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Prisco D, Canfora M, Mazzetti M, Mattioli I, Bettiol A. Factor XI Inhibitors: perspectives in primary and secondary prevention of ischemic stroke. Intern Emerg Med 2024:10.1007/s11739-024-03611-w. [PMID: 38743127 DOI: 10.1007/s11739-024-03611-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Accepted: 04/09/2024] [Indexed: 05/16/2024]
Abstract
Stroke is one of the most common causes of mortality and disability worldwide. Antithrombotic therapy represents the mainstay in primary and secondary prevention, both in cardioembolic and non-cardioembolic stroke. Particularly, direct oral anticoagulants play a crucial role in atrial fibrillation, the most common cause of cardioembolic stroke, whereas single or dual antiplatelet therapy is preferred in non-cardioembolic stroke. However, the limitations related to the residual risk of cardioembolic or cerebrovascular events, and the risk of major bleeding, still represent unmet medical needs. To overcome them, new drugs inhibiting Factor XI (FXI) and Factor XII have been proposed, with a selective inhibition of contact pathway of coagulation, delineating a new anticoagulant approach. This review provides a summary of the currently available evidence and future perspectives on FXI inhibitors, that can represent an additional therapeutic option in the primary and secondary prevention of cardioembolic and non-cardioembolic ischemic stroke, also in challenging therapeutic contexts.
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Affiliation(s)
- Domenico Prisco
- Department of Experimental and Clinical Medicine, University of Florence, Viale L.Go Giovanni Brambilla, 3, 50134, Florence, Italy
- Internal Interdisciplinary Medicine Unit, Careggi University Hospital, Florence, Italy
| | - Maria Canfora
- Department of Experimental and Clinical Medicine, University of Florence, Viale L.Go Giovanni Brambilla, 3, 50134, Florence, Italy.
| | - Matteo Mazzetti
- Internal Interdisciplinary Medicine Unit, Careggi University Hospital, Florence, Italy
| | - Irene Mattioli
- Department of Experimental and Clinical Medicine, University of Florence, Viale L.Go Giovanni Brambilla, 3, 50134, Florence, Italy
| | - Alessandra Bettiol
- Department of Experimental and Clinical Medicine, University of Florence, Viale L.Go Giovanni Brambilla, 3, 50134, Florence, Italy
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Gailani D, Gruber A. Targeting factor XI and factor XIa to prevent thrombosis. Blood 2024; 143:1465-1475. [PMID: 38142404 PMCID: PMC11033593 DOI: 10.1182/blood.2023020722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 11/22/2023] [Accepted: 12/07/2023] [Indexed: 12/26/2023] Open
Abstract
ABSTRACT Direct oral anticoagulants (DOACs) that inhibit the coagulation proteases thrombin or factor Xa (FXa) have replaced warfarin and other vitamin K antagonists (VKAs) for most indications requiring long-term anticoagulation. In many clinical situations, DOACs are as effective as VKAs, cause less bleeding, and do not require laboratory monitoring. However, because DOACs target proteases that are required for hemostasis, their use increases the risk of serious bleeding. Concerns over therapy-related bleeding undoubtedly contribute to undertreatment of many patients who would benefit from anticoagulation therapy. There is considerable interest in the plasma zymogen factor XI (FXI) and its protease form factor XIa (FXIa) as drug targets for treating and preventing thrombosis. Laboratory and epidemiologic studies support the conclusion that FXI contributes to venous and arterial thrombosis. Based on 70 years of clinical observations of patients lacking FXI, it is anticipated that drugs targeting this protein will cause less severe bleeding than warfarin or DOACs. In phase 2 studies, drugs that inhibit FXI or FXIa prevent venous thromboembolism after total knee arthroplasty as well as, or better than, low molecular weight heparin. Patients with heart disease on FXI or FXIa inhibitors experienced less bleeding than patients taking DOACs. Based on these early results, phase 3 trials have been initiated that compare drugs targeting FXI and FXIa to standard treatments or placebo. Here, we review the contributions of FXI to normal and abnormal coagulation and discuss results from preclinical, nonclinical, and clinical studies of FXI and FXIa inhibitors.
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Affiliation(s)
- David Gailani
- The Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN
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3
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Mohammed BM, Sun MF, Cheng Q, Litvak M, McCrae KR, Emsley J, McCarty OJT, Gailani D. High molecular weight kininogen interactions with the homologs prekallikrein and factor XI: importance to surface-induced coagulation. J Thromb Haemost 2024; 22:225-237. [PMID: 37813198 PMCID: PMC10841474 DOI: 10.1016/j.jtha.2023.09.027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 09/22/2023] [Accepted: 09/27/2023] [Indexed: 10/11/2023]
Abstract
BACKGROUND In plasma, high molecular weight kininogen (HK) is either free or bound to prekallikrein (PK) or factor (F) XI (FXI). During contact activation, HK is thought to anchor PK and FXI to surfaces, facilitating their conversion to the proteases plasma kallikrein and FXIa. Mice lacking HK have normal hemostasis but are resistant to injury-induced arterial thrombosis. OBJECTIVES To identify amino acids on the HK-D6 domain involved in PK and FXI binding and study the importance of the HK-PK and HK-FXI interactions to coagulation. METHODS Twenty-four HK variants with alanine replacements spanning residues 542-613 were tested in PK/FXI binding and activated partial thromboplastin time clotting assays. Surface-induced FXI and PK activation in plasma were studied in the presence or absence of HK. Kng1-/- mice lacking HK were supplemented with human or murine HK and tested in an arterial thrombosis model. RESULTS Overlapping binding sites for PK and FXI were identified in the HK-D6 domain. HK variants with defects only in FXI binding corrected the activated partial thromboplastin time of HK-deficient plasma poorly compared to a variant defective only in PK-binding. In plasma, HK deficiency appeared to have a greater deleterious effect on FXI activation than PK activation. Human HK corrected the defect in arterial thrombus formation in HK-deficient mice poorly due to a specific defect in binding to mouse FXI. CONCLUSION Clinical observations indicate FXI is required for hemostasis, while HK is not. Yet, the HK-FXI interaction is required for contact activation-induced clotting in vitro and in vivo suggesting an important role in thrombosis and perhaps other FXI-related activities.
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Affiliation(s)
- Bassem M Mohammed
- Edward A. Doisy Research Center, Department of Biochemistry and Molecular Biology, St. Louis University School of Medicine, St. Louis, Missouri, USA.
| | - Mao-Fu Sun
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Qiufang Cheng
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Maxim Litvak
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Keith R McCrae
- Department of Hematology and Oncology, Cleveland Clinic, Cleveland, Ohio, USA
| | - Jonas Emsley
- Biodiscovery Institute, School of Pharmacy, University of Nottingham, Nottingham, UK
| | - Owen J T McCarty
- Department of Biomedical Engineering, Division of Hematology/Medical Oncology, School of Medicine, Oregon Health & Science University, Portland, Oregon, USA
| | - David Gailani
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA.
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Fredenburgh JC, Weitz JI. News at XI: moving beyond factor Xa inhibitors. J Thromb Haemost 2023; 21:1692-1702. [PMID: 37116752 DOI: 10.1016/j.jtha.2023.04.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 04/12/2023] [Accepted: 04/12/2023] [Indexed: 04/30/2023]
Abstract
Oral anticoagulants are a mainstay for the prevention and treatment of arterial and venous thrombosis. Direct oral anticoagulants (DOACs) have replaced vitamin K antagonists for many indications. Currently available DOACs include dabigatran, which inhibits thrombin, and apixaban, edoxaban, and rivaroxaban, which inhibit factor (F) Xa. A new class of DOACs is under development. These new DOACs, which include asundexian and milvexian, inhibit FXIa, which is positioned in the intrinsic pathway of coagulation. Anticoagulants that target FXIa have the potential to be safer than the current DOACs because there is emerging evidence that FXI is essential for thrombosis but mostly dispensable for hemostasis. In addition to the oral inhibitors of FXIa, parenteral inhibitors are also under development. These include fesomersen, an antisense oligonucleotide that reduces the hepatic synthesis of FXI; abelacimab, an antibody that binds to FXI and blocks its activation; and osocimab, an FXIa inhibitory antibody. Focusing on these new agents, this article describes the unmet needs in oral anticoagulation therapy, explains why FXI is a promising target for new oral anticoagulants, reviews phase 2 clinical data on new agents, describes ongoing phase 3 trials, and provides a perspective on the opportunities and challenges for FXI inhibitors.
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Affiliation(s)
- James C Fredenburgh
- Department of Medicine, McMaster University, Hamilton, Ontario, Canada; Thrombosis and Atherosclerosis Research Institute, McMaster University, Hamilton, Ontario, Canada
| | - Jeffrey I Weitz
- Department of Medicine, McMaster University, Hamilton, Ontario, Canada; Thrombosis and Atherosclerosis Research Institute, McMaster University, Hamilton, Ontario, Canada; Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada.
