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Akbalut C, Arisz R, Baaten C, Baildildinova G, Barakzie A, Bauersachs R, Ten Berg JM, van den Broek W, de Boer HC, Broker V, Buka R, Ten Cate H, Cate AT, De Luca C, De Simone I, Dignat-George F, Freson K, Gazzaniga G, van Gorp E, Habibi A, Henskens YMC, Iding AFJ, Khan A, Koenderink G, Konkoth A, Lacroix R, Lahiri T, Lam W, Lamerton R, Lorusso R, Luo Q, Maas C, McCarty OJT, van der Meijden P, Meijers J, Mohapatra A, Nevo N, Pallares Robles A, Poncelet P, Reinhardt C, Ruf W, Saraswat R, Schonichen C, Schutgens REG, Simioni P, Spada S, Spronk HMH, Tazhibayeva K, Thachil J, Vacik-Diaz R, Veninga A, Verhamme P, Visser C, Watson SP, Wenzel P, Willems R, Willers A, Zhang P, Zifkos K, van Zonneveld AJ. Blood coagulation and beyond: Position paper from the Fourth Maastricht Consensus Conference on Thrombosis. Thromb Haemost 2023. [PMID: 36913975 PMCID: PMC10365887 DOI: 10.1055/a-2052-9175] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/14/2023]
Abstract
The 4th Maastricht Consensus Conference on Thrombosis (MCCT), included the following themes: Theme 1: The "coagulome" as a critical driver of cardiovascular disease Blood coagulation proteins also play divergent roles in biology and pathophysiology, related to specific organs, including brain, heart, bone marrow and kidney. Four investigators shared their views on these organ-specific topics. Theme 2: Novel mechanisms of thrombosis Mechanisms linking factor XII to fibrin, including their structural and physical properties, contribute to thrombosis, which is also affected by variation in microbiome status. Virus infections associated-coagulopathies perturb the hemostatic balance resulting in thrombosis and/or bleeding. Theme 3: How to limit bleeding risks: insights from translational studies This theme included state of the art methodology for exploring the contribution of genetic determinants of a bleeding diathesis; determination of polymorphisms in genes that control the rate of metabolism by the liver of P2Y12 inhibitors, to improve safety of antithrombotic therapy. Novel reversal agents for direct oral anticoagulants are discussed. Theme 4: Hemostasis in extracorporeal systems: how to utilize ex vivo models? Perfusion flow chamber and nanotechnology developments are developed for studying bleeding and thrombosis tendencies. Vascularised organoids are utilized for disease modeling and drug development studies. Strategies for tackling extracorporeal membrane oxygenation (ECMO) associated coagulopathy are discussed. Theme 5: Clinical dilemmas in thrombosis and antithrombotic management Plenary presentations addressed controversial areas, ie thrombophilia testing, thrombosis risk assessment in hemophilia, novel antiplatelet strategies and clinically tested factor XI(a) inhibitors,both possibly with reduced bleeding risk. Finally, Covid-19 associated coagulopathy is revisited.
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Affiliation(s)
- Cengiz Akbalut
- Biochemistry, Maastricht University Cardiovascular Research Institute Maastricht, Maastricht, Netherlands
| | | | - Constance Baaten
- Maastricht University Medical Center, Maastricht, Netherlands.,Uniklinik RWTH Aachen, Aachen, Germany
| | | | | | - Rupert Bauersachs
- Department of Vascular Medicine, Cardioangiologisches Centrum Bethanien, Frankfurt, Germany.,Center for Vascular Research, Germany
| | | | | | - Hetty C de Boer
- Dept. of Nephrology, Leiden University Medical Center, Leiden, Netherlands
| | - Vanessa Broker
- Biochemistry, Maastricht University, Maastricht, Netherlands.,Center for Thrombosis and Hemostasis, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Richard Buka
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, United Kingdom of Great Britain and Northern Ireland
| | - Hugo Ten Cate
- Thrombosis Expert Center and departments of Internal medicine and Biochemistry, Maastricht University Medical Centre+, Maastricht, Netherlands.,Center for Thrombosis and Hemostasis, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Arina Ten Cate
- UNS 50/box 8, University Medical Center, Maastricht, Netherlands
| | - Ciro De Luca
- Dipartimento di Salute Mentale e Fisica e Medicina Preventiva, Università degli Studi della Campania Luigi Vanvitelli, Napoli, Italy
| | - Ilaria De Simone
- Biochemistry, Maastricht University, Maastricht, Netherlands.,Institute for Cardiovascular and Metabolic Research, University of Reading, Reading, United Kingdom of Great Britain and Northern Ireland
| | - Françoise Dignat-George
- INSERM, VRCM, UMR-S1076,, Aix-Marseille University, UFR de Pharmacie, Marseille, France, Marseille, France
| | - Kathleen Freson
- Department of Cardiovascular Sciences, Center for Molecular and Vascular Biology, Katholieke Universiteit Leuven, Leuven, Belgium
| | - Giulia Gazzaniga
- Cardiothoracic Surgery, Maastricht University Medical Centre+, Maastricht, Netherlands
| | | | - Anxhela Habibi
- Biochemistry, Maastricht University, Maastricht, Netherlands
| | | | - Aaron F J Iding
- Biochemistry, Maastricht University Cardiovascular Research Institute Maastricht, Maastricht, Netherlands
| | - Abdullah Khan
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, United Kingdom of Great Britain and Northern Ireland.,MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom of Great Britain and Northern Ireland
| | - Gijsje Koenderink
- Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, Netherlands
| | - Akhil Konkoth
- Biochemistry, Maastricht University, Maastricht, Netherlands.,C2VN Inserm, Aix-Marseille Universite, Marseille, France
| | - Romaric Lacroix
- Inserm UMR-S1076, UFR de Pharmacie, Aix Marseille Université, Marseille, France
| | - Trisha Lahiri
- Center for Thrombosis and Hemostasis, Johannes Gutenberg Universität Mainz, Mainz, Germany.,C2VN Inserm, Aix-Marseille Universite, Marseille, France
| | - Wilbur Lam
- Emory University, Atlanta, United States
| | - Rachel Lamerton
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, United Kingdom of Great Britain and Northern Ireland
| | - Roberto Lorusso
- Cardiovascular Centre, Maastricht University Medical Centre+, Maastricht, Netherlands.,Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, Netherlands
| | - Qi Luo
- Center for Thrombosis and Hemostasis, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany.,Biochemistry, Maastricht University, Maastricht, Netherlands
| | - Coen Maas
- University Medical Center Utrecht, Clinical Chemistry and Hematology, Utrecht University, Utrecht, Netherlands
| | - Owen J T McCarty
- Biomedical Engineering, Oregon Health & Science University, Portland, United States
| | | | | | - Adarsh Mohapatra
- Biochemistry, Maastricht University, Maastricht, Netherlands.,IMCAR, University Hospital Aachen, Aachen, Germany.,C2VN Inserm, Aix-Marseille Universite, Marseille, France
| | - Neta Nevo
- Immunology, Weizmann Institute of Science, Rehovot, Israel.,Immunology, Technion Israel Institute of Technology, Haifa, Israel
| | - Alejandro Pallares Robles
- Department of Biochemistry, Maastricht University Cardiovascular Research Institute Maastricht, Maastricht, Netherlands.,Center of Thrombosis and Hemostasis, Johannes Gutenberg University Mainz, Mainz, Germany
| | | | - Christoph Reinhardt
- Center for Thrombosis and Haemostasis, University Medical Center Mainz, Mainz, Germany
| | - Wolfram Ruf
- Center for Thrombosis and Hemostasis, Johannes Gutenberg Universitat Universitatsmedizin, Mainz, Germany
| | - Ronald Saraswat
- Center for Thrombosis and Hemostasis, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany.,C2VN Inserm, Aix-Marseille Universite, Marseille, France
| | - Claudia Schonichen
- Biochemistry, Maastricht University, Maastricht, Netherlands.,Center for Thrombosis and Hemostasis, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | | | - Paolo Simioni
- Dep of Cardiological, Thoracic and Vascular Sciences, University of Padua ; 2nd Chair of Internal Medicine, Padua, Italy
| | - Stefano Spada
- Biochemistry, Maastricht University, Maastricht, Netherlands.,Center for Thrombosis and Hemostasis, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Henri M H Spronk
- Internal Medicine, Cardiovascular Research Institute Maastricht, Maastricht University Medical Center, Maastricht, Netherlands.,Thrombosis Expert Center, Maastricht University Medical Centre+, Maastricht, Netherlands
| | | | - Jecko Thachil
- Haematology, Central Manchester and Manchester Children's University Hospitals NHS Trust, Manchester, United Kingdom of Great Britain and Northern Ireland
| | - Rocio Vacik-Diaz
- Center for Thrombosis and Hemostasis, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany.,C2VN Inserm, Aix-Marseille Universite, Marseille, France
| | - Alicia Veninga
- Biochemistry, Maastricht University, Maastricht, Netherlands
| | - Peter Verhamme
- Center for Molecular and Vascular Biology, KULeuven, Leuven, Belgium
| | - Chantal Visser
- Hematology, Erasmus Medical Center, Rotterdam, Netherlands
| | - Steve P Watson
- University of Birmingham, Birmingham, United Kingdom of Great Britain and Northern Ireland
| | - Philip Wenzel
- Zentrum für Kardiologie - Centrum für Thrombose und Hämostase, Universitätsmedizin der Johannes Gutenberg-Universität Mainz, Mainz, Germany.,Center for Thrombosis and Hemostasis, Universitätsmedizin der Johannes Gutenberg-Universität Mainz, Mainz, Germany
| | - Ruth Willems
- Biochemistry and Internal Medicine, Maastricht University Medical Centre+, Maastricht, Netherlands.,Research, Synapse Research Institute, Maastricht, Netherlands
| | - Anne Willers
- Cardiothoracic Surgery, Maastricht University Medical Centre+, Maastricht, Netherlands
| | - Pengyu Zhang
- Biochemistry, Maastricht University, Maastricht, Netherlands.,ISAS Leibniz Institute for Analytical Sciences, Dortmund, Germany
| | - Konstantinos Zifkos
- Center for Thrombosis and Hemostasis, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
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Lisman T, Adelmeijer J, Huskens D, Meijers J. APROTININ INHIBITS THROMBIN GENERATION BY THE INTRINSIC PATHWAY OF COAGULATION, BUT IS NOT A DIRECT THROMBIN INHIBITOR. J Cardiothorac Vasc Anesth 2021. [DOI: 10.1053/j.jvca.2021.08.088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Delvasto L, Roem D, Bakhtiari K, van Mierlo GJ, Meijers J, Jongerius I, Zeerleder SS. Iron-driven alterations on red blood cell-derived microvesicles amplify coagulation during hemolysis via the intrinsic tenase complex. Thromb Haemost 2021; 122:80-91. [PMID: 33940654 DOI: 10.1055/a-1497-9573] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Hemolytic disorders characterized by complement-mediated intravascular hemolysis, such as autoimmune hemolytic anemia and paroxysmal nocturnal hemoglobinuria, are often complicated by life-threatening thromboembolic complications. Severe hemolytic episodes result in the release of red blood cell (RBC)-derived pro-inflammatory and oxidatively reactive mediators (e.g. extracellular hemoglobin, heme and iron) into plasma. Here, we studied the role of these hemolytic mediators in coagulation activation by measuring FXa and thrombin generation in the presence of RBC lysates. Our results show that hemolytic microvesicles (HMVs) formed during hemolysis stimulate thrombin generation through a mechanism involving FVIII and FIX, the so-called intrinsic tenase complex. Iron scavenging during hemolysis using deferoxamine decreased the ability of the HMVs to enhance thrombin generation. Furthermore, the addition of ferric chloride (FeCl3) to plasma propagated thrombin generation in a FVIII and FIX-dependent manner suggesting that iron positively affects blood coagulation. Phosphatidylserine (PS) blockade using lactadherin and iron chelation using deferoxamine reduced intrinsic tenase activity in a purified system containing HMVs as source of phospholipids confirming that both PS and iron ions contribute to the procoagulant effect of the HMVs. Finally, the effects of FeCl3 and HMVs decreased in the presence of ascorbate and glutathione indicating that oxidative stress plays a role in hypercoagulability. Overall, our results provide evidence for the contribution of iron ions derived from hemolytic RBCs to thrombin generation. These findings add to our understanding of the pathogenesis of thrombosis in hemolytic diseases.
