Coagulation assessment by rotation thrombelastometry in normal pregnancy

SummaryWe analysed changes in coagulation during normal pregnancy with a novel point-of-care device based on thrombelastometry (ROTEM®). We compared the results obtained with those of standard coagulation tests in 104 patients: 20 non-pregnant women (controls) and 84 women in the first (T1, n=17), second (T2, n=9) and third (T3, n=58) trimesters of pregnancy. We measured the clotting time (CT), the maximum clot firmness (MCF), the early clot amplitude at 5 and 15 minutes (CA5, CA15) and the clot lysis index (CLI30) with four tests containing specific reagents. (a) The INTEM® test involving ellagic acid activated the intrinsic pathway and (b) the EXTEM® test using tissue factor triggered the extrinsic pathway; (c) The FIBTEM® test based on a platelet inhibitor (cytochalasin D) evaluated the contribution of fibrinogen to clot formation and (d) the APTEM® test was similar to the EXTEM but was based on inhibition in vitro of fibrinolysis by aprotinin. CT and CLI30 were not significantly modified during pregnancy whereas MCF, CA5 and CA15 (INTEM, EXTEM, FIBTEM) increased significantly between the second and third trimesters (e.g. median [interquartile range]: MCF-FIBTEM, 13 [11–16] mm vs. 19 [17–23] mm, respectively, in controls and T3, p< 0.001). EXTEM values were not significantly different from those measured with APTEM. There were significant correlations between the results obtained with ROTEM and those from standard coagulation tests. ROTEM analysis showed a marked increase in coagulability during normal pregnancy. ROTEM values may serve as the basis for future studies in pregnant women.

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Molecular Docking, Computational, and Antithrombotic Studies of Novel 1,3,4-Oxadiazole Derivatives

International Journal of Molecular Sciences ◽

10.3390/ijms19113606 ◽

2018 ◽

Vol 19 (11) ◽

pp. 3606 ◽

Cited By ~ 3

Author(s):

Majda Batool ◽

Affifa Tajammal ◽

Firdous Farhat ◽

Francis Verpoort ◽

Zafar Khattak ◽

...

Keyword(s):

Factor Xa ◽

Clot Lysis ◽

Clotting Time ◽

Reference Drug ◽

Docking Score ◽

High Affinity ◽

Oxadiazole Derivatives ◽

Inhibitory Potential

A new series of 1,3,4-oxadiazoles derivatives was synthesized, characterized, and evaluated for their in vitro and in vivo anti-thrombotic activity. Compounds (3a–3i) exhibited significant clot lysis with respect to reference drug streptokinase (30,000 IU), and enhanced clotting time (CT) values (130–342 s) than heparin (110 s). High affinity towards 1NFY with greater docking score was observed for the compounds (3a, 3i, 3e, 3d, and 3h) than the control ligand RPR200095. In addition, impressive inhibitory potential against factor Xa (F-Xa) was observed with higher docking scores (5612–6270) with Atomic Contact Energy (ACE) values (−189.68 to −352.28 kcal/mol) than the control ligand RPR200095 (Docking score 5192; ACE −197.81 kcal/mol). In vitro, in vivo, and in silico results proposed that these newly synthesized compounds might be used as anticoagulant agents.

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Monitoring of Hemostasis by Rotational Thrombelastometry During Normal Pregnancy and Postpartum

Acta Medica Martiniana ◽

10.1515/acm-2015-0006 ◽

2015 ◽

Vol 15 (2) ◽

pp. 5-12 ◽

Cited By ~ 8

Author(s):

L. Duraj ◽

J. Stasko ◽

M. Hasko ◽

P. Chudy ◽

J. Sokol ◽

...

Keyword(s):