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Santostasi G, Denas G, Pengo V. New pharmacotherapeutic options for oral anticoagulant treatment in atrial fibrillation patients aged 65 and older: factor XIa inhibitors and beyond. Expert Opin Pharmacother 2023; 24:1335-1347. [PMID: 37243619 DOI: 10.1080/14656566.2023.2219391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 05/22/2023] [Accepted: 05/25/2023] [Indexed: 05/29/2023]
Abstract
INTRODUCTION Although much progress has been made using anticoagulation for stroke prevention in patients with non-valvular atrial fibrillation, bleeding is still a major concern. AREAS COVERED This article reviews current pharmacotherapeutic options in this setting. Particular emphasis is placed on the ability of the new molecules to minimize the bleeding risk in elderly patients. A systematic search of PubMed, Web of Science, and the Cochrane Library up to March 2023 was carried out. EXPERT OPINION Contact phase of coagulation is a possible new target for anticoagulant therapy. Indeed, congenital or acquired deficiency of contact phase factors is associated with reduced thrombotic burden and limited risk of spontaneous bleeding. These new drugs seem particularly suitable for stroke prevention in elderly patients with non-valvular atrial fibrillation in whom the hemorrhagic risk is high. Most of anti Factor XI (FXI) drugs are for parenteral use only. A group of small molecules are for oral use and therefore are candidates to substitute direct oral anticoagulants (DOACs) for stroke prevention in elderly patients with atrial fibrillation. Doubts remain on the possibility of impaired hemostasis. Indeed, a fine calibration of inhibition of contact phase factors is crucial for an effective and safe treatment.
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Affiliation(s)
| | - Gentian Denas
- Cardiology Clinic, Department of Cardiac, Thoracic, Vascular Sciences and Public Health, Padua University Hospital, Padua, Italy
| | - Vittorio Pengo
- Cardiology Clinic, Department of Cardiac, Thoracic, Vascular Sciences and Public Health, Padua University Hospital, Padua, Italy
- Arianna Foundation on Anticoagulation, Bologna, Italy
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Kluge KE, Seljeflot I, Arnesen H, Jensen T, Halvorsen S, Helseth R. Coagulation factors XI and XII as possible targets for anticoagulant therapy. Thromb Res 2022; 214:53-62. [DOI: 10.1016/j.thromres.2022.04.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 04/04/2022] [Accepted: 04/19/2022] [Indexed: 10/18/2022]
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Feugray G, Kasonga F, Chamouni P, Barbay V, Fresel M, Hélène Chretien M, Brunel S, Le Cam Duchez V, Billoir P. Factor XII deficiency evaluated by thrombin generation assay. Clin Biochem 2021; 100:42-47. [PMID: 34843733 DOI: 10.1016/j.clinbiochem.2021.11.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 11/06/2021] [Accepted: 11/22/2021] [Indexed: 11/03/2022]
Abstract
INTRODUCTION Coagulation factor XII (FXII) plays a role in thrombin generation, fibrinolysis, inflammation, angiogenesis, chemotaxis and diapedesis. FXII deficiency is not associated with bleeding risk unlike other coagulation factors. MATERIALS/METHODS We investigated thrombin generation assay (TGA) profile modification in FXII deficiency and the correlation with TGA and deficiency severity. TGA was performed in platelet poor plasma (PPP) with tissue factor (1 pmol/L) and phospholipid (4 µmol/L) standardized concentration. Thrombin generation profiles were compared in 54 patients with FXII deficiency, 25 healthy controls and 23 patients with hemophilia A (factor VIII (FVIII) deficiency. Patients with FXII deficiency were classified in three groups based on FXII activity (30-50%, 10-29%, <10%). FVIII deficiency was included as a bleeding control group. RESULTS As expected, we found a correlation between FXII deficiency and activated partial thromboplastin time (aPTT). A decrease of thrombin generation was observed in healthy controls and all FXII deficiency groups. A decrease of endogenous thrombin potential (ETP), peak and velocity was observed in patients with FVIII deficiency compared to FXII deficiency. A decrease of thrombin generation was noted in patients with FXII deficiency and bleeding history compared to patients with FXII deficiency and thrombosis history. CONCLUSION In this study, thrombin generation profiles were not sensitive to FXII deficiency. TGA could distinguish bleeding and thrombotic tendency in FXII deficiency. Our results should therefore be considered as exploratory and deserve confirmation.
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Affiliation(s)
- Guillaume Feugray
- Normandie Univ, UNIROUEN, INSERM U1096, Rouen University Hospital, Vascular Hemostasis Unit, F 76000 Rouen, France
| | - Fiston Kasonga
- Rouen University Hospital, Vascular Hemostasis Unit, F 76000 Rouen, France
| | - Pierre Chamouni
- Rouen University Hospital, Hemophilia Care Center, F 76000 Rouen, France
| | - Virginie Barbay
- Rouen University Hospital, Vascular Hemostasis Unit, F 76000 Rouen, France; Rouen University Hospital, Hemophilia Care Center, F 76000 Rouen, France
| | - Marielle Fresel
- Rouen University Hospital, Vascular Hemostasis Unit, F 76000 Rouen, France
| | | | - Sabine Brunel
- Rouen University Hospital, Vascular Hemostasis Unit, F 76000 Rouen, France
| | - Véronique Le Cam Duchez
- Normandie Univ, UNIROUEN, INSERM U1096, Rouen University Hospital, Vascular Hemostasis Unit, F 76000 Rouen, France
| | - Paul Billoir
- Normandie Univ, UNIROUEN, INSERM U1096, Rouen University Hospital, Vascular Hemostasis Unit, F 76000 Rouen, France.
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Abstract
PURPOSE OF REVIEW Anticoagulation with vitamin-K antagonists or direct oral anticoagulants is associated with a significant risk of bleeding. There is a major effort underway to develop antithrombotic drugs that have a smaller impact on hemostasis. The plasma contact proteins factor XI (FXI) and factor XII (FXII) have drawn considerable interest because they contribute to thrombosis but have limited roles in hemostasis. Here, we discuss results of preclinical and clinical trials supporting the hypothesis that the contact system contributes to thromboembolic disease. RECENT FINDINGS Numerous compounds targeting FXI or FXII have shown antithrombotic properties in preclinical studies. In phase 2 studies, drugs-targeting FXI or its protease form FXIa compared favorably with standard care for venous thrombosis prophylaxis in patients undergoing knee replacement. While less work has been done with FXII inhibitors, they may be particularly useful for limiting thrombosis in situations where blood comes into contact with artificial surfaces of medical devices. SUMMARY Inhibitors of contact activation, and particularly of FXI, are showing promise for prevention of thromboembolic disease. Larger studies are required to establish their efficacy, and to establish that they are safer than current therapy from a bleeding standpoint.
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9
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Meini S, Zanichelli A, Sbrojavacca R, Iuri F, Roberts AT, Suffritti C, Tascini C. Understanding the Pathophysiology of COVID-19: Could the Contact System Be the Key? Front Immunol 2020; 11:2014. [PMID: 32849666 PMCID: PMC7432138 DOI: 10.3389/fimmu.2020.02014] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 07/24/2020] [Indexed: 12/20/2022] Open
Abstract
To date the pathophysiology of COVID-19 remains unclear: this represents a factor determining the current lack of effective treatments. In this paper, we hypothesized a complex host response to SARS-CoV-2, with the Contact System (CS) playing a pivotal role in innate immune response. CS is linked with different proteolytic defense systems operating in human vasculature: the Kallikrein–Kinin (KKS), the Coagulation/Fibrinolysis and the Renin–Angiotensin (RAS) Systems. We investigated the role of the mediators involved. CS consists of Factor XII (FXII) and plasma prekallikrein (complexed to high-molecular-weight kininogen-HK). Autoactivation of FXII by contact with SARS-CoV-2 could lead to activation of intrinsic coagulation, with fibrin formation (microthrombosis), and fibrinolysis, resulting in increased D-dimer levels. Activation of kallikrein by activated FXII leads to production of bradykinin (BK) from HK. BK binds to B2-receptors, mediating vascular permeability, vasodilation and edema. B1-receptors, binding the metabolite [des-Arg9]-BK (DABK), are up-regulated during infections and mediate lung inflammatory responses. BK could play a relevant role in COVID-19 as already described for other viral models. Angiotensin-Converting-Enzyme (ACE) 2 displays lung protective effects: it inactivates DABK and converts Angiotensin II (Ang II) into Angiotensin-(1-7) and Angiotensin I into Angiotensin-(1-9). SARS-CoV-2 binds to ACE2 for cell entry, downregulating it: an impaired DABK inactivation could lead to an enhanced activity of B1-receptors, and the accumulation of Ang II, through a negative feedback loop, may result in decreased ACE activity, with consequent increase of BK. Therapies targeting the CS, the KKS and action of BK could be effective for the treatment of COVID-19.