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Affiliation(s)
| | | | | | | | | | - Ilse Jongerius
- Sanquin Research, Amsterdam, Netherlands.,Department of Pediatric Immunology, Rheumatology and Infectious Diseases, Amsterdam UMC Locatie AMC, Amsterdam, Netherlands
| | - Sacha S Zeerleder
- Department of Immunopathology, Sanquin-AMC Landsteiner Laboratory, Amsterdam, Netherlands.,Department of Hematology, Academic Medical Center, Amsterdam, Netherlands
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Visman I, Heslinga M, van Denderen C, van der Horst-Bruinsma I, Miltenburg A, Meijers J, Nurmohamed M. Favorable effects on the hemostatic system in ankylosing spondylitis patients treated with golimumab. Joint Bone Spine 2020; 88:105102. [PMID: 33166729 DOI: 10.1016/j.jbspin.2020.105102] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 10/23/2020] [Indexed: 11/16/2022]
Affiliation(s)
- Ingrid Visman
- Amsterdam Rheumatology and immunology Center
- Reade, Amsterdam, Jan van Breemenstraat 2, 1056 AB Amsterdam, The Netherlands.
| | - Maaike Heslinga
- Amsterdam Rheumatology and immunology Center
- Reade, Amsterdam, Jan van Breemenstraat 2, 1056 AB Amsterdam, The Netherlands
| | - Christiaan van Denderen
- Amsterdam Rheumatology and immunology Center
- Reade, Amsterdam, Jan van Breemenstraat 2, 1056 AB Amsterdam, The Netherlands
| | - Irene van der Horst-Bruinsma
- Amsterdam Rheumatology and immunology Center
- Amsterdam University Medical Center location VUmc, Amsterdam, The Netherlands
| | | | - Joost Meijers
- Amsterdam UMC, University of Amsterdam, Department of Experimental Vascular Medicine, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands; Department of Molecular and Cellular Hemostasis, Sanquin Research, Amsterdam, The Netherlands
| | - Michael Nurmohamed
- Amsterdam Rheumatology and immunology Center
- Reade, Amsterdam, Jan van Breemenstraat 2, 1056 AB Amsterdam, The Netherlands; Amsterdam Rheumatology and immunology Center
- Amsterdam University Medical Center location VUmc, Amsterdam, The Netherlands
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Ariens R, Becattini C, Bender M, Bergmeier W, Castoldi E, Devreese K, Ellis M, Gailani D, Ignjatovic V, James PD, Kerrigan S, Lambert M, Lee LH, Levi M, Maugeri N, Meijers J, Melero-Martin J, Michelson AD, Mingozzi F, Neeves K, Ni H, Olsson AK, Prohászka Z, Ranson M, Riva N, Senis Y, van Ommen CH, Vaughan DE, Weisel J. Illustrated State-of-the-Art Capsules of the ISTH 2020 Congress. Res Pract Thromb Haemost 2020; 4:680-713. [PMID: 32685876 PMCID: PMC7354406 DOI: 10.1002/rth2.12368] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 03/25/2020] [Accepted: 05/08/2020] [Indexed: 01/19/2023] Open
Abstract
The 2020 Congress of the International Society of Thrombosis and Haemostasis (ISTH) was held virtually July 12-15, 2019, due to the coronavirus disease 2019 pandemic. The congress convenes annually to discuss clinical and basic topics in hemostasis and thrombosis. Each year, the program includes State of Art (SOA) lectures given by prominent scientists. Presenters are asked to create Illustrated Capsules of their talks, which are concise illustrations with minimal explanatory text. Capsules cover major themes of the presentation, and these undergo formal peer review for inclusion in this article. Owing to the shift to a virtual congress this year, organizers reduced the program size. There were 39 SOA lectures virtually presented, and 29 capsules (9 from talks omitted from the virtual congress) were both submitted and successful in peer review, and are included in this article. Topics include the roles of the hemostatic system in inflammation, infection, immunity, and cancer, platelet function and signaling, platelet function disorders, megakaryocyte biology, hemophilia including gene therapy, phenotype tests in hemostasis, von Willebrand factor, anticoagulant factor V, computational driven discovery, endothelium, clinical and basic aspects of thrombotic microangiopathies, fibrinolysis and thrombolysis, antithrombotics in pediatrics, direct oral anticoagulant management, and thrombosis and hemostasis in pregnancy. Capsule authors invite virtual congress attendees to refer to these capsules during the live presentations and participate on Twitter in discussion. Research and Practice in Haemostasis and Thrombosis will release 2 tweets from @RPTHJournal during each presentation, using #IllustratedReview, #CoagCapsule and #ISTH2020. Readers are also welcome to utilize capsules for teaching and ongoing education.
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Affiliation(s)
- Robert Ariens
- Discovery and Translational Science Department Leeds Institute of Cardiovascular and Metabolic Medicine University of Leeds Leeds UK
| | - Cecilia Becattini
- Internal and Cardiovascular Medicine - Stroke Unit University of Perugia Perugia Italy
| | - Markus Bender
- Institute of Experimental Biomedicine - Chair I University Hospital and Rudolf Virchow Center Würzburg Germany
| | - Wolfgang Bergmeier
- Department of Biochemistry and Biophysics UNC Blood Research Center University of North Carolina at Chapel Hill Chapel Hill NC USA
| | - Elisabetta Castoldi
- Cardiovascular Research Institute Maastricht (CARIM) Maastricht University Maastricht The Netherlands
| | - Katrien Devreese
- Coagulation Laboratory Department of Laboratory Medicine Ghent University Hospital Ghent University Ghent Belgium
- Coagulation Laboratory Department of Diagnostic Sciences Ghent University Hospital Ghent University Ghent Belgium
| | - Martin Ellis
- Hematology Institute and Blood Bank Meir Medical Center and Sackler School of Medicine Tel Aviv University Tel Aviv Israel
| | - David Gailani
- Department of Pathology, Microbiology and Immunology Vanderbilt University Medical Center Nashville TN USA
| | - Vera Ignjatovic
- Haematology Research Team Murdoch Children's Research Institute Department of Paediatrics The University of Melbourne Parkville Vic. Australia
| | | | - Steven Kerrigan
- Royal College of Surgeons in Ireland School of Pharmacy and Biomolecular Sciences Irish Centre for Vascular Biology Dublin Ireland
| | - Michele Lambert
- Department of Pediatrics Perelman School of Medicine at the University of Pennsylvania Philadelphia PA USA
| | - Lai Heng Lee
- Department of Haematology Singapore General Hospital SingHealth Singapore City Singapore
| | - Marcel Levi
- University College London Hospitals London UK
| | - Norma Maugeri
- San Raffaele Scientific Institute and Vita-Salute San Raffaele University Milano Italy
| | - Joost Meijers
- Department of Experimental Vascular Medicine Amsterdam University Medical Centers University of Amsterdam Amsterdam The Netherlands
- Department of Molecular and Cellular Hemostasis Sanquin Research Amsterdam The Netherlands
| | | | - Alan D Michelson
- Boston Children's Hospital and Harvard Medical School Boston MA USA
| | | | - Keith Neeves
- Department of Chemical and Biological Engineering Colorado School of Mines Golden CO USA
| | - Heyu Ni
- Department of Laboratory Medicine and Keenan Research Centre for Biomedical Science of St. Michael's Hospital University of Toronto Toronto ON Canada
| | - Anna-Karin Olsson
- Department of Medical Biochemistry and Microbiology Uppsala University Uppsala Sweden
| | - Zoltán Prohászka
- Research Laboratory 3rd Department of Internal Medicine MTA-SE Research Group of Immunology and Hematology Hungarian Academy of Sciences and Semmelweis University Budapest Hungary
| | - Marie Ranson
- School of Chemistry and Molecular Bioscience University of Wollongong Wollongong NSW Australia
| | - Nicoletta Riva
- Department of Pathology Faculty of Medicine and Surgery University of Malta Msida Malta
| | - Yotis Senis
- Directeur de Recherche Etablissement Français du Sang Grand Est Inserm UMR-S1255 Université de Strasbourg Strasbourg France
| | - Cornelia H van Ommen
- Department of Pediatric Hematology Oncology Erasmus MC Sophia Children's Hospital Rotterdam The Netherlands
| | | | - John Weisel
- Department of Cell and Developmental Biology Perelman School of Medicine University of Pennsylvania Philadelphia PA USA
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von dem Borne P, Meijers J, Bouma B, Mosnier L. Plasma TAFI Levels Influence the Clot Lysis Time in Healthy Individuals in the Presence of an Intact Intrinsic Pathway of Coagulation. Thromb Haemost 2017. [DOI: 10.1055/s-0037-1615366] [Citation(s) in RCA: 123] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
SummaryThrombin Activatable Fibrinolysis Inhibitor (TAFI) is a recently identified fibrinolysis inhibitor in plasma, that when converted to an enzyme potently attenuates fibrinolysis. It is activated by relatively high concentrations of thrombin that exceed the thrombin concentration required for fibrin formation. These high concentrations of thrombin are generated by the intrinsic pathway via activation of factor XI by thrombin. The down regulation of fibrinolysis by TAFI can be measured in a clot lysis assay. When the clot lysis times of healthy individuals were determined, large inter-individual differences were observed. To determine if differences in concentration of TAFI explain the variation in clot lysis between individuals, specific assays were developed for the measurement of TAFI antigen and activity in plasma. In normal plasma, there was a dose-dependent relationship between TAFI antigen and TAFI activity. There was also a correlation between clot lysis time and plasma TAFI antigen, indicating that the amount of TAFI that is activated during the clot lysis assay, is dependent on the concentration of TAFI. In the plasmas of 20 healthy individuals, clot lysis times, TAFI antigen and TAFI activity were determined. Both TAFI antigen and TAFI activity showed a significant correlation with the clot lysis time. No correlation between TAFI antigen and clot lysis time was found when the clot lysis time was determined in the presence of an antibody blocking the factor XI feedback loop. These results indicate that plasma TAFI levels influence the clot lysis time in healthy individuals in the presence of an intact intrinsic pathway of coagulation.Abbreviations: The abbreviations used are: TAFI, Thrombin Activatable Fibrinolysis Inhibitor; TAFIa, activated TAFI; CPI, carboxypeptidase inhibitor from potato tubers; CPN, carboxypeptidase N; tPA, tissue-type plasminogen activator.