Platelet Count ◽

Pregnant Women ◽

Strong Correlation ◽

Blood Donation ◽

Normal Pregnancy ◽

Clotting Factors ◽

Pregnancy And Postpartum ◽

Insight Into ◽

Maximum Clot Firmness

Abstract Background: Rotational thrombelastometry (ROTEM) is a real-time clotting test that provides insight into clotting factors, the fibrinolytic system and platelet function. We obtained the longitudinal values on ROTEM in normal pregnancy and in puerperium. Material and Methods: After ethics committee approval and subject informed consent, citrated blood was sampled from healthy pregnants four times during pregnancy and one time postpartum. As controls we used nonpregnant women undergoing voluntary blood donation. Extem and Intem tests and basic coagulation test were carried out. Results: We included 112 women in our study, 55 non-pregnant women (controls) and 57 healthy pregnants with 5 samplings. The values of maximum clot firmness (MCF - in EXTEM and INTEM) were significantly higher up to 34th-36th week of pregnancy than those in non-pregnant subjects. MCF in 6th-7th week after delivery was significantly higher in both tests. Clotting time (CT) in pregnant women was significantly shorter (EXTEM) compared to non-pregnant subjects. We also found a very strong correlation between MCF and platelet count in all gestational weeks.' Conclusions: Rotation thromboelastometry clearly demonstrates the hypercoagulability in pregnancy and can reflect the higher risk of venous thromboembolism in both pregnancy and puerperium. Strong correlation between MCF and platelet count can suggest role of platelets in hypercoagulability in pregnant women. This study provides a better knowledge about physiological changes in ROTEM measurement during pregnancy and postpartum.

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Interspecies differences in coagulation profile

Thrombosis and Haemostasis ◽

10.1160/th08-02-0103 ◽

2008 ◽

Vol 100 (09) ◽

pp. 397-404 ◽

Cited By ~ 110

Author(s):

Jolanta M. Siller-Matula ◽

Roberto Plasenzotti ◽

Alexander Spiel ◽

Peter Quehenberger ◽

Bernd Jilma

Keyword(s):

Animal Models ◽

Thrombin Generation ◽

Animal Species ◽

Species Differences ◽

Clotting Time ◽

Coagulation Profile ◽

Plasma Measurements ◽

Coagulation And Fibrinolysis ◽

Maximum Clot Firmness

SummaryMany animals are used in research on blood coagulation and fibrinolysis, but the relevance of animal models to human health is often questioned because of differences between species. The objective was to find an appropriate animal species , which mimics the coagulation profile in humans most adequately. Species differences in the coagulation profile with and without thrombin stimulation in vitro were assessed in whole blood by Rotation Thromboelastometry (ROTEM). Endogenous thrombin generation was measured in platelet-poor plasma. Measurements were performed in blood from five different species: humans, rats, pigs, sheep and rabbits. In humans and sheep, the clotting time (ROTEM) was in the same range with or without thrombin stimulation and a 100-fold lower dose of thrombin (0.002 IU) was required to cause a shortening in the clotting time as compared to rats, pigs and rabbits (0.2 IU) (p<0.05).Similarly, the endogenous thrombin potential (ETP) was in the same range in humans and sheep. The maximum clot firmness with or without thrombin stimulation was similar in rabbits and humans. The maximum lysis with or without thrombin stimulation was similar in humans and pigs. Significant species differences exist in the coagulation profile with or without thrombin stimulation. Most importantly, sheep had a clotting time most similar to humans and could thus be a suitable species for translational coagulation studies. Moreover, our findings confirm the potential usefulness of pigs as an experimental species to study fibrinolytic pathway and support the usefulness of rabbits as a species for examining platelets.

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The Defective Down Regulation of Fibrinolysis in Haemophilia A Can Be Restored by Increasing the TAFI Plasma Concentration

Thrombosis and Haemostasis ◽

10.1055/s-0037-1616530 ◽

2001 ◽

Vol 86 (10) ◽

pp. 1035-1039 ◽

Cited By ~ 88

Author(s):

Laurent Mosnier ◽

Ton Lisman ◽

Marijke van den Berg ◽

Karel Nieuwenhuis ◽

Joost Meijers ◽

...

Keyword(s):

Factor Viii ◽

Tissue Factor ◽

Thrombin Generation ◽

Coagulation Factor ◽

Clot Lysis ◽

Haemophilia A ◽

Intrinsic Pathway ◽

Extrinsic Pathway ◽

Down Regulation ◽

Plasma Clot

SummaryTAFI (thrombin activatable fibrinolysis inhibitor) down regulates fibrinolysis after activation by relatively high concentrations of thrombin generated during coagulation via thrombin mediated factor XI activation and subsequent activation of the intrinsic pathway. It is this secondary burst of thrombin that is severely diminished in haemophilia A, a deficiency of coagulation factor VIII. We therefore investigated the role of TAFI in haemophilia A by measuring the clot lysis times of tissue factor induced fibrin formation and tPA mediated fibrinolysis. In haemophilia A plasma clot lysis times were normal at relatively high tissue factor concentrations but severely decreased at moderate to low tissue factor concentrations, indicating that the thrombin generation via the extrinsic pathway was insufficient to activate TAFI. Addition of factor VIII, TAFI or thrombomodulin restored the clot lysis times at low tissue factor concentrations. This confirms the hypothesis that the bleeding disorder in haemophilia A is not merely a defect in the initial clot formation but is in fact a triple defect: reduced thrombin formation via the extrinsic pathway at low tissue factor concentrations, a reduced secondary burst of thrombin generation via the intrinsic pathway and a defective down regulation of the fibrinolytic system by the intrinsic pathway.

