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International Journal of Molecular... Feb 2022Severe inherited thrombophilia includes rare deficiencies of natural anticoagulants (antithrombin and proteins C and S) and homozygous or combined factor V Leiden and... (Review)
Review
Severe inherited thrombophilia includes rare deficiencies of natural anticoagulants (antithrombin and proteins C and S) and homozygous or combined factor V Leiden and FII G20210A variants. They are associated with a high thrombosis risk and can impact the duration of anticoagulation therapy for patients with a venous thromboembolism (VTE) event. Therefore, it is important to diagnose thrombophilia and to use adapted anticoagulant therapy. The widespread use of direct anticoagulants (DOACs) for VTE has raised new issues concerning inherited thrombophilia. Concerning inherited thrombophilia diagnosis, DOACs are directed toward either FIIa or FXa and can therefore interfere with coagulation assays. This paper reports DOAC interference in several thrombophilia tests, including the assessment of antithrombin, protein S, and protein C activities. Antithrombin activity and clot-based assays used for proteins C and S can be overestimated, with a risk of missing a deficiency. The use of a device to remove DOACs should be considered to minimize the risk of false-negative results. The place of DOACs in the treatment of VTE in thrombophilia patients is also discussed. Available data are encouraging, but given the variability in thrombosis risk within natural anticoagulant deficiencies, evidence in patients with well-characterized thrombophilia would be useful.
Topics: Administration, Oral; Anticoagulants; Antithrombins; Humans; Protein C; Risk Factors; Thrombophilia; Thrombosis; Venous Thromboembolism
PubMed: 35163742
DOI: 10.3390/ijms23031821 -
Blood Advances Nov 2023Hereditary and acquired thrombophilia are risk factors for venous thromboembolism (VTE). Whether testing helps guide management decisions is controversial. These...
Hereditary and acquired thrombophilia are risk factors for venous thromboembolism (VTE). Whether testing helps guide management decisions is controversial. These evidence-based guidelines from the American Society of Hematology (ASH) intend to support decision making about thrombophilia testing. ASH formed a multidisciplinary guideline panel covering clinical and methodological expertise and minimizing bias from conflicts of interest. The McMaster University GRADE Centre provided logistical support, performed systematic reviews, and created evidence profiles and evidence-to-decision tables. The Grading of Recommendations Assessment, Development, and Evaluation approach (GRADE) was used. Recommendations were subject to public comment. The panel agreed on 23 recommendations regarding thrombophilia testing and associated management. Nearly all recommendations are based on very low certainty in the evidence due to modeling assumptions. The panel issued a strong recommendation against testing the general population before starting combined oral contraceptives (COCs) and conditional recommendations for thrombophilia testing in the following scenarios: (a) patients with VTE associated with nonsurgical major transient or hormonal risk factors; (b) patients with cerebral or splanchnic venous thrombosis, in settings where anticoagulation would otherwise be discontinued; (c) individuals with a family history of antithrombin, protein C, or protein S deficiency when considering thromboprophylaxis for minor provoking risk factors and for guidance to avoid COCs/hormone replacement therapy; (d) pregnant women with a family history of high-risk thrombophilia types; and (e) patients with cancer at low or intermediate risk of thrombosis and with a family history of VTE. For all other questions, the panel provided conditional recommendations against testing for thrombophilia.