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van de Poel R, Meijers J, Bouma B. C4b-binding Protein Inhibits the Factor V-dependent but not the Factor V-independent Cofactor Activity of Protein S in the Activated Protein C-mediated Inactivation of Factor VIIIa. Thromb Haemost 2017. [DOI: 10.1055/s-0037-1615714] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
SummaryActivated protein C (APC) is an important inactivator of coagulation factors Va and VIIIa. In the inactivation of factors Va and VIIIa, protein S serves as a cofactor to APC. Protein S can bind to C4b-binding protein (C4BP), and thereby loses its cofactor activity to APC. By modulating free protein S levels, C4BP is an important regulator of protein S cofactor activity. In the factor VIIIa inactivation, protein S and factor V act as synergistic cofactors to APC. We investigated the effect of C4BP on both the factor V-independent and factor V-dependent cofactor activity of protein S in the factor VIIIa inactivation using a purified system. Protein S increased the APC-mediated inactivation of factor VIIIa to 60% and in synergy with protein S, factor V at equi-molar concentrations increased this effect further to 90%. The protein S/factor V synergistic effect was inhibited by preincubation of protein S and factor V with a four-fold molar excess of C4BP. However, C4BP did not inhibit the factor V-independent protein S cofactor activity in the purified system whereas it inhibited the cofactor activity in plasma. We conclude that C4BP-bound protein S retains its cofactor activity to APC in the factor VIIIa inactivation.
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Wagenaar G, Reijerkerk A, Tiekstra M, van Rossum A, Gebbink M, Meijers J, Marx P. Characterization of Mouse Thrombin-activatable Fibrinolysis Inhibitor. Thromb Haemost 2017. [DOI: 10.1055/s-0037-1613802] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
SummaryBased on in vitro studies, thrombin-activatable fibrinolysis inhibitor (TAFI) has been hypothesized as a link between coagulation and fibrinolysis, but the physiological role of TAFI in vivo has not yet been established. To anticipate on the availability of genetically modified mouse models, we studied the endogenous expression of TAFI in mice. Functional TAFI was found in mouse plasma. TAFI mRNA was only detectable in the liver, showing a hepatocyte-specific expression with a pericentral lobular distribution pattern. The murine TAFI cDNA was cloned and sequenced. The deduced amino acid sequence revealed that murine TAFI is highly identical to human TAFI. The murine cDNA was stably expressed and the activated recombinant protein was functionally active; it converted the substrate hippuryl-arginine, and prolonged the clot lysis time of TAFI depleted plasma. We conclude that mice have functional TAFI in plasma, which is highly similar to human TAFI. Therefore, genetically modified mice may provide useful models to study the role of TAFI in vivo.
Abbreviations: TAFI, thrombin-activatable fibrinolysis inhibitor; CPI, carboxypeptidase inhibitor from potato tubers; CPN, carboxypeptidase N; t-PA, tissue-type plasminogen activator; PPACK, H-D-Phe-Pro-Arg-chloromethylketone.
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Middeldorp S, Tekelenburg W, van den Ende A, Tans G, Prins M, Rosing J, Büller H, Bouma B, Meijers J. Increased Fibrinolytic Activity during Use of Oral Contraceptives Is Counteracted by an Enhanced Factor XI-independent down Regulation of Fibrinolysis. Thromb Haemost 2017. [DOI: 10.1055/s-0037-1613959] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
SummaryThe effect of oral contraceptives (OC) on fibrinolytic parameters was investigated in a cycle-controlled cross-over study in which 28 non-OC using women were randomly prescribed either a representative of the so-called second (30 µg ethinylestradiol, 150 µg levonorgestrel) or third generation OC (30 µg ethinylestradiol, 150 µg desogestrel) and who switched OC after a two month wash out period. During the use of OC, the levels of tissue-type plasminogen activator (tPA) activity, plasminogen, plasmin-α2-antiplasmin complexes and D-dimer significantly increased (by 30 to 80%), while the levels of plasminogen activator inhibitor-1 (PAI-1) antigen, PAI-1 activity and tPA antigen significantly decreased (25 to 50%), suggesting an increase in endogenous fibrinolytic activity. These OC-induced changes were not different between the two contraceptive pills. TAFI (thrombin-activatable fibrinolysis inhibitor) levels increased on levonorgestrel, and even further increased on desogestrel. A clot lysis assay that probes both fibrinolytic activity and the efficacy of the coagulation system to generate thrombin necessary to down regulate fibrinolysis via TAFI showed no change of the clot lysis time during OC use. This finding suggests that the OC-induced increase in endogenous fibrinolytic activity is counteracted by an increased capacity of the coagulation system to down regulate fibrinolysis via TAFI. Indeed we observed that during OC use there was a significant increase of F1+2 generation during clot formation. When these assays were performed in the presence of an antibody against factor XI, we observed that the clot lysis time was significantly increased during OC use and that the increase in F1+2 generation during OC therapy was due to a factor XI-independent process, which was significantly higher on desogestrel than on levonorgestrel. These data indicate that the OC-induced inhibition of endogenous fibrinolysis takes place in a factor XI-independent way and is more pronounced on desogestrel than on levonorgestrel-containing OC.
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Meijers J, van den Ende A, van Enk A, Bouma B, Tans G, Rosing J, Prins M, Büller H, Middeldorp S. Effects on Coagulation of Levonorgestrel- and Desogestrel-containing Low Dose Oral Contraceptives: a Cross-over Study. Thromb Haemost 2017. [DOI: 10.1055/s-0037-1613958] [Citation(s) in RCA: 75] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
SummaryCombined oral contraceptives (OC) are known to increase the risk of venous thromboembolism. The aim of this randomized, cycle-controlled, cross-over study in 28 healthy volunteers was to assess potential differences between the effects of an OC containing 150 µg levonorgestrel (as representative of the so-called second generation OC) and an OC containing 150 µg desogestrel (as representative of the third generation OC) in combination with 30 µg ethinylestradiol on several coagulation factors and markers of thrombin formation. All participants used each OC for two cycles, and were switched to the other OC after a washout period of two menstrual cycles. The plasma concentrations of factors II, VII, X, and fibrinogen significantly increased during use of both the levonorgestrel- and desogestrel-containing OC’s. The plasma concentrations of factor VIII increased, and of factor V decreased, changes which only reached statistical significance during the use of the desogestrel-containing OC. During exposure to the desogestrel-containing OC, as compared with the levonorgestrel-containing OC, both factor VII and factor II showed a greater increase (FVII: 32% and 12% respectively; p <0.0001; FII: 16% and 12% respectively; p = 0.048), whereas factor V showed a greater decrease (–11% and –3% respectively; p = 0.010). Only one of the markers for ongoing coagulation (prothrombin fragment 1+2) showed a significant increase during OC use, whereas concentrations of thrombin-antithrombin complexes and soluble fibrin remained unchanged. For these markers, there was no difference between the tested OC’s. We conclude that there are differences between the effects of levonorgestrel and desogestrel-containing OC’s on some coagulation factors. Whether these changes provide a biological explanation for the reported differences in venous thromboembolic risk is as yet unclear. The real challenge now becomes to define a pattern of changes in the various systems which, if affected simultaneously, may tip the hemostatic balance towards a prethrombotic state and may lead to overt clinical venous thromboembolism.