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Affiliation(s)
- Simone Meini
- Internal Medicine Unit, Azienda USL Toscana Centro, Santa Maria Annunziata Hospital, Florence, Italy
| | - Andrea Zanichelli
- General Medicine Unit, ASST Fatebenefratelli Sacco, Ospedale Luigi Sacco-Università degli Studi di Milano, Milan, Italy
| | - Rodolfo Sbrojavacca
- Infectious Diseases Clinic, Santa Maria Misericordia Hospital, Università degli Studi di Udine, Udine, Italy
| | - Federico Iuri
- Department of Emergency, Santa Maria Misericordia Hospital, Università degli Studi di Udine, Udine, Italy
| | | | - Chiara Suffritti
- General Medicine Unit, ASST Fatebenefratelli Sacco, Ospedale Luigi Sacco-Università degli Studi di Milano, Milan, Italy
| | - Carlo Tascini
- Infectious Diseases Clinic, Santa Maria Misericordia Hospital, Università degli Studi di Udine, Udine, Italy
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Vuckovic J, Zdravkovic R, Babovic Stanic K, Majin M, Velicki L. Incidental Detection of Factor XII Deficiency Following Coronary Artery Bypass Grafting. J Cardiothorac Vasc Anesth 2020; 35:597-599. [PMID: 32571656 DOI: 10.1053/j.jvca.2020.05.029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 05/16/2020] [Accepted: 05/18/2020] [Indexed: 02/06/2023]
Affiliation(s)
- Jelena Vuckovic
- Faculty of Medicine, University of Novi Sad, Novi Sad, Serbia; Institute of Cardiovascular Diseases of Vojvodina, Sremska Kamenica, Serbia
| | - Ranko Zdravkovic
- Institute of Cardiovascular Diseases of Vojvodina, Sremska Kamenica, Serbia
| | | | - Marijan Majin
- Institute of Cardiovascular Diseases of Vojvodina, Sremska Kamenica, Serbia
| | - Lazar Velicki
- Faculty of Medicine, University of Novi Sad, Novi Sad, Serbia; Institute of Cardiovascular Diseases of Vojvodina, Sremska Kamenica, Serbia.
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11
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From multi-target anticoagulants to DOACs, and intrinsic coagulation factor inhibitors. Blood Rev 2020; 39:100615. [DOI: 10.1016/j.blre.2019.100615] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2019] [Revised: 08/08/2019] [Accepted: 08/27/2019] [Indexed: 01/10/2023]
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12
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Heterozygous FXII deficiency is not associated with an increased incidence of thrombotic events: Results of a long term study. Blood Cells Mol Dis 2019; 77:8-11. [DOI: 10.1016/j.bcmd.2019.03.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 03/08/2019] [Accepted: 03/10/2019] [Indexed: 11/18/2022]
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13
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Raghunathan V, Zilberman‐Rudenko J, Olson SR, Lupu F, McCarty OJT, Shatzel JJ. The contact pathway and sepsis. Res Pract Thromb Haemost 2019; 3:331-339. [PMID: 31294319 PMCID: PMC6611366 DOI: 10.1002/rth2.12217] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Accepted: 04/15/2019] [Indexed: 12/12/2022] Open
Abstract
The contact pathway factors XI (FXI) and XII (FXII) have been demonstrated to be largely dispensable for hemostasis, as their absence results in a mild to absent bleeding diathesis. A growing body of literature, however, suggests that the contact pathway contributes to the pathologic host response to certain infectious organisms that produces the often-fatal syndrome known as sepsis. The contact pathway factors serve as a central node connecting inflammation to coagulation, and may offer a potentially safe therapeutic target to mitigate the morbidity and mortality associated with sepsis. Herein, we summarize published in vivo and in vitro data that have explored the roles of the contact pathway in sepsis, and discuss potential clinical applications of novel FXI- and FXII-inhibiting drugs currently under investigation.
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Affiliation(s)
- Vikram Raghunathan
- Division of Hematology‐Medical OncologyKnight Cancer InstituteOregon Health & Science UniversityPortlandOregonUSA
| | | | - Sven R. Olson
- Division of Hematology‐Medical OncologyKnight Cancer InstituteOregon Health & Science UniversityPortlandOregonUSA
- Department of Biomedical EngineeringOregon Health & Science UniversityPortlandOregonUSA
| | - Florea Lupu
- Cardiovascular Biology Research ProgramOklahoma Medical Research FoundationOklahoma CityOklahomaUSA
| | - Owen J. T. McCarty
- Department of Biomedical EngineeringOregon Health & Science UniversityPortlandOregonUSA
| | - Joseph J. Shatzel
- Division of Hematology‐Medical OncologyKnight Cancer InstituteOregon Health & Science UniversityPortlandOregonUSA
- Department of Biomedical EngineeringOregon Health & Science UniversityPortlandOregonUSA
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14
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Tillman BF, Gruber A, McCarty OJT, Gailani D. Plasma contact factors as therapeutic targets. Blood Rev 2018; 32:433-448. [PMID: 30075986 PMCID: PMC6185818 DOI: 10.1016/j.blre.2018.04.001] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Revised: 03/27/2018] [Accepted: 04/06/2018] [Indexed: 12/20/2022]
Abstract
Direct oral anticoagulants (DOACs) are small molecule inhibitors of the coagulation proteases thrombin and factor Xa that demonstrate comparable efficacy to warfarin for several common indications, while causing less serious bleeding. However, because their targets are required for the normal host-response to bleeding (hemostasis), DOACs are associated with therapy-induced bleeding that limits their use in certain patient populations and clinical situations. The plasma contact factors (factor XII, factor XI, and prekallikrein) initiate blood coagulation in the activated partial thromboplastin time assay. While serving limited roles in hemostasis, pre-clinical and epidemiologic data indicate that these proteins contribute to pathologic coagulation. It is anticipated that drugs targeting the contact factors will reduce risk of thrombosis with minimal impact on hemostasis. Here, we discuss the biochemistry of contact activation, the contributions of contact factors in thrombosis, and novel antithrombotic agents targeting contact factors that are undergoing pre-clinical and early clinical testing.
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Affiliation(s)
- Benjamin F Tillman
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Andras Gruber
- Department of Biomedical Engineering, Oregon Health & Sciences University, Portland, OR, USA; Division of Hematology and Medical Oncology School of Medicine, Oregon Health & Sciences University, Portland, OR, USA; Aronora, Inc., Portland, OR, USA
| | - Owen J T McCarty
- Department of Biomedical Engineering, Oregon Health & Sciences University, Portland, OR, USA; Division of Hematology and Medical Oncology School of Medicine, Oregon Health & Sciences University, Portland, OR, USA
| | - David Gailani
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA; Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA.
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15
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De Maat S, Hofman ZLM, Maas C. Hereditary angioedema: the plasma contact system out of control. J Thromb Haemost 2018; 16:1674-1685. [PMID: 29920929 DOI: 10.1111/jth.14209] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Accepted: 06/11/2018] [Indexed: 01/06/2023]
Abstract
The plasma contact system contributes to thrombosis in experimental models. Even though our standard blood coagulation tests are prolonged when plasma lacks contact factors, this enzyme system appears to have a minor (if any) role in hemostasis. In this review, we explore the clinical phenotype of C1 esterase inhibitor (C1-INH) deficiency. C1-INH is the key plasma inhibitor of the contact system enzymes, and its deficiency causes hereditary angioedema (HAE). This inflammatory disorder is characterized by recurrent aggressive attacks of tissue swelling that occur at unpredictable locations throughout the body. Bradykinin, which is considered to be a byproduct of the plasma contact system during in vitro coagulation, is the main disease mediator in HAE. Surprisingly, there is little evidence for thrombotic events in HAE patients, suggesting mechanistic uncoupling from the intrinsic pathway of coagulation. In addition, it is questionable whether a surface is responsible for contact system activation in HAE. In this review, we discuss the clinical phenotype, disease modifiers and diagnostic challenges of HAE. We subsequently describe the underlying biochemical mechanisms and contributing disease mediators. Furthermore, we review three types of HAE that are not caused by C1-INH inhibitor deficiency. Finally, we propose a central enzymatic axis that we hypothesize to be responsible for bradykinin production in health and disease.