Topics: Humans; Female; Pregnancy; United States; Anticoagulants; Venous Thromboembolism; Thrombophilia; Antithrombins; Hematology
PubMed: 37195076
DOI: 10.1182/bloodadvances.2023010177 -
Cardiovascular Drugs and Therapy Aug 2020Ischaemic stroke and systemic embolism are the major potentially preventable complications of atrial fibrillation (AF) leading to severe morbidity and mortality.... (Review)
Review
Ischaemic stroke and systemic embolism are the major potentially preventable complications of atrial fibrillation (AF) leading to severe morbidity and mortality. Anticoagulation using vitamin K antagonists (VKA) or non-vitamin K oral anticoagulants (NOACs) is mandatory for stroke prevention in AF. Following approval of the four NOACs dabigatran, rivaroxaban, apixaban, and edoxaban, the use of VKA is declining steadily. Increasing age with thresholds of 65 and 75 years is a strong risk factor when determining annual stroke risk in AF patients. Current recommendations such as the "2016 Guidelines for the management of atrial fibrillation" of the European Society of Cardiology and the "2019 AHA/ACC/HRS Focused Update" by the American College of Cardiology, the American Heart Association, and the Heart Rhythm Society strengthen the importance of anticoagulation and detection of bleeding risks, of which older age is an important one. While patients aged ≥ 75 years are usually underrepresented in randomised clinical trials, they represent almost 40% of the trial populations in the large NOAC approval studies. Therefore, a sufficient amount of data is available to assess the efficacy and safety for this patient cohort in that specific indication. In this article, the evidence for stroke prevention in AF using either VKA or NOACs is summarised with a special focus on efficacy compared to bleeding risk in patients aged ≥ 75 years. Specifically, we used a model of increased weighing of intracranial bleeding to illustrate the potential benefit of NOACs over VKA in the elderly population. In brief, there are at least two tested strategies with apixaban and edoxaban which even confer an additional clinical net benefit compared with VKA. Furthermore, elderly subgroups of trials for combined antithrombotic treatment following percutaneous coronary interventions in anticoagulated patients are analysed.
Topics: Administration, Oral; Age Factors; Aged; Aged, 80 and over; Anticoagulants; Antithrombins; Atrial Fibrillation; Dabigatran; Factor Xa Inhibitors; Female; Humans; Intracranial Hemorrhages; Male; Pyrazoles; Pyridines; Pyridones; Risk Factors; Rivaroxaban; Stroke; Thiazoles; Treatment Outcome; Vitamin K; Warfarin
PubMed: 32350792
DOI: 10.1007/s10557-020-06981-3 -
Critical Care (London, England) Jan 2020During extracorporeal membrane oxygenation (ECMO), a delicate balance is required to titrate systemic anticoagulation to prevent thrombotic complications within the... (Review)
Review
During extracorporeal membrane oxygenation (ECMO), a delicate balance is required to titrate systemic anticoagulation to prevent thrombotic complications within the circuit and prevent bleeding in the patient. Despite focused efforts to achieve this balance, the frequency of both thrombotic and bleeding events remains high. Anticoagulation is complicated to manage in this population due to the complexities of the hemostatic system that are compounded by age-related developmental hemostatic changes, variable effects of the etiology of critical illness on hemostasis, and blood-circuit interaction. Lack of high-quality data to guide anticoagulation management in ECMO patients results in marked practice variability among centers. One aspect of anticoagulation therapy that is particularly challenging is the use of antithrombin (AT) supplementation for heparin resistance. This is especially controversial in the neonatal and pediatric population due to the baseline higher risk of bleeding in this cohort. The indication for AT supplementation is further compounded by the potential inaccuracy of the diagnosis of heparin resistance based on the standard laboratory parameters used to assess heparin effect. With concerns regarding the adverse impact of bleeding and thrombosis, clinicians and institutions are faced with making difficult, real-time decisions aimed at optimizing anticoagulation in this setting. In this clinically focused review, the authors discuss the complexities of anticoagulation monitoring and therapeutic intervention for patients on ECMO and examine the challenges surrounding AT supplementation given both the historical and current perspectives summarized in the literature on these topics.
Topics: Anticoagulants; Antithrombins; Blood Coagulation; Child; Extracorporeal Membrane Oxygenation; Factor Xa Inhibitors; Female; Hemostatics; Humans; Male; Monitoring, Physiologic; Partial Thromboplastin Time; Whole Blood Coagulation Time
PubMed: 31959232
DOI: 10.1186/s13054-020-2726-9 -
Science Advances Jan 2022Hemophilia is a hereditary disease that remains incurable. Although innovative treatments such as gene therapy or bispecific antibody therapy have been introduced,...