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Thrombin activatable fibrinolysis inhibitor and its fibrinolytic effect in normal pregnancy

Thrombosis and Haemostasis ◽

10.1160/th04-06-0387 ◽

2004 ◽

Vol 92 (11) ◽

pp. 1025-1031 ◽

Cited By ~ 48

Author(s):

Hatem Mousa ◽

Colin Downey ◽

Zarko Alfirevic ◽

Cheng-Hock Toh

Keyword(s):

Protein S ◽

Significant Negative Correlation ◽

Normal Pregnancy ◽

Clot Lysis ◽

Thrombin Activatable Fibrinolysis Inhibitor ◽

Significant Drop ◽

Soluble Thrombomodulin ◽

Lysis Time ◽

Fibrinolysis Inhibitor

SummaryWe investigated changes in both thrombin activatable fibrinolysis inhibitor (TAFI) antigen levels and its functional effect on in vitro fibrinolysis in normal pregnancy. 152 pregnant women and 31 women in the immediate postpartum period were studied, with pregnancy divided into 6 windows at 4 weekly intervals. As TAFI influences and is in turn influenced by components of the protein C (PC) pathway, its measurements were correlated with levels of soluble thrombomodulin, PC, protein S (PS) and the overall phenotype of activated PC resistance (APCR). Compared with mean TAFI levels at booking gestation (6.6 +1.2 μg/ml), levels peaked at 35-39 weeks gestation (9.6 +2 μg/ml, p = 0.001), followed by a significant drop within 24 hours of delivery (7.2 + 1.1 μg/ml). In functional terms, the mean clot lysis time (CLT) (101 + 13 min at booking) also peaked at 35-39 weeks gestation (141 + 42 min, p = 0.007) and dropped after delivery (99 + 33 min), and was significantly correlated with gestational age (r = 0.410, p = 0.001) and could be abrogated in the presence of an inhibitor to TAFI activation. A significant negative correlation was found between TAFI levels and APCR (r = −0.478, p <0.001), APCRV (r = −0.598; p <0.001), PS (r = −0.490, P <0.001) and PC (r = −0.198, p = 0.02). In summary, there is a significant increase in TAFI levels, which translates into increased CLT during pregnancy. Furthermore, changes in TAFI contribute to the increasing APCR of pregnancy.

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Antithrombotic potential of Berberis calliobotrys extract

Bangladesh Journal of Pharmacology ◽

10.3329/bjp.v11i4.27054 ◽

2016 ◽

Vol 11 (4) ◽

pp. 776 ◽

Cited By ~ 1

Author(s):

. Alamgeer ◽

Hira Asif ◽

Shahid Rasool

Keyword(s):

Methanolic Extract ◽

In Vitro Studies ◽

Clot Lysis ◽

Clotting Time ◽

Blood Samples ◽

Active Constituents ◽

Significant Prolongation ◽

Phytochemical Studies

This study was focused with the aim to investigate the antithrombotic potential of Berberis calliobotrys. Aqueous-methanolic extract and various fractions showed significant (p<0.05-0.001) increase in prothrombin, activated partial thromboplastin and clotting time while only aqueous methanolic extract caused clot lysis when added to the blood samples of rabbit and human. In vivo study in rabbits, butanolic fraction (100 mg/kg) produced more significant prolongation in bleeding, prothrombin, activated partial thromboplastin and clotting time. Interestingly butanolic fraction had shown more pronounced effects among all tested extracts both in vivo and in vitro studies. Hence, it was subjected to antilipid peroxidation and phytochemical studies (total falvonoid contents, HPLC-DAD profile, FTIR). In conclusion, B. calliobotrys induce transient changes in the coagulation parameters, may it possess active constituents responsible for its antithrombotic potential.

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CLOT STIFFNESS MEASURED BY SEER SONORHEOMETRY AS A MARKER OF POOR PROGNOSIS IN HOSPITALIZED COVID-19 PATIENTS

10.1101/2021.07.13.21260256 ◽

2021 ◽

Author(s):

Francisco Jose Lopez-Jaime ◽

Sandra Martin-Tellez ◽

Alberto Doblas-Marquez ◽

Ignacio Marquez-Gomez ◽

Jose Maria Reguera-Iglesias ◽

...