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Affiliation(s)
- S De Maat
- Department of Clinical Chemistry and Haematology, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Z L M Hofman
- Department of Clinical Chemistry and Haematology, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - C Maas
- Department of Clinical Chemistry and Haematology, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
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16
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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] [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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17
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Tillman B, Gailani D. Inhibition of Factors XI and XII for Prevention of Thrombosis Induced by Artificial Surfaces. Semin Thromb Hemost 2017; 44:60-69. [PMID: 28898903 DOI: 10.1055/s-0037-1603937] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Exposure of blood to a variety of artificial surface induces contact activation, a process that contributes to the host innate response to foreign substances. On the foreign surface, the contact factors, factor XII (FXII), and plasma prekallikrein undergo reciprocal conversion to their fully active protease forms (FXIIa and α-kallikrein, respectively) by a process supported by the cofactor high-molecular-weight kininogen. Contact activation can trigger blood coagulation by conversion of factor XI (FXI) to the protease FXIa. There is interest in developing therapeutic inhibitors to FXIa and FXIIa because these activated factors can contribute to thrombosis in certain situations. Drugs targeting these proteases may be particularly effective in thrombosis triggered by exposure of blood to the surfaces of implantable medical devices. Here, we review clinical data supporting roles for FXII and FXI in thrombosis induced by medical devices, and preclinical data suggesting that therapeutic targeting of these proteins may limit surface-induced thrombosis.
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Affiliation(s)
- Benjamin Tillman
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
| | - David Gailani
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee.,Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee
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18
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Wheeler AP, Gailani D. The Intrinsic Pathway of Coagulation as a Target for Antithrombotic Therapy. Hematol Oncol Clin North Am 2017; 30:1099-114. [PMID: 27637310 DOI: 10.1016/j.hoc.2016.05.007] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Plasma coagulation in the activated partial thromboplastin time assay is initiated by sequential activation of coagulation factors XII, XI, and IX. While this series of proteolytic reactions is not an accurate model for hemostasis in vivo, there is mounting evidence that factor XI and factor XII contribute to thrombosis, and that inhibiting them can produce an antithrombotic effect with a small effect on hemostasis. This article discusses the contributions of components of the intrinsic pathway to thrombosis in animal models and humans, and results of early clinical trials of drugs targeting factors IX, XI, and XII.
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Affiliation(s)
- Allison P Wheeler
- Department of Pathology, Microbiology and Immunology, Vanderbilt University, C-3321A Medical Center North, 1161 21st Avenue, Nashville, TN 37232, USA; Department of Pediatrics, Vanderbilt University, 397 Preston Research Building, 2220 Pierce Ave, Nashville, TN 37232, USA.
| | - David Gailani
- Department of Pathology, Microbiology and Immunology, Vanderbilt University, C-3321A Medical Center North, 1161 21st Avenue, Nashville, TN 37232, USA; Hematology/Oncology Division, Department of Medicine, Vanderbilt University, 777 Preston Research Building, 2220 Pierce Avenue, Nashville, TN 37232, USA
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19
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Johansson K, Jansson JH, Johansson L, Bylesjö I, Nilsson TK, Eliasson M, Söderberg S, Lind M. Factor XII as a Risk Marker for Hemorrhagic Stroke: A Prospective Cohort Study. Cerebrovasc Dis Extra 2017; 7:84-94. [PMID: 28433996 PMCID: PMC5437482 DOI: 10.1159/000468994] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Accepted: 02/10/2017] [Indexed: 01/15/2023] Open
Abstract
Background Coagulation factor XII (FXII) is involved in pathological thrombus formation and is a suggested target of anticoagulants. It is unclear whether FXII levels are correlated with cardiovascular risk factors and whether they are associated with myocardial infarction or ischemic or hemorrhagic stroke. The aim of this study was to investigate the correlation between FXII and cardiovascular risk factors in the general population. We also aimed to study the associations between FXII levels and future myocardial infarction and ischemic and hemorrhagic stroke. Methods This prospective cohort study measured FXII levels in 1,852 randomly selected participants in a health survey performed in northern Sweden in 1994. Participants were followed until myocardial infarction, stroke, death, or until December 31, 2011. Results During the median follow-up of 17.9 years, 165 individuals were diagnosed with myocardial infarction, 108 with ischemic stroke, and 30 with hemorrhagic stroke. There were weak correlations between FXII and body mass index, cholesterol, and hypertension. There was no association between FXII and myocardial infarction or ischemic stroke, neither in univariable Cox regression analysis nor after adjustment for age, sex, smoking, body mass index, cholesterol, hypertension, and diabetes. In univariable Cox regression analysis, the hazard ratio for the association between FXII levels and hemorrhagic stroke was 1.42 per SD (95% confidence interval: 0.99–2.05). In the multivariable model, higher levels of FXII were associated with increased risk of hemorrhagic stroke (hazard ratio 1.51 per SD; 95% confidence interval: 1.03–2.21). Conclusion We found an independent association between FXII levels and the risk of hemorrhagic stroke, but not between FXII levels and ischemic stroke or myocardial infarction.
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Affiliation(s)
- Kristina Johansson
- Department of Public Health and Clinical Medicine, Skellefteå Research Unit, Umeå University, Umeå, Sweden
| | - Jan-Håkan Jansson
- Department of Public Health and Clinical Medicine, Skellefteå Research Unit, Umeå University, Umeå, Sweden
| | - Lars Johansson
- Department of Public Health and Clinical Medicine, Skellefteå Research Unit, Umeå University, Umeå, Sweden
| | - Ingemar Bylesjö
- Department of Public Health and Clinical Medicine, Family Medicine, Umeå University, Umeå, Sweden
| | - Torbjörn K Nilsson
- Department of Medical Biosciences/Clinical Chemistry, Umeå University, Umeå, Sweden
| | - Mats Eliasson
- Department of Public Health and Clinical Medicine, Sunderby Research Unit, Umeå University, Umeå, Sweden
| | - Stefan Söderberg
- Department of Public Health and Clinical Medicine, Umeå University, Umeå, Sweden
| | - Marcus Lind
- Department of Public Health and Clinical Medicine, Skellefteå Research Unit, Umeå University, Umeå, Sweden
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20
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Nickel KF, Long AT, Fuchs TA, Butler LM, Renné T. Factor XII as a Therapeutic Target in Thromboembolic and Inflammatory Diseases. Arterioscler Thromb Vasc Biol 2017; 37:13-20. [DOI: 10.1161/atvbaha.116.308595] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2016] [Accepted: 11/01/2016] [Indexed: 01/08/2023]
Abstract
Coagulation factor XII (FXII, Hageman factor) is a plasma protease that in its active form (FXIIa) initiates the procoagulant and proinflammatory contact system. This name arises from FXII’s unique mechanism of activation that is induced by binding (contact) to negatively charged surfaces. Various substances have the capacity to trigger FXII contact-activation in vivo including mast cell–derived heparin, misfolded protein aggregates, collagen, nucleic acids, and polyphosphate. FXII deficiency is not associated with bleeding, and for decades, the factor was considered to be dispensable for coagulation in vivo. However, despite the fact that humans and animals with deficiency in FXII have a normal hemostatic capacity, animal models revealed a critical role of FXIIa-driven coagulation in thromboembolic diseases. In addition to its role in thrombosis, FXIIa contributes to inflammation through the activation of the inflammatory bradykinin-producing kallikrein-kinin system. Pharmacological inhibition of FXII/FXIIa interferes with thrombosis and inflammation in animal models. Thus, targeting the FXIIa-driven contact system seems to be a promising and safe therapeutic anticoagulation treatment strategy, with additional anti-inflammatory effects. Here, we discuss novel functions of FXIIa in cardiovascular thrombotic and inflammatory disorders.
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Affiliation(s)
- Katrin F. Nickel
- From the Institute of Clinical Chemistry and Laboratory Medicine, University Medical Center Hamburg-Eppendorf, Germany (K.F.N., A.T.L., T.A.F., L.M.B., T.R.); and Division of Clinical Chemistry, Department of Molecular Medicine and Surgery, Karolinska Institutet and University Hospital, Stockholm, Sweden (K.F.N., T.A.F., L.M.B., T.R.)
| | - Andy T. Long
- From the Institute of Clinical Chemistry and Laboratory Medicine, University Medical Center Hamburg-Eppendorf, Germany (K.F.N., A.T.L., T.A.F., L.M.B., T.R.); and Division of Clinical Chemistry, Department of Molecular Medicine and Surgery, Karolinska Institutet and University Hospital, Stockholm, Sweden (K.F.N., T.A.F., L.M.B., T.R.)
| | - Tobias A. Fuchs
- From the Institute of Clinical Chemistry and Laboratory Medicine, University Medical Center Hamburg-Eppendorf, Germany (K.F.N., A.T.L., T.A.F., L.M.B., T.R.); and Division of Clinical Chemistry, Department of Molecular Medicine and Surgery, Karolinska Institutet and University Hospital, Stockholm, Sweden (K.F.N., T.A.F., L.M.B., T.R.)
| | - Lynn M. Butler
- From the Institute of Clinical Chemistry and Laboratory Medicine, University Medical Center Hamburg-Eppendorf, Germany (K.F.N., A.T.L., T.A.F., L.M.B., T.R.); and Division of Clinical Chemistry, Department of Molecular Medicine and Surgery, Karolinska Institutet and University Hospital, Stockholm, Sweden (K.F.N., T.A.F., L.M.B., T.R.)
| | - Thomas Renné
- From the Institute of Clinical Chemistry and Laboratory Medicine, University Medical Center Hamburg-Eppendorf, Germany (K.F.N., A.T.L., T.A.F., L.M.B., T.R.); and Division of Clinical Chemistry, Department of Molecular Medicine and Surgery, Karolinska Institutet and University Hospital, Stockholm, Sweden (K.F.N., T.A.F., L.M.B., T.R.)