Hemophilia is a hereditary disease that remains incurable. Although innovative treatments such as gene therapy or bispecific antibody therapy have been introduced, substantial unmet needs still exist with respect to achieving long-lasting therapeutic effects and treatment options for inhibitor patients. Antithrombin (AT), an endogenous negative regulator of thrombin generation, is a potent genome editing target for sustainable treatment of patients with hemophilia A and B. In this study, we developed and optimized lipid nanoparticles (LNPs) to deliver Cas9 mRNA along with single guide RNA that targeted AT in the mouse liver. The LNP-mediated CRISPR-Cas9 delivery resulted in the inhibition of AT that led to improvement in thrombin generation. Bleeding-associated phenotypes were recovered in both hemophilia A and B mice. No active off-targets, liver-induced toxicity, and substantial anti-Cas9 immune responses were detected, indicating that the LNP-mediated CRISPR-Cas9 delivery was a safe and efficient approach for hemophilia therapy.
Topics: Animals; Antithrombins; CRISPR-Cas Systems; Gene Editing; Hemophilia A; Humans; Liposomes; Mice; Nanoparticles; Thrombin
PubMed: 35061543
DOI: 10.1126/sciadv.abj6901 -
JAMA Neurology Dec 2019Patients with cerebral venous thrombosis (CVT) are at risk of recurrent venous thrombotic events (VTEs). Non-vitamin K oral anticoagulants have not been evaluated in... (Comparative Study)
Comparative Study Randomized Controlled Trial
IMPORTANCE
Patients with cerebral venous thrombosis (CVT) are at risk of recurrent venous thrombotic events (VTEs). Non-vitamin K oral anticoagulants have not been evaluated in randomized controlled trials in CVT.
OBJECTIVE
To compare the efficacy and safety of dabigatran etexilate with those of dose-adjusted warfarin in preventing recurrent VTEs in patients who have experienced a CVT.
DESIGN, SETTING, AND PARTICIPANTS
RE-SPECT CVT is an exploratory, prospective, randomized (1:1), parallel-group, open-label, multicenter clinical trial with blinded end-point adjudication (PROBE design). It was performed from December 21, 2016, to June 22, 2018, with a follow-up of 25 weeks, at 51 tertiary sites in 9 countries (France, Germany, India, Italy, the Netherlands, Poland, Portugal, Russia, and Spain). Adult consecutive patients with acute CVT, who were stable after 5 to 15 days of treatment with parenteral heparin, were screened for eligibility. Patients with CVT associated with central nervous system infection or major trauma were excluded, but those with intracranial hemorrhage from index CVT were allowed to participate. After exclusions, 120 patients were randomized. Data were analyzed following the intention-to-treat approach.
INTERVENTIONS
Dabigatran, 150 mg twice daily, or dose-adjusted warfarin for a treatment period of 24 weeks.
MAIN OUTCOMES AND MEASURES
Primary outcome was a composite of patients with a new VTE (recurrent CVT, deep vein thrombosis of any limb, pulmonary embolism, and splanchnic vein thrombosis) or major bleeding during the study period. Secondary outcomes were cerebral venous recanalization and clinically relevant non-major bleeding events.
RESULTS
In total, 120 patients with CVT were randomized to the 2 treatment groups (60 to dabigatran and 60 to dose-adjusted warfarin). Of the randomized patients, the mean (SD) age was 45.2 (13.8) years, and 66 (55.0%) were women. The mean (SD) duration of exposure was 22.3 (6.16) weeks for the dabigatran group and 23.0 (5.20) weeks for the warfarin group. No recurrent VTEs were observed. One (1.7%; 95% CI, 0.0-8.9) major bleeding event (intestinal) was recorded in the dabigatran group, and 2 (3.3%; 95% CI, 0.4-11.5) (intracranial) in the warfarin group. One additional patient (1.7; 95% CI, 0.0-8.9) in the warfarin group experienced a clinically relevant non-major bleeding event. Recanalization occurred in 33 patients in the dabigatran group (60.0%; 95% CI, 45.9-73.0) and in 35 patients in the warfarin group (67.3%; 95% CI, 52.9-79.7).