Keyword(s):

Hospital Admission ◽

Disease Severity ◽

Poor Prognosis ◽

Point Of Care ◽

Clot Lysis ◽

Thrombotic Complication ◽

Inflammation Markers ◽

Clinical Value ◽

Coagulation Tests ◽

D Dimer

Background: High incidence of life-threatening thrombotic complications is observed in severely ill COVID-19 patients. D-dimer may help evaluate disease severity and predict outcomes at hospital admission. However, its non-specificity and long analysis times strongly constrain its clinical value. Viscoelastic tests (VET) are widely available rapid point-of-care devices that have been shown to detect a hypercoagulable state (increased clot stiffness and fibrinolysis shutdown) as major contributors of the thrombotic complication in COVID-19. Nevertheless, based on the data obtained so far, definitive conclusions have not been drawn. Objectives: We aim to evaluate the association between VET parameters, standard coagulation tests and inflammation markers assessed in COVID-19 patients at hospital admission with disease severity and outcomes. Patients/Methods: A total of 69 COVID-19 patients requiring hospitalization were included in the study. The pro-inflammatory and pro-thrombotic state was analyzed by a panel of inflammation markers (IL-6, CRP, LDH, ferritin), routine coagulation tests (PT, aPTT, platelet count, fibrinogen, D-dimer) and a SEER sonorheometry VET profile (Quantra System). Results: Inflammatory markers IL-6, CRP, LDH and ferritin were elevated in a high percentage of patients (73.6%, 89.2%, 57.1% and 52.4%), as were coagulation-related parameters such as fibrinogen (81.4%) and D-dimer levels (66.2%). Quantra analysis revealed increased clot stiffness (CS) in 34.8%, particularly due to increased fibrinogen contribution (FCS) in 63.7%. Increased clot stability to lysis (CSL) was observed in 32.4%. Age > 65 years, elevated values of fibrinogen, D-dimer, LDH, increased clot stiffness and resistance to clot lysis were significantly associated with worsening disease. The Quantra FCS parameter showed a particularly high prognostic value in distinguishing patients with severe symptomatology. Conclusion: The global study of hemostasis by the whole blood point-of-care Quantra VET system may be a powerful tool for identifying poor prognosis in COVID-19 patients at hospital admission. In particular, FCS measured by Quantra could be established as a plausible prognostic marker to aid the clinical management of COVID-19 patients.

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Flow Cytometric Detection of Circulating Activated Platelets and Platelet Hyper-Responsiveness in Pre-Eclampsia and Pregnancy

Clinical Science ◽

10.1042/cs0860731 ◽

1994 ◽

Vol 86 (6) ◽

pp. 731-739 ◽

Cited By ~ 69

Author(s):

Sarah L. Janes ◽

Alison H. Goodall

Keyword(s):

Pregnant Women ◽

Ex Vivo ◽

Antigen Expression ◽

Normal Pregnancy ◽

Control Group ◽

Fibrinogen Binding ◽

Low Concentrations ◽

Granule Membrane ◽

Cd63 Expression

1. Platelet activation status and response to stimulation with agonists ex vivo were studied by whole blood flow cytometry in 15 women with pre-eclampsia, 20 age- and gestational-age-matched women who completed a normal pregnancy, and 20 age-matched non-pregnant women. 2. Women with proteinuric pre-eclampsia showed evidence of activated, degranulated platelets in the circulation, with increased platelet-bound fibrinogen, increased expression of the lysosomal granule membrane antigen, CD63, and raised plasma levels of β-thromboglobulin. 3. CD63 expression and β-thromboglobulin per platelet were also significantly higher in normal pregnant women than in non-pregnant women, but in these subjects fibrinogen binding was normal. 4. There was good correlation for all subjects in degranulation, measured by CD63 antigen expression, and by plasma β-thromboglobulin levels corrected for platelet count (r = 0.65; P < 0.01). 5. Platelet responsiveness to ADP in vitro showed a heightened degranulation response (CD63 expression) in normal pregnancy compared with the non-pregnant control group, which was increased further in women with non-proteinuric and proteinuric pre-eclampsia. 6. However, this response was not accompanied by an increased binding of fibrinogen to GPIIb—IIIa. Fibrinogen binding in response to ‘weak’ agonist stimulation, by low concentrations of ADP or, in a subgroup by adrenaline, was in fact lower in the normal pregnant women than in the non-pregnant women. 7. It is postulated that women at risk of developing pre-eclampsia may have hyper-reactive platelets, primed to undergo release by passage through the abnormal placenta.

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In-Vitro Evaluation of the Multiple Coagulation Test System (MCTS).