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21
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The initiation and effects of plasma contact activation: an overview. Int J Hematol 2016; 105:235-243. [PMID: 27848184 DOI: 10.1007/s12185-016-2132-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Revised: 10/31/2016] [Accepted: 11/02/2016] [Indexed: 10/20/2022]
Abstract
The plasma contact system sits atop the intrinsic coagulation cascade and plasma kallikrein-kinin pathway, and in vivo its activation contributes, respectively, to coagulation and inflammation mainly via two downstream pathways. This system has been widely investigated, its activation mechanisms by negatively charged surfaces and the interactions within its components, factor XII, prekallikrein and high molecular weight kininogen are well understood at the biochemical level. However, as most of the activators that have been discovered by in vitro experiments are exogenous, the physiological activators and roles of the contact system have remained unclear and controversial. In the last two decades, several physiological activators have been identified, and a better understanding of its roles and its connection with other signaling pathways has been obtained from in vivo studies. In this article, we present an overview of the contact pathway with a focus on the activation mechanisms, natural stimuli, possible physiological roles, potential risks of its excessive activation, remaining questions and future prospects.
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22
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Coagulation factor abnormalities related to discordance between anti-factor Xa and activated partial thromboplastin time in patients supported with continuous-flow left ventricular assist devices. J Heart Lung Transplant 2016; 35:1311-1320. [DOI: 10.1016/j.healun.2016.09.010] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Revised: 09/07/2016] [Accepted: 09/16/2016] [Indexed: 11/20/2022] Open
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23
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ten Cate-Hoek AJ, Weitz JI, Gailani D, Meijer K, Philippou H, Bouman AC, Whitney Cheung Y, van Mens TE, Govers-Riemslag JW, Vries M, Bleker S, Biedermann JS, Stoof SCM, Buller HR. Theme 3: Non-invasive management of (recurrent) venous thromboembolism (VTE) and post thrombotic syndrome (PTS). Thromb Res 2016; 136 Suppl 1:S13-8. [PMID: 26387731 DOI: 10.1016/j.thromres.2015.07.036] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Arina J ten Cate-Hoek
- Maastricht University Medical Center, Laboratory for Clinical Thrombosis and Hemostasis, Cardiovascular Research Institute Maastricht (CARIM), Netherlands; Thrombosis Center, USA.
| | - Jeffrey I Weitz
- McMaster University and Thrombosis and Atherosclerosis Research Institute, Canada
| | - David Gailani
- Vanderbilt University, Department of Pathology, Microbiology and Immunology, Nashville, USA
| | - Karina Meijer
- University of Groningen, University Medical Center Groningen, Department of Hematology, Netherlands
| | - Helen Philippou
- University of Leeds, Division of Cardiovascular and Diabetes Research, The LIGHT Labs, Leeds, UK
| | - Annemieke C Bouman
- Maastricht University Medical Center, Laboratory for Clinical Thrombosis and Hemostasis, Cardiovascular Research Institute Maastricht (CARIM), Netherlands; Thrombosis Center, USA
| | - Y Whitney Cheung
- University of Amsterdam, Academic Medical Center, Department of Vascular Medicine, Netherlands
| | - Thijs E van Mens
- University of Amsterdam, Academic Medical Center, Department of Vascular Medicine, Netherlands
| | - Jose W Govers-Riemslag
- Maastricht University Medical Center, Laboratory for Clinical Thrombosis and Hemostasis, Cardiovascular Research Institute Maastricht (CARIM), Netherlands
| | - Minka Vries
- Maastricht University Medical Center, Laboratory for Clinical Thrombosis and Hemostasis, Cardiovascular Research Institute Maastricht (CARIM), Netherlands
| | - Suzanne Bleker
- University of Amsterdam, Academic Medical Center, Department of Vascular Medicine, Netherlands
| | - Jossi S Biedermann
- Erasmus University Medical Center, Rotterdam, Department of Hematology, Netherlands
| | - S Carina M Stoof
- Erasmus University Medical Center, Rotterdam, Department of Hematology, Netherlands
| | - Harry R Buller
- University of Amsterdam, Academic Medical Center, Department of Vascular Medicine, Netherlands
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24
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Kenne E, Nickel KF, Long AT, Fuchs TA, Stavrou EX, Stahl FR, Renné T. Factor XII: a novel target for safe prevention of thrombosis and inflammation. J Intern Med 2015; 278:571-85. [PMID: 26373901 DOI: 10.1111/joim.12430] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Plasma protein factor XII (FXII) activates the procoagulant and proinflammatory contact system that drives both the kallikrein-kinin system and the intrinsic pathway of coagulation. When zymogen FXII comes into contact with negatively charged surfaces, it auto-activates to the serine proteaseactivated FXII (FXIIa). Recently, various in vivo activators of FXII have been identified including heparin, misfolded protein aggregates, polyphosphate and nucleic acids. Murine models have established a central role of FXII in arterial and venous thrombosis. Despite its central function in thrombosis, deficiency in FXII does not impair haemostasis in animals and humans. In a preclinical cardiopulmonary bypass system in large animals, the FXIIa-blocking antibody 3F7 prevented thrombosis; however, in contrast to traditional anticoagulants, bleeding was not increased. In addition to its function in thrombosis, FXIIa initiates formation of the inflammatory mediator bradykinin. This mediator increases vascular leak, causes vasodilation, and induces chemotaxis with implications for septic, anaphylactic and allergic disease states. Therefore, targeting FXIIa appears to be a promising strategy for thromboprotection without associated bleeding risks but with anti-inflammatory properties.
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Affiliation(s)
- E Kenne
- Division of Clinical Chemistry, Department of Molecular Medicine and Surgery, Karolinska Institutet and University Hospital, Stockholm, Sweden.,Center of Molecular Medicine, Karolinska Institutet and University Hospital, Stockholm, Sweden
| | - K F Nickel
- Division of Clinical Chemistry, Department of Molecular Medicine and Surgery, Karolinska Institutet and University Hospital, Stockholm, Sweden.,Center of Molecular Medicine, Karolinska Institutet and University Hospital, Stockholm, Sweden.,Institute of Clinical Chemistry and Laboratory Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - A T Long
- Department of Medicine, Hematology and Oncology Division, Case Western Reserve University and Louis Stokes Cleveland VA Medical Center, Cleveland, OH, USA
| | - T A Fuchs
- Division of Clinical Chemistry, Department of Molecular Medicine and Surgery, Karolinska Institutet and University Hospital, Stockholm, Sweden.,Center of Molecular Medicine, Karolinska Institutet and University Hospital, Stockholm, Sweden.,Institute of Clinical Chemistry and Laboratory Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - E X Stavrou
- Department of Medicine, Hematology and Oncology Division, Case Western Reserve University and Louis Stokes Cleveland VA Medical Center, Cleveland, OH, USA
| | - F R Stahl
- Institute of Clinical Chemistry and Laboratory Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - T Renné
- Division of Clinical Chemistry, Department of Molecular Medicine and Surgery, Karolinska Institutet and University Hospital, Stockholm, Sweden.,Center of Molecular Medicine, Karolinska Institutet and University Hospital, Stockholm, Sweden.,Institute of Clinical Chemistry and Laboratory Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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25
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Baeriswyl V, Calzavarini S, Chen S, Zorzi A, Bologna L, Angelillo-Scherrer A, Heinis C. A Synthetic Factor XIIa Inhibitor Blocks Selectively Intrinsic Coagulation Initiation. ACS Chem Biol 2015; 10:1861-70. [PMID: 25989088 DOI: 10.1021/acschembio.5b00103] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Coagulation factor XII (FXII) inhibitors are of interest for the study of the protease in the intrinsic coagulation pathway, for the suppression of contact activation in blood coagulation assays, and they have potential application in antithrombotic therapy. However, synthetic FXII inhibitors developed to date have weak binding affinity and/or poor selectivity. Herein, we developed a peptide macrocycle that inhibits activated FXII (FXIIa) with an inhibitory constant Ki of 22 nM and a selectivity of >2000-fold over other proteases. Sequence and structure analysis revealed that one of the two macrocyclic rings of the in vitro evolved peptide mimics the combining loop of corn trypsin inhibitor, a natural protein-based inhibitor of FXIIa. The synthetic inhibitor blocked intrinsic coagulation initiation without affecting extrinsic coagulation. Furthermore, the peptide macrocycle efficiently suppressed plasma coagulation triggered by contact of blood with sample tubes and allowed specific investigation of tissue factor initiated coagulation.