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Tans G, Curvers J, Middeldorp S, Thomassen MC, Prins M, Bouma B, Büller H, Meijers J, Rosing J. A Randomized Cross-over Study on the Effects of Levonorgestrel- and Desogestrel-containing Oral Contraceptives on the Anticoagulant Pathways. Thromb Haemost 2017. [DOI: 10.1055/s-0037-1613960] [Citation(s) in RCA: 103] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
SummaryThe use of oral contraceptives (OC) causes disturbances of the procoagulant, anticoagulant and fibrinolytic pathways of blood coagulation which may contribute to the increased risk of venous thrombosis associated with OC therapy. Here we report the results of a cyclecontrolled randomized cross-over study, in which we determined the effects of so-called second and third generation OC’s on a number of anticoagulant parameters. In this study, 28 non-OC using women were randomly prescribed either a second generation (150 µg levonorgestrel/30 µg ethinylestradiol) or a third generation OC (150 µg desogestrel/30 µg ethinylestradiol) and who switched to the other OC after a two month wash out period. The anticoagulant parameters determined were: antithrombin (AT), α2-macroglobulin (α2-M), α1-antitrypsin, protein C inhibitor (PCI), protein C, total and free protein S and activated protein C sensitivity ratios (APC-sr) measured with two functional APC resistance tests which quantify the effect of APC on either the activated partial thromboplastin time (aPTT) or on the endogenous thrombin potential (ETP). During the use of desogestrel-containing OC the plasma levels of αc2-M, α1-antitrypsin, PCI and protein C significantly increased, whereas AT and protein S significantly decreased. Similar trends were observed with levonorgestrel-containing OC, although on this kind of OC the changes in AT, PCI and protein S (which was even slightly increased) did not reach significance. Compared with levonorgestrel, desogestrel-containing OC caused a significant decrease of total (p <0.005) as well as free protein S (p <0.0001) and more pronounced APC resistance in both the aPTT (p = 0.02) and ETPbased (p <0.0001) APC resistance tests. These observations indicate that the activity of the anticoagulant pathways in plasma from users of desogestrel-containing OC is more extensively impaired than in plasma from users of levonorgestrel-containing OC.
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Mosnier L, Meijers J, Bouma B. The Role of Protein S in the Activation of Thrombin Activatable Fibrinolysis Inhibitor (TAFI) and Regulation of Fibrinolysis. Thromb Haemost 2017. [DOI: 10.1055/s-0037-1616531] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
SummaryThrombin activatable fibrinolysis inhibitor (TAFI) is a carboxypeptidase B-like proenzyme that after activation by thrombin downregulates fibrinolysis. Thrombomodulin stimulates the activation of both TAFI and protein C whereas activated protein C inhibits the activation of TAFI by downregulation of thrombin formation, a process in which protein S acts as a cofactor. Here we determined the role of protein S in the activation of TAFI and regulation of fibrinolysis. Depletion of protein S from plasma or inhibition of protein S by specific antibodies resulted in an increased rate of TAFI activation and in an increased maximum of TAFIa activity generated. The effect on the rate of TAFI activation could be attributed to the APC-independent anticoagulant function of protein S whereas the effect on the maximum activity could be attributed to the APC cofactor function of protein S. Therefore it is concluded that protein S inhibits TAFI activation in two ways. On one hand, protein S functions as a cofactor for APC which results in a reduction of the maximum induced TAFI activity and on the other hand protein S inhibits the initial thrombin formation independently of APC which results in a decreased rate of TAFI activation. The effect of the APC-independent anticoagulant activity of protein S on the activation of TAFI provides a new mechanism for the regulation of fibrinolysis in the early stages of clot formation.
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Mosnier L, Elisen M, Meijers J, Bouma B. Protein C Inhibitor Regulates the Thrombin-Thrombomodulin Complex in the Up- and Down Regulation of TAFI Activation. Thromb Haemost 2017. [DOI: 10.1055/s-0037-1616533] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
SummaryThrombin Activatable Fibrinolysis Inhibitor (TAFI) is a carboxypeptidase B-like proenzyme that after activation by thrombin down regulates fibrinolysis. Thrombomodulin (TM) stimulates the activation of both TAFI and protein C whereas activated protein C (APC) inhibits the activation of TAFI by down regulating thrombin generation. Recently, protein C inhibitor (PCI) was identified as a potent inhibitor of thrombin bound to TM and it can thereby regulate the balance between TAFI activation, and inhibition of TAFI activation by APC. Both in a purified system and in plasma, activation of TAFI and protein C by IIa-TM could be inhibited by PCI. Previously we found in plasma that at low concentrations (~1 nM), TM predominantly stimulated the activation of TAFI whereas at higher concentrations of TM (~10 nM) the activation of protein C resulted in inhibition of the activation of TAFI. In agreement with this, PCI inhibited the activation of TAFI at 1 nM TM whereas at 10 nM TM PCI inhibited the activation of protein C resulting in an increase in the activation of TAFI. This suggests that PCI can up regulate TAFI activation by inhibiting the protein C activation. PCI may therefore be an important regulator in the balance between coagulation and fibrinolysis by differentially inhibiting the activation of TAFI and of protein C. The local TM concentration plays an important role in the outcome of this process.
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Mosnier L, Lisman T, Berg MVD, Nieuwenhuis K, Meijers J, Bouma B. The Defective Down Regulation of Fibrinolysis in Haemophilia A Can Be Restored by Increasing the TAFI Plasma Concentration. Thromb Haemost 2017. [DOI: 10.1055/s-0037-1616530] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
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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Abstract
IntroductionExposure of blood to negatively-charged surfaces, such as collagen, kaolin, or glass, results in the activation of the contact system of the intrinsic pathway of coagulation. Prekallikrein, factor XII, high molecular weight kininogen, and factor XI are the proteins involved in this contact reaction. The assembly of these components on a negatively-charged surface leads to the activation of factor XI, thereby propagating the intrinsic coagulation pathway. Simultaneously, several other reactions occur, such as the activation of factor VII and the initiation of the fibrinolytic system, kinin-forming pathway, and renin-angiotensin pathway.The first step in the contact phase is to bind factor XII to the negatively-charged surface, making it highly susceptible for proteolysis by kallikrein.1-3 Activated factor XII (α-factor XIIa) is formed in a process that may involve autoactivation.4-7 Prekallikrein is bound to high molecular weight kininogen in plasma. High molecular weight kininogen associates with a negatively-charged surface, thereby localizing prekallikrein to the surface. Limited proteolysis by α-factor XIIa converts prekallikrein to kallikrein. Kallikrein can dissociate from the surface and act on surface-bound factor XII at distant sites, thereby propagating the reciprocal cycle.7 Factor XI circulates plasma in a complex with high molcular weight kininogen. High molecular weight kininogen links factor XI to a negatively charged surface where it is activated by surface bound:α-factor XIIa. Although the in vivo, activating, negatively-charged surface is unknown, assembly and activation of the contact system on biological membranes of endothelial cells, platelets, neutrophils, and monocytes can take place, suggesting that these surfaces are the actual activating surfaces in vivo.8
The physiological significance of the contact system in blood coagulation remains unclear, however, because a deficiency of factor XII, prekallikrein, and high molecular weight kininogen does not result in a bleeding disorder. In contrast, patients deficient in factor XI, most common among Ashkenazi Jews, do suffer from variable bleeding abnormalities, especially from tissues with high local fibrinolytic activity (e.g., urinary tract, nose, oral cavity, tonsils).9,10 This suggested that there was an alternative route for the activation of factor XI, and recently, such a route was described.11,12 Thrombin was found to activate factor XI even in the absence of a negatively-charged surface,11-15 and factor XI was shown to play a role in the downregulation of fibrinolysis.16 In this article, the role of the contact system, with an emphasis on factor XI in the regulation of the fibrinolytic system, will be described.
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Boer K, Berckmans R, Meijers J, van der Post J, Sturk A, Van Bavel E, Nieuwland R, Van Wijk M. Enhanced Coagulation Activation in Preeclampsia: the Role of APC Resistance, Microparticles and Other Plasma Constituents. Thromb Haemost 2017. [DOI: 10.1055/s-0037-1613231] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
SummaryCoagulation activation in pregnancy is further enhanced in preeclampsia. We investigated whether this results from increased thrombin generation by the plasma itself or its cell-derived microparticles. Plasma samples were obtained from preeclamptic, normal pregnant and nonpregnant women (each n = 10). Prothrombin fragment 1+2 (F1+2) and thrombin-antithrombin complex (TAT) concentrations were increased in pregnancy and further increased in preeclampsia. In pregnancy and preeclampsia, increased activated protein C resistance occurred (APC sensitivity ratio: 3.3 ± 0.8 and 2.5 ± 0.8, both P < 0.001 vs. nonpregnant). In normal pregnant microparticle-free plasma the thrombin generation correlated with TAT (r = 0.84, P = 0.005) and APC resistance correlated with F1+2 (r = 0.68, P = 0.04). In preeclampsia thrombin generation by plasma was increased (P = 0.005), independent of APC resistance. Thrombin generation by microparticles was similar in all groups, although different coagulation activation pathways were utilized, indicating that circulating microparticles are not directly involved in coagulation activation in pregnancy and preeclampsia. In contrast, APC resistance can explain coagulation activation in pregnancy, while enhanced coagulation activation in preeclampsia results, in part, from an increased thrombin generating capacity of plasma independent of APC resistance.