Blood ◽

10.1182/blood.v110.11.2907.2907 ◽

2007 ◽

Vol 110 (11) ◽

pp. 2907-2907

Author(s):

William C. Oliver ◽

Gregory A. Nuttall ◽

Sheldon Goldstein ◽

Mark H. Ereth ◽

Jeffrey L. Winters ◽

...

Keyword(s):

Analysis Of Variance ◽

Whole Blood ◽

Point Of Care ◽

Plasma Concentrations ◽

Coagulation Parameters ◽

Coagulation Tests ◽

Blood Constituent ◽

The Mean ◽

The Relationship

Abstract A device that would provide a rapid evaluation of hemostasis would greatly aid physicians in making scientific decisions regarding transfusion therapy; especially with perioperative bleeding. We performed a prospective in-vitro study with reconstituted, recalcified whole blood (n = 6) separated into samples containing specific deficiencies in platelets, plasma, lyophilized platelets and lyophilized plasma such that the concentrations of the specific platelet or plasma were 0%, 10%, 30%, 50%, and 100%. The whole blood was obtained from consenting healthy volunteers. Samples from the various concentrations of the reconstituted blood were subjected to the following point of care coagulation tests: activated clotting time (ACT), thromboelastogram (TEG), laboratory prothrombin time (PT), laboratory activated partial thromboplastin time (APTT) and Signature+ PT. ACT’s were performed for each of four celite doses (1.5 mg, 3.0 mg, 6.0 mg and 12 mg celite). The four dose celite ACT’s were performed in duplicate and the mean recorded. The TEG was performed in duplicate, and the mean was recorded. The signature+ PT was performed in duplicate, and the mean recorded. The laboratory PT, aPTT, Platelet Count and Fibrinogen were performed once each. ACT values were analyzed within each of the three preparations using analysis of variance. This assessed the strength of the relationship between blood constituent concentration and ACT, and determined whether this relationship differed across varying amounts of celite. Other coagulation parameters including TEG (mA), PT and APTT were analyzed using analysis of variance with a single term for blood constituent concentration. This model determined the strength of the relationship between these coagulation parameters and blood constituent concentration. In addition, the kaolin activated TEG and the signature+ PT was evaluated to determine the strength of the relationship between these tests and the variations in platelet and plasma concentrations. There was a significant correlation between the plasma, platelets and lyophilized plasma concentrations and ACT results (all p < 0.001). There was a significant correlation between plasma platelets and lyophilized plasma and the TEG MA and angle (all p < 0.028). There was a significant correlation between laboratory PT and APTT and plasma, platelets, and lyophilized plasma, lyophilized platelets (all p < 0.001). There was a significant correlation between the Signature+ PT and plasma, lyophilized platelets, and lypholized plasma and platelets (all p < 0.005), (figure 1). A better point of care coagulation device that is based on in-vitro additions of various therapies, and comparison of their effects on coagulation tests may provide better treatment of the bleeding patient. The Signature+ PT could provide the endpoint for such a device whereas the ACT was nonspecific and had a small change in results with large changes in plasma concentration. The additional benefit of lypholized plasma to behave similarly to human plasma may allow such a device to be built. Figure Figure

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Diurnal Rhythm in Anticoagulant Effect of Heparin during a Low Dose Constant Rate Infusion

Thrombosis and Haemostasis ◽

10.1055/s-0038-1656312 ◽

1992 ◽

Vol 68 (01) ◽

pp. 030-032 ◽

Cited By ~ 15

Author(s):

J W M Krulder ◽

A de Boer ◽

A M H P van den Besselaar ◽

A F Cohen ◽

H C Schoemaker ◽

...

Keyword(s):

Control Experiment ◽

Plasma Concentrations ◽

Anticoagulant Effect ◽

Diurnal Rhythms ◽

Clotting Time ◽

Platelet Factor ◽

Constant Rate ◽

Coagulation Tests ◽

Rate Infusion

SummaryThe objective of the study was to investigate possible diurnal rhythms in coagulation tests during a continuous intravenous infusion of unfractionated heparin. Six volunteers participated in the study, which was divided in a treatment (500 U heparin/h for 30 h) and a control experiment. Under basal conditions, no rhythm was found in coagulation tests. During heparin treatment, APTT, thrombin clotting time and anti-Xa activity showed a greater anticoagulant effect at night, with a striking decrease in the morning.In a search for the explanation of this phenomenon we looked for diurnal variations in the urinary excretion of heparin, in the plasma concentrations of antithrombin III and platelet factor 4, and in the effect of heparin added to the plasma samples in vitro. None of these studies provided the explanation.

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