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Affiliation(s)
- Vanessa Baeriswyl
- Institute
of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Sara Calzavarini
- University
Clinic of Hematology and Central Hematology Laboratory, Bern University Hospital and the University of Bern, Inselspital, CH-3010 Bern, Switzerland
- Department
of Clinical Research, University of Bern, CH-3010 Bern, Switzerland
| | - Shiyu Chen
- Institute
of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Alessandro Zorzi
- Institute
of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Luca Bologna
- University
Clinic of Hematology and Central Hematology Laboratory, Bern University Hospital and the University of Bern, Inselspital, CH-3010 Bern, Switzerland
- Department
of Clinical Research, University of Bern, CH-3010 Bern, Switzerland
| | - Anne Angelillo-Scherrer
- University
Clinic of Hematology and Central Hematology Laboratory, Bern University Hospital and the University of Bern, Inselspital, CH-3010 Bern, Switzerland
- Department
of Clinical Research, University of Bern, CH-3010 Bern, Switzerland
| | - Christian Heinis
- Institute
of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
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26
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Gailani D, Bane CE, Gruber A. Factor XI and contact activation as targets for antithrombotic therapy. J Thromb Haemost 2015; 13:1383-95. [PMID: 25976012 PMCID: PMC4516614 DOI: 10.1111/jth.13005] [Citation(s) in RCA: 96] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Accepted: 05/01/2015] [Indexed: 11/26/2022]
Abstract
The most commonly used anticoagulants produce therapeutic antithrombotic effects either by inhibiting thrombin or factor Xa (FXa) or by lowering the plasma levels of the precursors of these key enzymes, prothrombin and FX. These drugs do not distinguish between thrombin generation contributing to thrombosis from thrombin generation required for hemostasis. Thus, anticoagulants increase bleeding risk, and many patients who would benefit from therapy go untreated because of comorbidities that place them at unacceptable risk for hemorrhage. Studies in animals demonstrate that components of the plasma contact activation system contribute to experimentally induced thrombosis, despite playing little or no role in hemostasis. Attention has focused on FXII, the zymogen of a protease (FXIIa) that initiates contact activation when blood is exposed to foreign surfaces, and FXI, the zymogen of the protease FXIa, which links contact activation to the thrombin generation mechanism. In the case of FXI, epidemiologic data indicate this protein contributes to stroke and venous thromboembolism, and perhaps myocardial infarction, in humans. A phase 2 trial showing that reduction of FXI may be more effective than low molecular weight heparin at preventing venous thrombosis during knee replacement surgery provides proof of concept for the premise that an antithrombotic effect can be uncoupled from an anticoagulant effect in humans by targeting components of contact activation. Here, we review data on the role of FXI and FXII in thrombosis and results of preclinical and human trials for therapies targeting these proteins.
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Affiliation(s)
- David Gailani
- Department of Pathology, Microbiology and Immunology, Vanderbilt University, Nashville, Tennessee, USA
| | - Charles E. Bane
- Department of Pathology, Microbiology and Immunology, Vanderbilt University, Nashville, Tennessee, USA
| | - Andras Gruber
- Department of Biomedical Engineering, Oregon Health & Science University, Portland, OR
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27
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Mannhalter C. Biomarkers for arterial and venous thrombotic disorders. Hamostaseologie 2015; 34:115-20, 122-6, 128-30, passim. [PMID: 24819458 DOI: 10.5482/hamo-13-08-0041] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Accepted: 03/21/2014] [Indexed: 02/06/2023] Open
Abstract
The haemostatic system maintains the blood in a fluid state, but allows rapid clot formation at sites of vascular injury to prevent excessive bleeding. Unbalances within the haemostatic system can lead to thrombosis. Inspite of successful research our understanding of the disease pathogenesis is still incomplete. There is great hope that genetic, genomic, and epigenetic discoveries will enhance the diagnostic capability, and improve the treatment options. During the preceding 20 years, the identification of polymorphisms and the elucidation of their role in arterial and venous thromboses became an important area of research. Today, a large body of data is available regarding associations of single nucleotide polymorphisms (SNPs) in candidate genes with plasma concentrations and e. g. the risk of ischaemic stroke or myocardial infarction. However, the results for individual polymorphisms and genes are often controversial. It is now well established that besides acquired also hereditary risk factors influence the occurrence of thrombotic events, and environmental factors may add to this risk. Currently available statistical methods are only able to identify combined risk genotypes if very large patient collectives (>10,000 cases) are tested, and appropriate algorithms to evaluate the data have yet to be developed. Further research is needed to understand the functional effects of genetic variants in genes of blood coagulation proteins that are critical to the pathogenesis of arterial and venous thrombotic disorders. In this review genetic variants in selected genes of the haemostatic system and their relevance for arterial and venous thrombosis will be discussed.
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Affiliation(s)
- C Mannhalter
- Univ.-Prof. Dr. Christine Mannhalter Dept. Laboratory Medicine, Medical University Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria, Tel. +43/1/404 00 20 85, Fax +43/1/404 00 20 97, E-mail:
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28
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Gailani D. Future prospects for contact factors as therapeutic targets. HEMATOLOGY. AMERICAN SOCIETY OF HEMATOLOGY. EDUCATION PROGRAM 2014; 2014:52-59. [PMID: 25696834 PMCID: PMC4364029 DOI: 10.1182/asheducation-2014.1.52] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Anticoagulants currently used in clinical practice to treat or prevent thromboembolic disease are effective, but place patients at increased risk for serious bleeding because they interfere with plasma enzymes (thrombin and factor Xa) that are essential for hemostasis. In the past 10 years, work with genetically altered mice and studies in baboons and rabbits have demonstrated that the plasma contact proteases factor XI, factor XII, and prekallikrein contribute to the formation of occlusive thrombi despite having limited roles in hemostasis. In the case of factor XI, epidemiologic data from human populations indicate that elevated levels of this protein increase risk for stroke and venous thromboembolism and may also influence risk for myocardial infarction. These findings suggest that inhibiting contact activation may produce an antithrombotic effect without significantly compromising hemostasis. This chapter reviews strategies that are being developed for therapeutic targeting of factor XI and factor XII and their performances in preclinical and early human trials.
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Affiliation(s)
- David Gailani
- Department of Pathology, Microbiology and Immunology, Vanderbilt University, Nashville, TN
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29
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Abstract
Abstract
Currently available evidence supports the contention that elevated levels of factor XI (fXI) are associated with a greater risk of venous thromboembolism and ischemic stroke, but, less convincingly, with myocardial infarction. Conversely, reduced plasma levels of fXI seem to offer some protection from venous thromboembolism and stroke, but not myocardial infarction. Factor XI-deficient patients are at risk for certain types of bleeding, particularly posttraumatic hemorrhage on mucosal surfaces where there is a high endogenous fibrinolytic activity. In contrast, the situation with fXII in human thrombosis remains enigmatic. Deficiency of fXII is clearly not associated with any bleeding risk, but neither does it seem to be protective against thrombosis. The longstanding debate as to whether partial fXII deficiency represents a risk factor for thrombosis remains unresolved, with seemingly conflicting results depending on study design, type of assay used, and analyte evaluated. The possibility that elevated fXII levels represent a risk factor for thrombosis is not borne out in the literature.
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30
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Kraft P, Drechsler C, Gunreben I, Heuschmann PU, Kleinschnitz C. Regulation of Blood Coagulation Factors XI and XII in Patients with Acute and Chronic Cerebrovascular Disease: A Case-Control Study. Cerebrovasc Dis 2014; 38:337-43. [DOI: 10.1159/000368434] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Accepted: 09/16/2014] [Indexed: 11/19/2022] Open
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31
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Alias S, Lang IM. Coagulation and the vessel wall in pulmonary embolism. Pulm Circ 2014; 3:728-38. [PMID: 25006391 DOI: 10.1086/674768] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2012] [Accepted: 08/05/2013] [Indexed: 01/28/2023] Open
Abstract
Venous thromboembolism comprises deep-vein thrombosis, thrombus in transit, acute pulmonary embolism, and chronic thromboembolic pulmonary hypertension (CTEPH). Pulmonary thromboemboli commonly resolve, with restoration of normal pulmonary hemodynamics. When they fail to resorb, permanent occlusion of the deep veins and/or CTEPH are the consequences. Apart from endogenous fibrinolysis, venous thrombi resolve by a process of mechanical fragmentation, through organization of the thromboembolus by invasion of endothelial cells, leukocytes, and fibroblasts leading to recanalization. Recent data utilizing various models have contributed to a better understanding of venous thrombosis and the resolution process that is directed at maintaining vascular patency. This review summarizes the plasmatic and cellular components of venous thrombus formation and resolution.