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Meijers J, Bouma B, Mosnier L. Regulation of Fibrinolysis in Plasma by TAFI and Protein C Is Dependent on the Concentration of Thrombomodulin. Thromb Haemost 2017. [DOI: 10.1055/s-0037-1612655] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
SummaryThrombin activatable fibrinolysis inhibitor (TAFI) is a carboxypeptidase B-like proenzyme, that after activation down regulates fibrinolysis. TAFI is activated by thrombin in the presence of the cofactor thrombomodulin (TM). By stimulation of TAFI activation TM down regulates fibrinolysis, however TM is also a cofactor in the activation of protein C. Activated protein C (APC) can up regulate fibrinolysis by limiting the activation of TAFI via the attenuation of thrombin production. We studied these counteracting fibrinolytic properties of TM in plasma by measuring the activation of TAFI during tissue factor induced coagulation. TAFI activation was stimulated at low concentrations of TM but decreased at higher concentrations of TM. Similarly, the clot lysis times increased at low concentrations of TM but decreased at higher concentrations of TM. The reduction of TAFI activation at high TM concentrations was found to be dependent on a functional protein C pathway. The concentration of TM is therefore an important factor in the regulation of TAFI activation and in the regulation of fibrinolysis. High concentrations of TM result in up regulation of fibrinolysis, whereas low concentrations of TM have a down regulatory effect on fibrinolysis. These results suggest that fibrinolysis might be differentially regulated by TM in different parts of the body depending on the local TM concentration in the vasculature.
Abbreviations: TAFI, thrombin activatable fibrinolysis inhibitor; TAFIa, activated TAFI; CPI, carboxypeptidase inhibitor from potato tubers; tPA, tissue-type plasminogen activator; TM, thrombo-modulin; TM4-6, Thrombomodulin fragment containing EGF domains 4 to 6; HMEC, human microvascular endothelial cell.
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von dem Borne P, Meijers J, Bouma B. Factor XI and Protection of the Fibrin Clot against Lysis – a Role for the Intrinsic Pathway of Coagulation in Fibrinolysis. Thromb Haemost 2017. [DOI: 10.1055/s-0037-1615132] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
IntroducationBlood coagulation is an important mechanism that maintains the integrity of the vascular system to prevent blood loss after injury. The conceptions on the working mechanism of coagulation are based on the waterfall or cascade model, which was already proposed more than 30 years ago, independently by Davie and Ratnoff (1) and MacFarlane (2). Blood coagulation was viewed as a series of linked proteolytic reactions in which zymogens are converted into serine proteases, ultimately leading to the formation of thrombin, which converts soluble fibrinogen into insoluble fibrin. Coagulation was thought to proceed via two pathways, an extrinsic and an intrinsic pathway. Activation of the extrinsic pathway of coagulation occurs by the exposition of tissue factor at the site of injury (3) whereas the intrinsic system is activated after exposure of plasma to an activating surface. Although the in vivo activating surface is unknown, the contact system was believed to play a role in the initiation of the intrinsic pathway. This system consists of factor XII, prekallikrein, high molecular weight kininogen and factor XI. The physiological relevance of the contact system is unclear, since a deficiency of factor XII, prekallikrein or high molecular weight kininogen does not result in a bleeding disorder. In contrast, patients deficient in factor XI, most common among Ashkenazi Jews, do suffer from variable bleeding abnormalities especially from tissues with high local fibrinolytic activity (urinary tract, nose, oral cavity, tonsils) (4, 5). This suggested there was an alternative route for the activation of factor XI, and recently such a route was described (6, 7). Thrombin was found to activate factor XI, even in the absence of a negatively charged surface (6-11), and factor XI was shown to play a role in the protection of the fibrin clot against lysis (9). In plasma the possibility cannot be excluded that the activation of factor XI by thrombin takes place via an intermediary component. Recently, it was shown that meizothrombin was capable of activating factor XI (12).
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Oort E, Lisman T, Meijers J, Derksen R, de Groot P, Horbach D. β2-Glycoprotein I Is Proteolytically Cleaved In Vivo upon Activation of Fibrinolysis. Thromb Haemost 2017. [DOI: 10.1055/s-0037-1614424] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Summaryβ2-glycoprotein I (β2GPI) is a plasma glycoprotein with unknown physiological function(s). In in vitro experiments it has been demonstrated that β2GPI has both anticoagulant properties, such as the inhibition of factor X and prothrombin activation and procoagulant properties, such as the inhibition of the anticoagulant activity of activated protein C. Besides this, β2GPI bound to cardiolipin is recognized by anti-phospholipid antibodies (aPL).In this study we demonstrate that β2GPI is very sensitive for cleavage between Lys317 and Thr318 by plasmin, resulting in two immunologically different cleaved forms. In vitro experiments show that these plasmin cleaved forms of β2GPI bind to negatively charged phospho-lipids with much lower affinity compared to intact β2GPI. Similar to plasmin, trypsin and elastase can also induce this proteolytical cleavage in β2GPI, whereas thrombin and factor Xa do not cleave β2GPI. The in vivo occurrence of the proteolytical cleavage was demonstrated by the finding that in plasmas of patients with disseminated intravascular coagulation(DIC) and in plasmas of patients treated with streptokinase, significant amounts of cleaved β2GPI (up to 12 μg/ml) are present.During the development of DIC, the increase in levels of cleaved β2GPI is accompanied by a 70% decrease in the levels of intact β2GPI, whereas in streptokinase treated patients levels of intact β2GPI stay within the normal range.This study demonstrates for the first time that during in vivo activation of fibrinolysis β2GPI is cleaved, which results in the formation of a form of β2GPI with much lower affinity for negatively charged phospholipids. Plasmin is most likely responsible for this modification.
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van ’t Veer C, Meijers J, Bertina R, Wijnen MV, Bouma B. A Plasma Coagulation Assay for an Activated Protein C-independent Anticoagulant Activity of Protein S. Thromb Haemost 2017. [DOI: 10.1055/s-0037-1615391] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
SummaryTo study the physiological importance of the activated protein C (APC)-independent anticoagulant activity of protein S, we developed an assay specific for this activity. The ability of protein S to prolong the clotting time in an APC-independent way was expressed as the ratio of the clotting time in a plasma sample divided by the clotting time in the presence of a polyclonal antibody against human protein S (both after 1:1 dilution in protein S-C4BP deficient plasma). The mean protein S-dependent anticoagulant ratio (PSdAR) was 1.53 ± 0.18 in 34 healthy controls, and was significantly lower in 16 heterozygous protein S deficient patients (PSdAR = 1.15 ± 0.09). In plasmas from patients under oral anticoagulant therapy the mean PSdAR was within the range of the control population (1.50 ± 0.18). The mean total protein S antigen level in these plasmas was 58%, suggesting a higher specific APC-independent anticoagulant activity of protein S in these patients than in normals.This functional protein S assay can be used for the laboratory diagnosis of protein S deficiency, and to study the mechanism of the APC-independent anticoagulant activity in plasma.
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van Vuuren A, Girma M, Tiekstra M, Kwast L, Koster J, Rijneveld A, Elisen M, van der Poll T, Meijers J, Wagenaar G. Characterization of Transgenic Mice that Secrete Functional Human Protein C Inhibitor into the Circulation. Thromb Haemost 2017. [DOI: 10.1055/s-0037-1613763] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
SummaryProtein C inhibitor (PCI) is a heparin binding serine protease inhibitor in plasma, which exerts procoagulant activity by inhibiting thrombomodulinbound thrombin or activated protein C (APC). Since the role of PCI in vivo is largely unknown we generated genetically modified mice with expression of human PCI mRNA in hepatocytes only. Three transgenic lines have been characterized. Transgenic mice did not show gross developmental abnormalities. Two lines showed a pericentral and one line showed a periportal expression pattern of human PCI mRNA in the liver. Genetically modified mice secreted a functional transgenic protein into the circulation (3-5 µg/ml plasma in heterozygous mice and 10 µg/ml in homozygous mice), which inhibited human APC activity in the presence of heparin. Interestingly, transgenic mice in which human PCI was expressed periportally in the liver had the highest specific activity. Endogenous mouse PCI mRNA could only be detected in the male and female reproductive system, but not in the liver, indicating that endogenous PCI levels in the circulation are low or even absent in mice. These results demonstrate that the human PCI transgenic mice are a suitable model for studying the in vivo role of PCI in blood coagulation.
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van Montfoort M, Meijers J. Anticoagulation beyond direct thrombin and factor Xa inhibitors: indications for targeting the intrinsic pathway? Thromb Haemost 2017; 110:223-32. [DOI: 10.1160/th12-11-0803] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2012] [Accepted: 05/07/2013] [Indexed: 11/05/2022]
Abstract
SummaryAntithrombotic drugs like vitamin K antagonists and heparin have been the gold standard for the treatment and prevention of thromboembolic disease for many years. Unfortunately, there are several disadvantages of these antithrombotic drugs: they are accompanied by serious bleeding problems, it is necessary to monitor the therapeutic window, and there are various interactions with food and other drugs. This has led to the development of new oral anticoagulants, specifically inhibiting either thrombin or factor Xa. In terms of effectiveness, these drugs are comparable to the currently available anticoagulants; however, they are still associated with issues such as bleeding, reversal of the drug and complicated laboratory monitoring. Vitamin K antagonists, heparin, direct thrombin and factor Xa inhibitors have in common that they target key proteins of the haemostatic system. In an attempt to overcome these difficulties we investigated whether the intrinsic coagulation factors (VIII, IX, XI, XII, prekallikrein and high-molecular-weight kininogen) are superior targets for anticoagulation. We analysed epidemiological data concerning thrombosis and bleeding in patients deficient in one of the intrinsic pathway proteins. Furthermore, we discuss several thrombotic models in intrinsic coagulation factor-deficient animals. The combined results suggest that intrinsic coagulation factors could be suitable targets for anticoagulant drugs.
