematosus (SLE) is an autoimmune disorder of unknown origin with a high mortality pattern due to the development of a premature cardiovascular disease. The presence in these patients of a dysfunctional endothelium together with a hypercoagulable milieu may contribute to an increased incidence of thrombotic events. Increased thrombin generation, elevated levels of circulating microparticles and plasmatic levels of PAI-1 may contribute to the prothrombotic phenotype of the disease but data are scarce. Objectives: 1-To characterize the prothrombotic state in SLE by rotational thromboelastometry (ROTEM) and thrombin generation linked to tissue factor bearing microparticles. 2- To evaluate endothelial damage in patients with SLE and its relationship with the prothrombotic state of the disease. 3- To evaluate the influence of PAI-1 in the prothrombotic state of SLE. Material and methods: 39 patients with SLE and 25 sex and age matched healthy subjects were included. Whole blood was drawn in standard BD sodium citrate tubes (3.2%). ROTEM was performed in naTEM condition. Clotting time (CT, time from start of measurement until initiation of clotting [in seconds], alpha angle, which reflects the rate of fibrin polymerisation (tangent to the curve at 2-mm amplitude [in degrees]), maximum clot firmness, which reflects the maximum tensile strength of the thrombus (MCF, [in mm]), the time that clot takes to increase from 2mm above baseline to 20mm above baseline (CFT) and A5, amplitude at 5 min, were recorded. To evaluate the presence of tissue factor bearing microparticles, thrombin generation was determined by Calibrated Automated Thrombogram (CAT) in presence of 4 mM phospholipid (MP-Reagent, Diagnostica Stago, Spain). The endogenous thrombin potential (ETP, the total amount of thrombin generated over time); the lag time (the time to the beginning of the explosive burst of thrombin generation); the peak height of the curve (the maximum thrombin concentration produced); and the time to the peak were evaluated. Antigenic levels of E-selectin and PAI-1 were determined by ELISA (R&D Systems, MN, USA and Affymetrix eBioscience, Vienna, Austria) respectively. Results: ROTEM parameters showed a hypercoagulable profile in LES patients. CT and CFT were shorter (p<0.001 in both cases), and MCF, alpha angle and A5 were higher (p<0.001, p<0.02 and p<0.001 respectively) when compared to healthy controls. On the other hand, CAT parameters did not show differences between both groups. Nevertheless, in LES patients but not in controls, CAT parameters significantly correlated with ROTEM ones (Table 1). Table 1.Correlations in the LES patients group between CAT and ROTEM parameters. Analyses were performed with Spearman test. N: number of determinations; p* denotes significance.CTCFTMCFMCF-talphaA5A10ETP(MP)r-,301-,375*,369*-,368*,378*,364*,393*p,0840,028*0,031*0,032*0,027*0,034*0,021*N34343434343434Peak(MP)r-,353*-,396*,372*-,345*,396*,393*,402*p0,040*0,020*0,030*0,045*0,020*0,021*0,018*N34343434343434ttPeak(MP)r,240,222-,242,217-,223-,209-,210p,171,207,168,217,205,236,232N34343434343434 In order to evaluate endothelial damage, plasma E-selectin and PAI-1 were determined. No differences were found in E-selectin level whereas increased PAI-1 levels were seen in LES group (p<0.006). PAI-1 did not correlate to ROTEM parameters. Conclusions: ROTEM can detect a hypercoagulable state in patients with SLE. The hypercoagulable state may be linked to increased tissue factor bearing microparticles and increased PAI-1 plasma levels. Disclosures No relevant conflicts of interest to declare.

scholarly journals Correlation of Dengue Warning Signs during Febrile Phase with Rotational Thromboelastometry, Cortisol and Feritin

2022 ◽  
Vol 19 (2) ◽  
pp. 807
Author(s):  
Syarifah Syahirah Syed Abas ◽  
Noralisa Abdul Karim ◽  
Petrick Periyasamy ◽  
Nurasyikin Yusof ◽  
Shamsul Azhar Shah ◽  
...  
Keyword(s):  
Platelet Count ◽  
Platelet Function ◽  
Warning Signs ◽  
Clotting Time ◽  
Rotational Thromboelastometry ◽  
Potential Marker ◽  
Kinetics Of ◽  
Platelet Functions ◽  
Maximum Clot Firmness

Dengue mortality remains high despite monitoring against warning signs (WS). The associations of WS at febrile phase (FP) and hemorrhage at defervescence with the levels and kinetics of ROTEM, platelet count, cortisol, and ferritin were analyzed. Patients with confirmed dengue serology and WS in two centers were screened (n = 275) and 62 eligible patients were recruited prospectively over 9 months. “Vomiting” was the commonest WS (62.9%), with shortened clotting time (CT) INTEM (p = 0.01). “Hematocrit increase” showed significant prolonged CT INTEM, EXTEM, and FIBTEM (p < 0.05). “Platelet decrease” showed reduced platelet function and reduced clot amplitude at 10 min (A10) and maximum clot firmness (MCF) in INTEM and EXTEM (p < 0.001). The kinetics were reduced in platelet count, CT EXTEM, and cortisol (p < 0.05) but increased in CT INTEM (p = 0.03). At FP, “vomiting”, “hematocrit increase”, and “platelet decrease” demonstrated impaired CT, clot strengths A10/MCF and platelet functions. Majority (60/62, 96.7%) had non-severe outcomes, consistent with increase in cortisol kinetics. In conclusion, “vomiting”, “hematocrit increase” and “platelet decrease” at FP correlated with ROTEM. No conclusion could be made further regarding ferritin and cortisol. Larger study is required to study “hematocrit increase” with ROTEM as a potential marker for hemorrhage.