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Affiliation(s)
- Sherin Alias
- Department of Internal Medicine II, Division of Cardiology, Medical University of Vienna, Vienna, Austria
| | - Irene M Lang
- Department of Internal Medicine II, Division of Cardiology, Medical University of Vienna, Vienna, Austria
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Siegerink B, Rosendaal FR, Algra A. Antigen levels of coagulation factor XII, coagulation factor XI and prekallikrein, and the risk of myocardial infarction and ischemic stroke in young women. J Thromb Haemost 2014; 12:606-13. [PMID: 24977287 DOI: 10.1111/jth.12531] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND High levels of activated protein–inhibitor complexes of the intrinsic coagulation proteins are associated with ischemic stroke (IS) but not with myocardial infarction (MI). This study was aimed at determining whether the antigen levels of coagulation factors(factor XII, FXII, and FXI and prekallikrein (PK)are associated with MI and IS, and whether this association is independent of levels of activated protein–inhibitor complexes. PATIENTS AND METHODS The RATIO study included young women (< 50 years) with MI (N = 205)and IS (N = 175), and 638 healthy controls. Antigen levels of FXII, FXI and PK were measured and expressed as percentages of of those in pooled normal plasmas. Odds ratios (ORs) and corresponding 99% confidence intervals (CIs) were calculated for high levels (i.e. ≥ 90th percentile of controls) as measures of rate ratios. RESULTS After adjustment for potential confounders, high levels of FXII antigen were not associated with MI risk or IS risk(OR(MI) 1.18, 99% CI 0.51–2.74; ORIS 1.03, 9% CI 0.41–2.55). High levels of FXI antigen were slightly associated with an increase in MI risk (OR(MI) 1.55, 9% CI 0.74–3.21), whereas there was a substantial association with IS risk (ORIS 2.65, 9% CI 1.27–5.56). PK antigen was slightly associated with MI risk but not with IS risk(ORMI 1.54, 9% CI 0.67–3.52; ORIS 0.90, 9% CI 0.35–2.33). All associations remained similar after adjustment for levels of protein–inhibitor complexes. CONCLUSION Increased levels of FXI antigen were associated with an increase in IS risk, whereas they showed only a marginal association with MI risk. FXII antigen and PK antigen levels were not substantially associated with MI risk and IS risk.
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de Maat S, Tersteeg C, Herczenik E, Maas C. Tracking down contact activation - from coagulationin vitroto inflammationin vivo. Int J Lab Hematol 2014; 36:374-81. [DOI: 10.1111/ijlh.12222] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Accepted: 02/28/2014] [Indexed: 02/07/2023]
Affiliation(s)
- S. de Maat
- Department of Clinical Chemistry and Haematology; University Medical Center Utrecht; Utrecht the Netherlands
| | - C. Tersteeg
- Department of Clinical Chemistry and Haematology; University Medical Center Utrecht; Utrecht the Netherlands
| | - E. Herczenik
- Department of Clinical Chemistry and Haematology; University Medical Center Utrecht; Utrecht the Netherlands
| | - C. Maas
- Department of Clinical Chemistry and Haematology; University Medical Center Utrecht; Utrecht the Netherlands
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Abstract
In this issue of Blood, Matafonov et al demonstrate that an inhibiting monoclonal antibody against coagulation factor XII (fXII) reduces fibrin formation and platelet accumulation in a primate thrombosis model.1
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Abstract
The plasma zymogens factor XII (fXII) and factor XI (fXI) contribute to thrombosis in a variety of mouse models. These proteins serve a limited role in hemostasis, suggesting that antithrombotic therapies targeting them may be associated with low bleeding risks. Although there is substantial epidemiologic evidence supporting a role for fXI in human thrombosis, the situation is not as clear for fXII. We generated monoclonal antibodies (9A2 and 15H8) against the human fXII heavy chain that interfere with fXII conversion to the protease factor XIIa (fXIIa). The anti-fXII antibodies were tested in models in which anti-fXI antibodies are known to have antithrombotic effects. Both anti-fXII antibodies reduced fibrin formation in human blood perfused through collagen-coated tubes. fXII-deficient mice are resistant to ferric chloride-induced arterial thrombosis, and this resistance can be reversed by infusion of human fXII. 9A2 partially blocks, and 15H8 completely blocks, the prothrombotic effect of fXII in this model. 15H8 prolonged the activated partial thromboplastin time of baboon and human plasmas. 15H8 reduced fibrin formation in collagen-coated vascular grafts inserted into arteriovenous shunts in baboons, and reduced fibrin and platelet accumulation downstream of the graft. These findings support a role for fXII in thrombus formation in primates.
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Molecular analysis of factor XII gene in Thai patients with factor XII deficiency. Blood Coagul Fibrinolysis 2013; 24:599-604. [DOI: 10.1097/mbc.0b013e32835fde9d] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Madsen DE, Sidelmann JJ, Overgaard K, Koch C, Gram JB. ELISA for determination of total coagulation factor XII concentration in human plasma. J Immunol Methods 2013; 394:32-9. [DOI: 10.1016/j.jim.2013.04.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2012] [Revised: 04/17/2013] [Accepted: 04/22/2013] [Indexed: 11/25/2022]
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Activation of the contact system in patients with a first acute myocardial infarction. Thromb Res 2013; 132:138-42. [DOI: 10.1016/j.thromres.2013.05.016] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2013] [Revised: 04/12/2013] [Accepted: 05/21/2013] [Indexed: 11/22/2022]
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Puy C, Tucker EI, Wong ZC, Gailani D, Smith SA, Choi SH, Morrissey JH, Gruber A, McCarty OJT. Factor XII promotes blood coagulation independent of factor XI in the presence of long-chain polyphosphates. J Thromb Haemost 2013; 11:1341-52. [PMID: 23659638 PMCID: PMC3714337 DOI: 10.1111/jth.12295] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2012] [Indexed: 11/30/2022]
Abstract
BACKGROUND Inorganic polyphosphates (polyP), which are secreted by activated platelets (short-chain polyP) and accumulate in some bacteria (long-chain polyP), support the contact activation of factor XII (FXII) and accelerate the activation of FXI. OBJECTIVES The aim of the present study was to evaluate the role of FXI in polyP-mediated coagulation activation and experimental thrombus formation. METHODS AND RESULTS Pretreatment of plasma with antibodies that selectively inhibit FXI activation by activated FXII (FXIIa) or FIX) activation by activated FXI (FXIa) were not able to inhibit the procoagulant effect of long or short-chain polyP in plasma. In contrast, the FXIIa inhibitor, corn trypsin inhibitor, blocked the procoagulant effect of long and short polyP in plasma. In a purified system, long polyP significantly enhanced the rate of FXII and prekallikrein activation and the activation of FXI by thrombin but not by FXIIa. In FXI-deficient plasma, long polyP promoted clotting of plasma in an FIX-dependent manner. In a purified system, the activation of FXII and prekallikrein by long polyP promoted FIX activation and prothombin activation. In an ex vivo model of occlusive thrombus formation, inhibition of FXIIa with corn trypsin inhibitor but not of FXI with a neutralizing antibodies abolished the prothrombotic effect of long polyP. CONCLUSIONS We propose that long polyP promotes FXII-mediated blood coagulation bypassing FXI. Accordingly, some polyp-containing pathogens may have evolved strategies to exploit polyP-initiated FXII activation for virulence, and selective inhibition of FXII may improve the host response to pathogens.
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Affiliation(s)
- C Puy
- Department of Biomedical Engineering, Oregon Health & Science University, Portland, OR, USA.