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Bakhtiari K, Dessing M, van ’t Veer C, Spek C, Tanck M, Meijers J, van der Poll T, van Zoelen M. Ethyl pyruvate exerts combined anti-inflammatory and anticoagulant effects on human monocytic cells. Thromb Haemost 2017. [DOI: 10.1160/th06-07-0393] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
SummarySepsis is characterized by a concurrent activation of inflammation and coagulation. Recently, recombinant human activated protein C was shown to decrease mortality in patients with severe sepsis presumably due to a combined anti-inflammatory and anticoagulant effect.These promising findings led to a search for other products that influence both the inflammatory and the procoagulant response to severe infection. Ethyl pyruvate (EP) was recently identified as an experimental anti-inflammatory agent during endotoxemia and sepsis. The aim of the present study was to investigate whether EP influences coagulation besides its anti-inflammatory effects. For this we investigated the effects of EP on the expression and function of tissue factor (TF), the principal initiator of coagulation activation in sepsis, in human monocytic (THP-1) cell cultures. EP dose-dependently inhibited the production of tumor necrosis factor (TNF)-α, macrophage inflammatory protein (MIP)-1α and MIP-1β by lipopolysaccharide (LPS)-stimulated THP-1 cells at mRNA and protein level, thereby confirming its anti-inflammatory properties in this in-vitro system.In addition, EP dose-dependently attenuated the increases in TF mRNA levels,TF-protein-surface expression and cell-surface-associated TF activity in LPS-stimulated THP-1 cells. These results demonstrate for the first time that EP is a compound with combined anti-inflammatory and anticoagulant effects.
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Serón M, Plug T, Arnoud Marquart J, Marx P, Herwald H, de Groot P, Meijers J. Binding characteristics of thrombin-activatable fibrinolysis inhibitor to streptococcal surface collagen-like proteins A and B. Thromb Haemost 2017; 106:609-16. [DOI: 10.1160/th11-03-0204] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2011] [Accepted: 06/22/2011] [Indexed: 11/05/2022]
Abstract
SummaryStreptococcus pyogenes is the causative agent in a wide range of diseases in humans. Thrombin-activatable fibrinolysis inhibitor (TAFI) binds to collagen-like proteins SclA and SclB at the surface of S. pyogenes. Activation of TAFI at this surface redirects inflammation from a transient to chronic state by modulation of the kallikrein/kinin system. We investigated TAFI binding characteristics to SclA/SclB. Thirty-four overlapping TAFI peptides of ∼20 amino acids were generated. Two of these peptides (P18: residues G205-S221, and P19: R214-D232) specifically bound to SclA/SclB with high affinity, and competed in a dose-dependent manner with TAFI binding to SclA/SclB. In another series of experiments, the binding properties of activated TAFI (TAFIa) to SclA/SclB were studied with a quadruple TAFI mutant (TAFI-IIYQ) that after activation is a 70-fold more stable enzyme than wild-type TAFIa. TAFI and TAFI-IIYQ bound to the bacterial proteins with similar affinities. The rate of dissociation was different between the proenzyme (both TAFI and TAFI-IIYQ) and the stable enzyme TAFIa-IIYQ. TAFIa-IIYQ bound to SclA/ SclB, but dissociated faster than TAFI-IIYQ. In conclusion, the bacterial proteins SclA and SclB bind to a TAFI fragment encompassing residues G205-D232. Binding of TAFI to the bacteria may allow activation of TAFI, whereafter the enzyme easily dissociates.
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Verkleij C, van Zaane B, Squizzato A, Brandjes D, Büller H, Meijers J, Gerdes V, Stuijver D. Thrombin-activatable fibrinolysis inhibitor in hypothyroidism and hyperthyroxinaemia. Thromb Haemost 2017. [DOI: 10.1160/th12-07-0525] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
SummaryEndocrine disorders affect both the coagulation and fibrinolytic systems, and have been associated with the development of cardiovascular diseases. Thrombin-activatable fibrinolysis inhibitor (TAFI) is a link between coagulation and the fibrinolytic system. The aim of this study was to determine the effect of thyroid hormone excess and deficiency on TAFI levels and function. The effect of hyperthyroxinemia on TAFI was studied in healthy volunteers who were randomised to receive levothyroxine or no medication for 14 days in a crossover design. The effect of hypothyroidism on TAFI was studied in a multicentre observational cohort study. Blood was drawn before treatment of patients with newly diagnosed hypothyroidism and when euthyroidism was achieved. Plasma clot-lysis times, activated TAFI (TAFIa)-dependent prolongation of clot-lysis and TAFI levels were measured. Thyroid hormone excess resulted in a hypofibrinolytic condition and in an enhanced TAFIa-dependent prolongation of clot lysis. A trend towards decreased plasma TAFI levels was observed in healthy volunteers who used levothyroxine. Hypothyroidism resulted in hyperfibrinolysis and a reduced TAFIa-dependent prolongation of clot lysis. In conclusion, alterations of TAFIa-dependent prolongation of clot lysis in patients with thyroid disorders may cause an impaired haemostatic balance. The disturbed haemostatic balance in patients with hyperthyroidism might make them prone to thrombosis, while the risk for bleeding may increase in patients with hypothyroidism.
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Meijers J, Maude R, Limmathurotsakul D, Day N, Peacock S, Poll T, Wiersinga W, Koh G. Diabetes does not influence activation of coagulation, fibrinolysis or anticoagulant pathways in Gram-negative sepsis (melioidosis). Thromb Haemost 2017; 106:1139-48. [DOI: 10.1160/th11-07-0504] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2011] [Accepted: 09/16/2011] [Indexed: 12/24/2022]
Abstract
SummaryDiabetes is associated with a disturbance of the haemostatic balance and is an important risk factor for sepsis, but the influence of diabetes on the pathogenesis of sepsis remains unclear. Melioidosis (Burkholderia pseudomallei infection) is a common cause of community-acquired sepsis in Southeast Asia and northern Australia. We sought to investigate the impact of pre-existing diabetes on the coagulation and fibrinolytic systems during sepsis caused by B. pseudomallei. We recruited a cohort of 44 patients (34 with diabetes and 10 without diabetes) with culture-proven melioidosis. Diabetes was defined as a pre-admission diagnosis of diabetes or an HbA1c>7.8% at enrolment. Thirty healthy blood donors and 52 otherwise healthy diabetes patients served as controls. Citrated plasma was collected from all subjects; additionally in melioidosis patients follow-up specimens were collected seven and ≥28 days after enrolment where possible. Relative to uninfected healthy controls, diabetes per se (i.e. in the absence of infection) was Characterised by a procoagulant effect. Melioidosis was associated with activation of coagulation (thrombin-antithrombin complexes (TAT), prothrombin fragment F1+2 and fibrinogen concentrations were elevated; PT and PTT prolonged), suppression of anti-coagulation (antithrombin, protein C, total and free protein S levels were depressed) and abnormalities of fibrinolysis (D-dimer and plasmin-antiplasmin complex [PAP] were elevated). Remarkably, none of these haemostatic alterations were influenced by pre-existing diabetes. In conclusion, although diabetes is associated with multiple abnormalities of coagulation, anticoagulation and fibrinolysis, these changes are not detectable when superimposed on the background of larger abnormalities attributable to B. pseudomallei sepsis.
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Ağar Ç, de Groot P, Marquart JA, Meijers J. Evolutionary conservation of the lipopolysaccharide binding site of β2-glycoprotein I. Thromb Haemost 2017; 106:1069-75. [DOI: 10.1160/th11-05-0333] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2011] [Accepted: 08/01/2011] [Indexed: 11/05/2022]
Abstract
Summaryβ2-Glycoprotein I (β2GPI) is a highly abundant plasma protein and the major antigen for autoantibodies in the antiphospholipid syndrome. Recently, we have described a novel function of β2GPI as scavenger of lipopolysaccharide (LPS). With this in mind we investigated the conservation of β2GPI in vertebrates and set out to identify the binding site of LPS within β2GPI. The genome sequences of 42 species were surveyed. Surface plasmon resonance (SPR) was performed with peptides to characterise the binding site of β2GPI for LPS. β2GPI could be identified in most tested vertebrates with a high overall amino acid homology of 80% or more in mammals. SPR revealed that a synthesised peptide (LAFWKTDA) from domain V of β2GPI was able to compete for binding of β2GPI to LPS. The AFWKTDA sequence was completely conserved in all mammals. The peptide containing the LPS binding site attenuated the inhibition by β2GPI in a cellular model of LPS-induced tissue factor expression. Other important sites, such as the binding site for anionic phospholipids and the antiphospholipid antibody binding epitope, were also preserved. β2GPI is highly conserved across the animal kingdom, which suggests that the function of β2GPI may be more important than anticipated.
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Schreijer A, Cannegieter S, Caramella M, Meijers J, Krediet R, Simons R, Rosendaal F. Fluid loss does not explain coagulation activation during air travel. Thromb Haemost 2017; 99:1053-9. [DOI: 10.1160/th07-11-0681] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
SummaryThe mechanism of air travel-related venous thrombosis is unclear. Although immobility plays a pivotal role, other factors such as fluid loss may contribute. We investigated whether fluid loss occurred more in individuals with coagulation activation after air travel than in subjects without. As a secondary aim, we investigated whether fluid loss per se occurred during air travel. In this crossover study, 71 healthy volunteers were exposed to eight hours of air travel, eight hours immobilization in a cinema, and a daily-life control situation. Markers of fluid loss (haematocrit, serum osmolality and albumin) and of coagulation activation were measured before and after each exposure. The study included ll volunteers with and 55 volunteers without coagulation activation during the flight. The change in parameters of fluid loss was not different in volunteers with an activated clotting system from those without (difference between groups in haematocrit: −0.6%, 95% confidence interval [CI]: −1.9 to 0.6). On a group level, mean haematocrit values decreased during all three exposures. However, in some individuals it increased, which occurred in more participants during the flight (34%; 95% CI 22 to 46) than during the daily-life situation (l9%; 95% CI 10 to 28). These findings do not support the hypothesis that fluid loss contributes to thrombus formation during air travel.