scholarly journals The Rate of Prothrombin Conversion Is Increased in Antiphospholipid Syndrome and Is Insensitive to Thrombomodulin

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 718-718
Author(s):  
Romy Kremers ◽  
Stéphane Zuily ◽  
Hilde Kelchtermans ◽  
Tessa Peters ◽  
Saartje Bloemen ◽  
...  
Keyword(s):  
Tissue Factor ◽  
Antiphospholipid Syndrome ◽  
Conversion Rate ◽  
Healthy Subjects ◽  
Thrombin Generation ◽  
Lag Time ◽  
Peak Height ◽  
Thrombin Inhibitors ◽  
Time To Peak ◽  
Glycoprotein I

Abstract Background: The antiphospholipid syndrome (APS) is characterized by the presence of antiphospholipid antibodies directed mainly against prothrombin and β2-glycoprotein I. The syndrome is associated with an increased risk of thrombosis. The global hemostatic state in a patient can be tested by measuring thrombin generation (TG). Recently, we developed a method to study the main pro- and anticoagulant processes at the basis of TG, called the thrombin dynamics method. Aim: In this study we investigated the dynamics of thrombin generation in healthy subjects and APS patients. Materials and methods: Healthy subjects (n=129) and antiphospholipid syndrome (APS) patients (n=31) were included in the study. Sixty-eight percent of the APS patients were lupus anticoagulant positive, anti-cardiolipin antibodies were detected in 84% of the patients, and 52% presented with anti-β2-glycoprotein I antibodies. Patients on anticoagulant therapy were excluded from the study. Thrombin generation was measured at 1 pM tissue factor (TF) and activated protein C (APC) system sensitivity was tested by measuring TG in the presence and absence of 20 nM thrombomodulin (TM). Results: Thrombin generation was measured in platelet poor plasma at 1 pM tissue factor. The lag time and time-to-peak were significantly prolonged in APS patients compared to healthy subjects (lag time: 3.30 ± 0.59 vs. 6.69 ± 4.26 min, p<0.001; time-to-peak: 8.33 ± 1.29 vs. 10.76 ± 4.51 min, p<0.001). The peak height was significantly higher in APS patients (240 ± 84 vs. 214 ± 58 nM, p<0.05) and the velocity index was elevated in APS patients (134 ± 66 vs. 70 ± 32 nM/min, p<0.001) compared to healthy subjects. The ETP values were comparable between healthy subjects and APS patients (1260 ± 235 vs. 1176 ± 362 nM*min). The pro- and anticoagulant processes underlying thrombin generation were studied separately. The total amount of prothrombin converted during thrombin generation (PCtot) did not differ between healthy subjects and patients (1234 vs. 1165 nM). However, the maximum rate of prothrombin conversion (PCmax) was significantly elevated in APS patients (291 vs 425 nM/min; p<0.001). The amount of thrombin-antithrombin (T-AT) complexes formed was comparable between patients and controls (1169 vs. 1098 nM), and the thrombin decay capacity (TDC) was comparable as well (0.675 vs. 0.674 min-1). These results are in line with the finding that the plasma levels of the main thrombin inhibitors are unchanged in APS patients. Antithrombin levels are on average 2.31 ± 0.44 μM in healthy subjects and 2.36 ± 0.56 μM in APS patients, and the mean α2-macroglobulin levels were 3.22 ± 0.77 μM in healthy subjects and 3.23 ± 1.11 μM in patients. Thrombomodulin reduced the ETP by 45% in healthy subjects, but had significantly less effect in APS patients (10%). The addition of TM decreased total prothrombin conversion by 40% and the maximum prothrombin conversion rate by 50% in healthy subjects. In patients, TM only slightly reduced total prothrombin conversion (8%) and the maximum prothrombin conversion rate (7%). Discussion: The thrombin generation results indicate a predisposition to thrombosis in APS patients, as the TG parameters peak height and the velocity index are increased. Examination of the underlying pro- and anticoagulant processes of prothrombin conversion and thrombin inactivation revealed that although the same amount of prothrombin is converted in patients, the maximum activity of the prothrombinase complex is higher, indicating that patients can generate thrombin faster. In addition, APS patients have a dysfunctional APC system, as prothrombin conversion and thrombin generation could be only slightly inhibited by the addition of thrombomodulin. Disclosures No relevant conflicts of interest to declare.

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