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Bhattacharjee G, Revenko AS, Crosby JR, May C, Gao D, Zhao C, Monia BP, MacLeod AR. Inhibition of vascular permeability by antisense-mediated inhibition of plasma kallikrein and coagulation factor 12. Nucleic Acid Ther 2013; 23:175-87. [PMID: 23582057 DOI: 10.1089/nat.2013.0417] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Hereditary angioedema (HAE) is a rare disorder characterized by recurrent, acute, and painful episodes of swelling involving multiple tissues. Deficiency or malfunction of the serine protease inhibitor C1 esterase inhibitor (C1-INH) results in HAE types 1 and 2, respectively, whereas mutations in coagulation factor 12 (f12) have been associated with HAE type 3. C1-INH is the primary inhibitor of multiple plasma cascade pathways known to be altered in HAE patients, including the complement, fibrinolytic, coagulation, and kinin-kallikrein pathways. We have selectively inhibited several components of both the kinin-kallikrein system and the coagulation cascades with potent and selective antisense oligonucleotides (ASOs) to investigate their relative contributions to vascular permeability. We have also developed ASO inhibitors of C1-INH and characterized their effects on vascular permeability in mice as an inducible model of HAE. Our studies demonstrate that ASO-mediated reduction in C1-INH plasma levels results in increased vascular permeability and that inhibition of proteases of the kinin-kallikrein system, either f12 or prekallikrein (PKK) reverse the effects of C1-INH depletion with similar effects on both basal and angiotensin converting enzyme (ACE) inhibitor-induced permeability. In contrast, inhibition of coagulation factors 11 (f11) or 7 (f7) had no effect. These results suggest that the vascular defects observed in C1-INH deficiency are dependent on the kinin-kallikrein system proteases f12 and PKK, and not mediated through the coagulation pathways. In addition, our results highlight a novel therapeutic modality that can potentially be employed prophylactically to prevent attacks in HAE patients.
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Affiliation(s)
- Gourab Bhattacharjee
- Department of Antisense Drug Discovery, Isis Pharmaceuticals, Carlsbad, California 92010, USA.
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de Maat S, van Dooremalen S, de Groot PG, Maas C. A nanobody-based method for tracking factor XII activation in plasma. Thromb Haemost 2013; 110:458-68. [PMID: 23349032 DOI: 10.1160/th12-11-0792] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2012] [Accepted: 12/15/2012] [Indexed: 11/05/2022]
Abstract
The physiological role of the plasma protein factor XII (FXII), as well as its involvement in human pathology, is poorly understood. While FXII is implicated in thrombotic pathology as a coagulation factor, it can contribute to inflammatory conditions without triggering coagulation. We recently generated nanobodies against the catalytic domain of activated FXII (FXIIa). Here, we describe two of these nanobodies, A10 and B7, both of which do not recognise FXII. Nanobody A10 recognises the catalytic domain of purified α-FXIIa (80 kDa), but not that of purified β-FXIIa (28 kDa), whereas nanobody B7 recognises both. This suggests minute differences in the catalytic domain between these isoforms of FXIIa. The detection of FXIIa by these nanobodies in plasma can become compromised through inactivation by serine protease inhibitors. This effect can be efficiently countered through the addition of the small-molecular protease inhibitor PPACK. Finally, we show that our nanobody-based assays in vitro distinguish various activation products of FXII that differ with the type of activator present: whereas procoagulant activators solely trigger the formation of a species that is captured by B7, proinflammatory activators first generate a species that is recognised by B7, which is later converted into a species that is recognised by A10. These findings suggest that a progressive proteolysis of FXIIa results in the generation a non-procoagulant form of FXIIa, whereas retention of intermediate forms triggers coagulation. Moreover, our findings indicate the development of nanobodies against activated enzymes offers improved opportunities to investigate their contribution to health and disease.
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Affiliation(s)
- S de Maat
- Dr. C. Maas, University Medical Center Utrecht, Department of Clinical Chemistry and Hematology, Room G.03.550, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands, Tel.: +31 88 755 6513, Fax: +31 88 755 5418, E-mail:
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Siegerink B, Rosendaal FR, Algra A. High-molecular-weight kininogen and the risk of a myocardial infarction and ischemic stroke in young women: the RATIO case-control study. J Thromb Haemost 2012; 10:2409-12. [PMID: 22978483 DOI: 10.1111/j.1538-7836.2012.04927.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- B Siegerink
- Department of Clinical Epidemiology, Leiden University Medical Center, Leiden Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center, Leiden Department of Thrombosis and Haemostasis, Leiden University Medical Center, Leiden UMC Utrecht Stroke Center, Department of Neurology and Neurosurgery, University Medical Center, Utrecht Julius Center, University Medical Center, Utrecht, the Netherlands
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Abstract
Coagulation factor XII (FXII, Hageman factor, EC = 3.4.21.38) is the zymogen of the serine protease, factor XIIa (FXIIa). FXII is converted to FXIIa through autoactivation induced by "contact" to charged surfaces. FXIIa is of crucial importance for fibrin formation in vitro, but deficiency in the protease is not associated with excessive bleeding. For decades, FXII was considered to have no function for coagulation in vivo. Our laboratory developed the first murine knockout model of FXII. Consistent with their human counterparts, FXII(-/-) mice have a normal hemostatic capacity. However, thrombus formation in FXII(-/-) mice is largely defective, and the animals are protected from experimental cerebral ischemia and pulmonary embolism. This murine model has created new interest in FXII because it raises the possibility for safe anticoagulation, which targets thrombosis without influence on hemostasis. We recently have identified platelet polyphosphate (an inorganic polymer) and mast cell heparin as in vivo FXII activators with implications on the initiation of thrombosis and edema during hypersensitivity reactions. Independent of its protease activity, FXII exerts mitogenic activity with implications for angiogenesis. The goal of this review is to summarize the in vivo functions of FXII, with special focus to its functions in thrombosis and vascular biology.
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Affiliation(s)
- S Shapiro
- Centre for Haematology, Imperial College, Hammersmith Hospital, London, UK.
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Lippi G, Favaloro EJ, Franchini M. Paradoxical thrombosis part 1: factor replacement therapy, inherited clotting factor deficiencies and prolonged APTT. J Thromb Thrombolysis 2012; 34:360-6. [DOI: 10.1007/s11239-012-0753-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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Kluft C, Burggraaf J. Introduction to haemostasis from a pharmacodynamic perspective. Br J Clin Pharmacol 2012; 72:538-46. [PMID: 21342216 DOI: 10.1111/j.1365-2125.2011.03946.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Biochemical characterization of the haemostatic system has advanced significantly in the past decades. Sub-systems, such as coagulation, fibrinolysis, blood cells and platelets and the vessel wall have been studied by specialists, mostly separately and independently. The time has come to integrate the approaches, and, in particular, to develop tests to document the state of the whole system and to have available adequate pharmacodynamic tests to evaluate treatments. Many examples are available to show that traditional general methods of clotting and lysis do not provide the information that is desired. The present tendency is to use specific methods for specific factors or effects which are very limited in pharmacological information. There is also increasing awareness of the occurrence of rather broad interindividual variability in the haemostatic system. This suggests that individually tailored treatments are required. This is the more relevant since haemostasis is a balance and treatment should be positioned between efficacy and safety. The conclusion is reached that there is a need for integrated or global methods or sets of methods that reflect the complexity and individual status appropriately and allow the practitioner to judge the effects of interventions and their individual aspects.
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Affiliation(s)
- Cornelis Kluft
- Centre of Human Drug Research, Zernikedreef 10, 2333 CL, Leiden, The Netherlands.
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Cei M, Mumoli N, Giuntoli S, Marino O, Pasquinelli P, Taddei P, Mandolesi C, Genovesi Ebert A. Concomitant ST-elevation myocardial infarction and deep vein thrombosis in a patient with severe factor XII deficiency: case report and review of the literature. QJM 2011; 104:1083-6. [PMID: 21106502 DOI: 10.1093/qjmed/hcq221] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- M Cei
- Department of Internal, Medicine, Ospedale Civile Livorno, viale Alfieri 36, 57124 Livorno, Italy.
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Factor XIIa regulates the structure of the fibrin clot independently of thrombin generation through direct interaction with fibrin. Blood 2011; 118:3942-51. [DOI: 10.1182/blood-2011-03-339572] [Citation(s) in RCA: 103] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Abstract
Recent data indicate an important contribution of coagulation factor (F)XII to in vivo thrombus formation. Because fibrin structure plays a key role in clot stability and thrombosis, we hypothesized that FXII(a) interacts with fibrin(ogen) and thereby regulates clot structure and function. In plasma and purified system, we observed a dose-dependent increase in fibrin fiber density and decrease in turbidity, reflecting a denser structure, and a nonlinear increase in clot stiffness with FXIIa. In plasma, this increase was partly independent of thrombin generation, as shown in clots made in prothrombin-deficient plasma initiated with snake venom enzyme and in clots made from plasma deficient in FXII and prothrombin. Purified FXII and α-FXIIa, but not β-FXIIa, bound to purified fibrinogen and fibrin with nanomolar affinity. Immunostaining of human carotid artery thrombi showed that FXII colocalized with areas of dense fibrin deposition, providing evidence for the in vivo modulation of fibrin structure by FXIIa. These data demonstrate that FXIIa modulates fibrin clot structure independently of thrombin generation through direct binding of the N-terminus of FXIIa to fibrin(ogen). Modification of fibrin structure by FXIIa represents a novel physiologic role for the contact pathway that may contribute to the pathophysiology of thrombosis.
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