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Wichers I, Meijers J, Büller H, Reitsma P, Middeldorp S, Tanck M. Quantitative trait locus for protein C in a family with thrombophilia. Thromb Haemost 2017; 105:199-201. [DOI: 10.1160/th10-06-0383] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2010] [Accepted: 09/25/2010] [Indexed: 11/05/2022]
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Pennings M, de Groot P, Meijers J, Huisman A, Derksen R, Urbanus R. Optimisation of lupus anticoagulant tests: should test samples always be mixed with normal plasma? Thromb Haemost 2017; 112:736-42. [DOI: 10.1160/th14-02-0122] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Accepted: 05/08/2014] [Indexed: 11/05/2022]
Abstract
SummaryCoagulation factor deficiencies are thought to interfere with the detection of the phospholipid-dependent coagulation inhibitor known as lupus anticoagulant (LA). Treatment with vitamin K antagonists (VKA) in particular, is thought to preclude accurate LA assessment. For this reason, the procedure to detect LA includes a mixing test, in which coagulation factor deficiencies are corrected by mixing samples with an equal volume of normal plasma. Despite these mixing tests, interpretation of LA test results is considered difficult in patients receiving high intensity VKA treatment. As a result, VKA treatment is often temporarily discontinued to allow LA assessment. However, whether coagulation factor deficiencies influence LA test results is unclear. We found that neither deficiency of a single coagulation factor, nor a functional coagulation factor deficiency due to high intensity VKA treatment, resulted in false positive dRVVT- or APTT-based (silica clotting time; SCT) LA test results. LA was readily detected in unmixed samples from VKA-treated LA-positive patients with both dRVVT and SCT reagents. VKA treatment caused an underestimation of the strength of the LA with SCT reagents, but did not lead to misclassification of LA status. Although mixing with normal plasma during both screen and confirm tests allowed more accurate assessment of the strength of the LA with SCT reagents in samples with an international normalised >2.5, the mixing procedure itself lead to misclassification of LA in weakly positive samples from patients not treated with VKA. Based on these findings, we conclude that mixing studies are not necessary during LA-assessment.
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Abstract
BACKGROUND A growing body of neuropsychological and neurobiological research shows a relationship between functioning of the prefrontal cortex and criminal and violent behaviour. The prefrontal cortex is crucial for executive functions such as inhibition, attention, working memory, set-shifting and planning. A deficit in these functions - a prefrontal deficit - may result in antisocial, impulsive or even aggressive behaviour. While several meta-analyses show large effect sizes for the relationship between a prefrontal deficit, executive dysfunction and criminality, there are few studies investigating differences in executive functions between violent and non-violent offenders. Considering the relevance of identifying risk factors for violent offending, the current study explores whether a distinction between violent and non-violent offenders can be made using an extensive neuropsychological test battery. METHOD Male remand prisoners (N = 130) in Penitentiary Institution Amsterdam Over-Amstel were administered an extensive neuropsychological test battery (Cambridge Automated Neuropsychological Test Battery; CANTAB) measuring response inhibition, planning, attention, set-shifting, working memory and impulsivity/reward sensitivity. RESULTS Violent offenders performed significantly worse on the stop-signal task (partial correlation r = 0.205, p = 0.024), a task measuring response inhibition. No further differences were found between violent and non-violent offenders. Explorative analyses revealed a significant relationship between recidivism and planning (partial correlation r = -0.209, p = 0.016). CONCLUSION Violent offenders show worse response inhibition compared to non-violent offenders, suggesting a more pronounced prefrontal deficit in violent offenders than in non-violent offenders.
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Affiliation(s)
- J Meijers
- Department of Clinical, Neuro- and Developmental Psychology,Vrije Universiteit Amsterdam,Amsterdam,The Netherlands
| | - J M Harte
- Department of Criminal Law and Criminology,Vrije Universiteit Amsterdam,Amsterdam,The Netherlands
| | - G Meynen
- Department of Philosophy,Faculty of Humanities,Vrije Universiteit Amsterdam,Amsterdam,The Netherlands
| | - P Cuijpers
- Department of Clinical, Neuro- and Developmental Psychology,Vrije Universiteit Amsterdam,Amsterdam,The Netherlands
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Elbers LPB, Moran C, Gerdes VE, van Zaane B, Meijers J, Endert E, Lyons G, Chatterjee VK, Bisschop PH, Fliers E. The Hypercoagulable state in Hyperthyroidism is mediated via the Thyroid Hormone β Receptor pathway. Eur J Endocrinol 2016; 174:EJE-15-1249. [PMID: 26961801 PMCID: PMC7613030 DOI: 10.1530/eje-15-1249] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
OBJECTIVE Hyperthyroidism is associated with a hypercoagulable state, but the underlying mechanism is unknown. Patients with resistance to thyroid hormone (RTH) due to defective thyroid hormone receptor β (TRβ) exhibit elevated circulating thyroid hormones (TH) with refractoriness to TH action in TRβ-expressing tissues. We tested the hypothesis that the hypercoagulable state in hyperthyroidism is mediated via the TRβ. DESIGN We conducted a cross-sectional study from November 2013 to January 2015 in 3 hospitals in the Netherlands and the United Kingdom. METHODS Patients with RTH due to defective TRβ (n=18), patients with hyperthyroidism (n=16) and euthyroid subjects (n=18) were included. TH concentrations and markers of coagulation and fibrinolysis were measured. Data are expressed as median [interquartile range]. RESULTS Free thyroxine (FT4) levels were slightly higher in hyperthyroid patients than in RTH patients (53.9 [30.5-70.0] and 34.9 [28.4-42.2]pmol/l, respectively, P=0.042). Both groups had raised FT4 levels compared to euthyroid subjects (14.0 [13.0-15.8] pmol/l, P≤0.001). Levels of von Willebrand factor (VWF), factor (F) VIII, fibrinogen, and D-dimer were significantly higher in hyperthyroid patients than in RTH patients (VWF 231 [195-296] vs. 111 [82-140]%, FVIII 215 [192-228] vs. 145 [97-158]%, fibrinogen 3.6 [3.0-4.4] vs. 2.8 [2.5-3.2]g/L, D-dimer 0.41 [0.31-0.88] vs. 0.20 [0.17-0.26]mg/L, respectively, P≤0.001), while there were no differences between RTH patients and euthyroid controls. CONCLUSIONS Parameters of coagulation and fibrinolysis were elevated in hyperthyroid patients compared to patients with RTH due to defective TRβ, whereas these parameters were not different between euthyroid controls and RTH patients, despite elevated FT4 concentrations in RTH patients. This indicates that the procoagulant effects observed in hyperthyroidism are mediated via the TRβ.
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Affiliation(s)
- Laura P B Elbers
- L Elbers, Internal Medicine, Medical Center Slotervaart, Amsterdam, Netherlands
| | - Carla Moran
- C Moran, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, University of Cambridge Metabolic Research Laboratories, Cambridge, United Kingdom of Great Britain and Northern Ireland
| | - Victor Ea Gerdes
- V Gerdes, Internal Medicine, Medical Center Slotervaart, Amsterdam, Netherlands
| | - Bregje van Zaane
- B van Zaane, Internal Medicine, Medical Center Slotervaart, Amsterdam, Netherlands
| | - Joost Meijers
- J Meijers, Experimental Vascular Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands
| | - Erik Endert
- E Endert, Laboratory of Endocrinology and Radiochemistry, Department of Clinical Chemistry, Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands
| | - Greta Lyons
- G Lyons, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, University of Cambridge Metabolic Research Laboratories, Cambridge, United Kingdom of Great Britain and Northern Ireland
| | - V Krishna Chatterjee
- V Chatterjee, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, University of Cambridge Metabolic Research Laboratories, Cambridge, United Kingdom of Great Britain and Northern Ireland
| | - Peter H Bisschop
- P Bisschop, Endocrinology and Metabolism, Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands
| | - Eric Fliers
- E Fliers, Endocrinology and Metabolism, Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands
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Teunissen PF, Kamp O, Kamphuisen PW, Meijers J, Tijssen R, Eerenberg ES, Jansen MF, Niessen HW, van Royen N. TCT-236 The role of ADAMTS13 in acute myocardial infarction: cause or consequence? J Am Coll Cardiol 2015. [DOI: 10.1016/j.jacc.2015.08.919] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Vergouwen M, Knaup V, Aronica E, Rinkel G, Meijers J. Abstract T P395: Complement Activation in Delayed Cerebral Ischemia After Aneurysmal Subarachnoid Hemorrhage - An Autopsy Study. Stroke 2015. [DOI: 10.1161/str.46.suppl_1.tp395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background:
The pathogenesis of delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage (aSAH) remains unclear. It has been hypothesized that an inflammatory response in the subarachnoid space and microthrombosis contribute to DCI. Previous studies showed that plasma levels of complement factors are associated with DCI and functional outcome after aSAH. We performed an autopsy study to investigate the relationship between complement activation, microthrombosis and DCI.
Methods:
In autopsy material from 7 patients who died from DCI, we isolated 9 areas of cerebral infarction and 15 areas without infarction. From autopsy material of 5 controls (myocardial infarction: n=3; heart failure: n=1; pulmonary embolism: n=1) we isolated 15 corresponding areas. We performed immunohistochemistry to investigate the presence of C1q, C3c, and fibrin(ogen) (which is strongly correlated with microthrombosis). Optical density measurements were used for quantitative assessments. Optical density values were compared between areas with infarction, without infarction, and controls, and analyzed with a Mann-Whitney U test. Spearman correlation tests were performed to investigate the relationships of C1q and C3c with fibrin(ogen).
Results:
Optical density values of C1q, C3c, and fibrin(ogen) were higher in areas of infarction than in areas without infarction or controls (Table 1, p<0.001 for all comparisons). Correlations were found between C1q and fibrin(ogen) (r=0.73, p<0.001) and C3c with fibrin(ogen) (r=0.74, p<0.001).
Conclusion:
Our results show that areas of cerebral infarction in patients with aSAH have more complement activation and microthrombosis than areas without infarction or control brains. A strong correlation was found between complement activation and microthrombosis. Future studies are needed to investigate if drugs targeting complement activation decrease the risk of DCI and improve outcome after aSAH.
