Cambridge II (A384S) is a highly prevalent antithrombin variant in the British population (1.14 per 1000) and predisposes carriers to a mild but significant increased risk of thrombosis. To determine if the association of Cambridge II with thrombophilia is due to a perturbation of the antithrombin inhibitory mechanism, we expressed and characterized the variant. Antithrombin Cambridge II was found to be normal in its affinity for heparin, its ability to form sodium dodecyl sulfate-stable complexes with factor Xa and thrombin, and its uncatalyzed stoichiometries and rates of inhibition. However, in the presence of full-length heparin there was a 3- and 7-fold increase in stoichiometry of inhibition of factor Xa and thrombin. The stoichiometries were not affected by pentasaccharides, indicating that the inhibitory mechanism of antithrombin Cambridge II is perturbed only in the presence of a bridging glycosaminoglycan. Thus, the vascular localization of antithrombin Cambridge II would render the carrier slightly thrombophilic. The high occurrence of this mutation and its possible propagation from a few founders suggests an evolutionary advantage, perhaps in decreasing postpartum bleeding.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1182/blood-2003-05-1560 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Safety and efficacy of a fitusiran antithrombin-based dose regimen in people with hemophilia A or B: the ATLAS-OLE study.
Blood
March 2025
The National Hemophilia Centre, The Amalia Biron Thrombosis Research Institute, Sheba Medical Centre, Tel Hashomer, Tel Aviv University, Tel Aviv, Tel Aviv, Israel.
Fitusiran, a subcutaneous investigational siRNA therapeutic, lowers antithrombin (AT) to increase thrombin generation and rebalance hemostasis in people with hemophilia. This phase 3 open-label extension study (ATLAS‑OLE, NCT03754790) evaluated safety and efficacy of antithrombin-based dose regimen (AT-DR) in males ≥ 12 years with severe hemophilia A/B, with/without inhibitors. The original 80 mg monthly (QM) dose regimen (ODR) was optimized to AT-DR targeting AT activity levels 15-35% to mitigate thrombotic risk (starting dose 50 mg once every 2 months [Q2M], individually adjusted to 20 mg Q2M or 20/50/80 mg QM as needed).
View Article and Find Full Text PDFAbelacimab versus Rivaroxaban in Patients with Atrial Fibrillation.
N Engl J Med
January 2025
From the TIMI Study Group, Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston (C.T.R., S.M.P., R.P.G., D.A.M., J.F.K., E.L.G., S.A.M., S.D.W., M.S.S.); Anthos Therapeutics, Cambridge, MA (B.H., S.P., D.B.); the Heart Rhythm Center, Taipei Veterans General Hospital and Cardiovascular Center, Taipei, Taiwan (S.-A.C.); Taichung Veterans Hospital, Taichung, Taiwan (S.-A.C.); National Yang Ming Chiao Tung University, Hsinchu, Taiwan (S.-A.C.); National Chung Hsing University, Taichung, Taiwan (S.-A.C.); St. Michael's Hospital, Unity Health Toronto, Peter Munk Cardiac Centre, University Health Network, University of Toronto, Toronto (S.G.G.); Canadian VIGOUR Centre, University of Alberta, Edmonton, Canada (S.G.G.); the Division of Cardiology, Severance Hospital, Yonsei University College of Medicine, Seoul, South Korea (B.J.); the Department of Cardiology, Central Hospital of Northern Pest-Military Hospital, Budapest, Hungary (R.G.K.); the Heart and Vascular Center, Semmelweis University, Budapest, Hungary (R.G.K.); the Internal Cardiology Department, St. Ann University Hospital and Masaryk University, Brno, Czech Republic (J.S.); the Department of Cardiology and Structural Heart Diseases, Medical University of Silesia, Katowice, Poland (W.W.); the Departments of Medicine and of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON, Canada (J.W.); and the Thrombosis and Atherosclerosis Research Institute, Hamilton, ON, Canada (J.W.).
Background: Abelacimab is a fully human monoclonal antibody that binds to the inactive form of factor XI and blocks its activation. The safety of abelacimab as compared with a direct oral anticoagulant in patients with atrial fibrillation is unknown.
Methods: Patients with atrial fibrillation and a moderate-to-high risk of stroke were randomly assigned, in a 1:1:1 ratio, to receive subcutaneous injection of abelacimab (150 mg or 90 mg once monthly) administered in a blinded fashion or oral rivaroxaban (20 mg once daily) administered in an open-label fashion.
Assessment of a next generation sequencing gene panel strategy in 133 patients with negative thrombophilia screening.
J Thromb Haemost
March 2025
C2VN, INSERM, INRAE, Aix Marseille University, Marseille, France; Laboratory of Haematology, La Timone Hospital, Marseille, France. Electronic address:
Background: Although heritability of venous thromboembolism (VTE) is high, the thrombophilia screening appears to be positive only in a minority of VTE patients. Adding rare variants screening to identify VTE missing heritability still requires further assessment.
Objectives: We report the results of a panel strategy after 3 years of application.
Long-term safety and efficacy of fitusiran prophylaxis, and perioperative management, in people with hemophilia A or B.
Blood Adv
March 2025
Division Hematology/Oncology, University of Pittsburgh, Pittsburgh, PA.
Fitusiran is an investigational small interfering RNA therapeutic that targets antithrombin (AT) to rebalance hemostasis in people with hemophilia. Here, we present the results of a completed phase 2 open-label extension study, which evaluated the long-term safety and efficacy of fitusiran in participants with moderate or severe hemophilia A or B, with or without inhibitors. Male participants who had completed the phase 1 study (ClinicalTrials.
View Article and Find Full Text PDFThe common VTE-protective G haplotype of F5 increases factor V-short, TFPI function, and risk of bleeding.
Blood Adv
January 2025
Department of Immunology and Inflammation, Centre for Haematology, Imperial College London, London, United Kingdom.
The G haplotype is a group of co-inherited single nucleotide variants in the F5 gene that reduce venous thromboembolism (VTE) risk. Although 7% of the population is homozygous for the G haplotype (F5-G/G), the underlying mechanism of VTE protection is poorly understood. Using RNA sequencing data from 4651 blood donors in the INTERVAL study, we detected a rare excision event at the factor V (FV)-short splice sites in 5% of F5-G/Gs carriers as compared with 2.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!