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Cheung W, Barco S, Coppens M, Hutten B, Meijers J, Middeldorp S. IN VIVO REVERSAL OF THE ANTICOAGULANT EFFECT OF RIVAROXABAN WITH 4-FACTOR PROTHROMBIN COMPLEX CONCENTRATE. J Am Coll Cardiol 2014. [DOI: 10.1016/s0735-1097(14)60334-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Straat M, Muller M, Meijers J, Schultz M, Juffermans N. Effect of a fixed dose of fresh frozen plasma on systemic inflammation and endothelial damage in nonbleeding critically ill patients. Crit Care 2014. [PMCID: PMC4068319 DOI: 10.1186/cc13306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Reuther S, van Nie N, Meijers J, Halfens R, Bartholomeyczik S. [Malnutrition and dementia in the elderly in German nursing homes. Results of a prevalence survey from the years 2008 and 2009]. Z Gerontol Geriatr 2013; 46:260-7. [PMID: 23283395 DOI: 10.1007/s00391-012-0346-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND AND OBJECTIVE Dementia is one of most challenging problems for the care of older people in Germany. Although malnutrition in nursing homes is also associated with dementia, few systematic studies have described health care structures in German nursing homes for people with dementia and their individual nutritional status. Therefore, the aim of this study was to determine dementia-specific differences concerning the nutrition situation for the elderly in German nursing homes. METHODS A cross-sectional multicenter study was performed using a standardized multilevel instrument (observation, questionnaire) developed at the University of Maastricht. Variables are indicators for malnutrition and its risks, quality indicators, care dependency and types of interventions. RESULTS In the 2008 and 2009 surveys, 53% of 4,777 participants (77.9% women, 22.1% men, mean age 82 years) were identified (based on care documentation) as having dementia. More than one third of this population (n = 759, 85.1% women, 14.1% men, mean age 85 years) was probably malnourished; thus, the prevalence rate in the group of people with dementia was 10% higher compared to the group without dementia. People with dementia showed a higher risk in all relevant risk indicators (weight history, body mass index, and food intake) for malnutrition compared to those without dementia. Furthermore, people with dementia had higher care dependency rates and required more assistance for eating and drinking. CONCLUSION The study results confirm the relationship between malnutrition and dementia. The use of standardized nutrition screening tools is not common practice in German nursing homes yet. However, the results suggest that with an increasing risk for malnutrition combined with dementia the proportion of nursing interventions also increases, which means that nurses must react adequately. Nevertheless, the interventions concerning malnutrition should be improved especially with respect to preventive measurements.
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Affiliation(s)
- S Reuther
- Deutsches Zentrum für Neurodegenerative Erkrankungen e.V. (DZNE), Standort Witten, Stockumer Str. 12, 58453, Witten, Deutschland.
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Meijers J, Eikenboom J. Special Issue: State of the Art 2013. Preface. J Thromb Haemost 2013; 11 Suppl 1:1. [PMID: 23809105 DOI: 10.1111/jth.12251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Affiliation(s)
- Y. Amir
- Caphri Department of Health Care and Nursing Science, Maastricht University, The Netherlands
- Riau University, Indonesia
| | - J. Meijers
- Caphri Department of Health Care and Nursing Science, Maastricht University, The Netherlands
| | - R. Halfens
- Caphri Department of Health Care and Nursing Science, Maastricht University, The Netherlands
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Bartholomeyczik S, Reuther S, Luft L, Nie NV, Meijers J, Schols J, Halfens R. Prävalenz von Mangelernährung, Maßnahmen und Qualitätsindikatoren in deutschen Altenpflegeheimen - erste Ergebnisse einer landesweiten Pilotstudie. Gesundheitswesen 2010; 72:868-74. [DOI: 10.1055/s-0029-1246150] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Marx P, Verkleij C, Seron M, Meijers J. Recent Developments in Thrombin-Activatable Fibrinolysis Inhibitor Research. Mini Rev Med Chem 2009; 9:1165-73. [DOI: 10.2174/138955709789055216] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2009] [Accepted: 05/15/2009] [Indexed: 11/22/2022]
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Tannen A, Schütz T, Dassen T, van Nie-Visser N, Meijers J, Halfens R. Mangelernährung in deutschen Pflegeheimen und Krankenhäusern - Pflegebedarf und pflegerische Versorgung. Aktuel Ernahrungsmed 2008. [DOI: 10.1055/s-2008-1067454] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Marx P, Lisman T, Adelmeijer J, Marquart J, Meijers J. ID: 199 Binding of TAFI to collagen: a role for TAFI in the regulation of platelet adhesion? J Thromb Haemost 2006. [DOI: 10.1111/j.1538-7836.2006.00199.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Hillmayer K, Brouwers E, Marx P, Meijers J, Declerck P, Gils A. ID: 189 Generation and characterization of monoclonal antibodies directed towards rat TAFI. J Thromb Haemost 2006. [DOI: 10.1111/j.1538-7836.2006.00189.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Abstract
Disseminated intravascular coagulation (DIC) is a syndrome characterized by systemic intravascular activation of coagulation, leading to widespread deposition of fibrin in the circulation. In recent years, the pathogenetic pathways leading to DIC have been largely identified, which could result in more precise diagnostic tests for this disorder. However, the clinical and laboratory diagnosis of DIC may remain difficult, since routinely available tests do not specifically assess ongoing thrombin generation. Molecular markers for activation of coagulation and fibrinogen to fibrin conversion are highly sensitive but also disappointedly aspecific for the diagnosis of DIC. Moreover, these tests are often not available in most settings for daily clinical care. A combination of widely available tests, however, may be helpful in making the diagnosis of DIC, according to a recently developed algorithm.
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Affiliation(s)
- Marcel Levi
- Department of Vascular Medicine and Internal Medicine, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands.
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Dörffler-Melly J, de Jonge E, Pont AC, Meijers J, Vroom MB, Büller HR, Levi M. Bioavailability of subcutaneous low-molecular-weight heparin to patients on vasopressors. Lancet 2002; 359:849-50. [PMID: 11897286 DOI: 10.1016/s0140-6736(02)07920-5] [Citation(s) in RCA: 142] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Venous thromboembolism is a frequent complication in patients admitted to intensive care units (ICU), despite prophylactic treatment with subcutaneous low-molecular-weight (LMW) heparin. We postulated that poor efficacy of subcutaneous heparin might be due to administration of vasopressors, which could cause impaired peripheral circulation and inadequate systemic bioavailability of the anticoagulant. We compared concentrations of factor Xa activity in three groups of 15 patients: individuals in ICU who had and had not received vasopressors, and general surgery patients. Those who received vasopressors had lower plasma concentrations of factor-Xa activity than patients in ICU not on vasopressors and postoperative controls. Patients in ICU who take vasopressors could need higher doses of LMW heparin, or a different mode of administration of the drug, to attain adequate thrombosis prophylaxis.
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Mosnier L, Meijers J, Griffin J, Bouma B. Factor XI Dependent and Independent Activation of Thrombin Activatable Fibrinolysis Inhibitor (TAFI) in Plasma Associated with Clot Formation. Thromb Haemost 1999. [DOI: 10.1055/s-0037-1614902] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
SummaryThrombin Activatable Fibrinolysis Inhibitor (TAFI) also known as plasma procarboxypeptidase B is activated by relatively high concentrations of thrombin in a reaction stimulated by thrombomodulin. In plasma an intact factor XI-dependent feed back loop via the intrinsic pathway is necessary to generate sufficient thrombin for TAFI activation. This thrombin generation takes place after clot formation with consequent down-regulation of fibrinolysis. We developed a specific and sensitive assay for activated TAFI (TAFIa) and studied its factor XI-dependent generation during clot formation. In the absence of thrombomodulin, addition of 20 nM thrombin to normal plasma generated 5-10% of the amount of TAFIa generated by 20 nM thrombin in the presence of 8 nM thrombomodulin. Minimal activation of TAFI was detected in factor II deficient plasma when clotting was initiated by 20 nM thrombin. Addition of 320-640 nM of thrombin to factor II deficient plasma resulted in the same amount of TAFIa as in normal plasma, suggesting that ~50% of factor II has to be converted to thrombin for extensive activation of TAFI. A Mab that neutralizes activated factor XII had no effect on TAFI activation indicating that an intact contact system is not necessary for the activation of TAFI. The dependency of TAFI activation of factor XI was tested using a Mab that neutralizes activated factor XI. When plasmas from 13 healthy individuals were tested, this Mab reduced TAFI activation by 65% (range 35-89%). Our results indicate that activation of TAFI in serum after clot formation can be quantitated and that it takes place in both factor XI-dependent and factor XI-independent mechanisms.
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Cleophas TJ, Kauw FH, Bijl C, Meijers J, Stapper G. Effects of beta adrenergic receptor agonists and antagonists in diabetics with symptoms of postural hypotension: a double-blind, placebo-controlled study. Angiology 1986; 37:855-62. [PMID: 2878632 DOI: 10.1177/000331978603701110] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Eleven patients with hyperadrenergic diabetic postural hypotension and vagal neuropathy were treated in a double-blind, placebo-controlled study with different beta-agonists and antagonists. A single dose of the beta 2-agonist terbutaline (5 mg) and the beta 1 + 2-agonist orciprenaline (10 mg) did not reduce the fall in systolic pressure on standing up, despite a significant increase in both supine and standing heart rates. The beta 1-antagonist with intrinsic sympathicomimetic activity (ISA) acebutolol (200 mg) and the beta 1-antagonist metoprolol (50 mg) did not influence the fall in systolic pressure either, despite a significant decrease in supine and standing heart rates and disappearance of increase in heart rate on standing up. Only the beta 1 + 2-antagonist propranolol and the beta 1 + 2-antagonist with ISA pindolol (5 mg) could significantly reduce or practically abolish the fall in systolic and diastolic pressure on standing up. This was accompanied by a slight decrease of heart rates and disappearance of difference between supine and standing heart rates, as seen with the other beta-antagonists. Thus, only beta 2-blockade reduced or abolished the fall in systolic pressure on standing up in our patients. These data were confirmed by a three-week crossover trial in 10 of these patients.
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Lugtenberg B, Meijers J, Peters R, van der Hoek P, van Alphen L. Electrophoretic resolution of the "major outer membrane protein" of Escherichia coli K12 into four bands. FEBS Lett 1975; 58:254-8. [PMID: 773686 DOI: 10.1016/0014-5793(75)80272-9] [Citation(s) in RCA: 1265] [Impact Index Per Article: 25.8] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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