CONCLUSIONS AND RELEVANCE
This trial found that patients who had CVT anticoagulated with either dabigatran or warfarin had low risk of recurrent VTEs, and the risk of bleeding was similar with both medications, suggesting that both dabigatran and warfarin may be safe and effective for preventing recurrent VTEs in patients with CVT.
TRIAL REGISTRATION
ClinicalTrials.gov identifier: NCT02913326.
Topics: Adult; Aged; Anticoagulants; Antithrombins; Dabigatran; Female; Follow-Up Studies; Hemorrhage; Humans; Intracranial Thrombosis; Male; Middle Aged; Prospective Studies; Single-Blind Method; Treatment Outcome; Venous Thrombosis; Warfarin
PubMed: 31479105
DOI: 10.1001/jamaneurol.2019.2764 -
The Cochrane Database of Systematic... Apr 2023Deep vein thrombosis (DVT) is a condition in which a clot forms in the deep veins, most commonly of the leg. It occurs in approximately one in 1000 people. If left... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Deep vein thrombosis (DVT) is a condition in which a clot forms in the deep veins, most commonly of the leg. It occurs in approximately one in 1000 people. If left untreated, the clot can travel up to the lungs and cause a potentially life-threatening pulmonary embolism (PE). Previously, a DVT was treated with the anticoagulants heparin and vitamin K antagonists. However, two forms of direct oral anticoagulants (DOACs) have been developed: oral direct thrombin inhibitors (DTIs) and oral factor Xa inhibitors, which have characteristics that may be favourable compared to conventional treatment, including oral administration, a predictable effect, lack of frequent monitoring or dose adjustment and few known drug interactions. DOACs are now commonly being used for treating DVT: recent guidelines recommended DOACs over conventional anticoagulants for both DVT and PE treatment. This Cochrane Review was first published in 2015. It was the first systematic review to measure the effectiveness and safety of these drugs in the treatment of DVT. This is an update of the 2015 review. OBJECTIVES: To assess the effectiveness and safety of oral DTIs and oral factor Xa inhibitors versus conventional anticoagulants for the long-term treatment of DVT.
SEARCH METHODS
The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase and CINAHL databases and the World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers to 1 March 2022.
SELECTION CRITERIA
We included randomised controlled trials (RCTs) in which people with a DVT, confirmed by standard imaging techniques, were allocated to receive an oral DTI or an oral factor Xa inhibitor compared with conventional anticoagulation or compared with each other for the treatment of DVT. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods. Our primary outcomes were recurrent venous thromboembolism (VTE), recurrent DVT and PE. Secondary outcomes included all-cause mortality, major bleeding, post-thrombotic syndrome (PTS) and quality of life (QoL). We used GRADE to assess the certainty of evidence for each outcome.
MAIN RESULTS
We identified 10 new studies with 2950 participants for this update. In total, we included 21 RCTs involving 30,895 participants. Three studies investigated oral DTIs (two dabigatran and one ximelagatran), 17 investigated oral factor Xa inhibitors (eight rivaroxaban, five apixaban and four edoxaban) and one three-arm trial investigated both a DTI (dabigatran) and factor Xa inhibitor (rivaroxaban). Overall, the studies were of good methodological quality. Meta-analysis comparing DTIs to conventional anticoagulation showed no clear difference in the rate of recurrent VTE (odds ratio (OR) 1.17, 95% confidence interval (CI) 0.83 to 1.65; 3 studies, 5994 participants; moderate-certainty evidence), recurrent DVT (OR 1.11, 95% CI 0.74 to 1.66; 3 studies, 5994 participants; moderate-certainty evidence), fatal PE (OR 1.32, 95% CI 0.29 to 6.02; 3 studies, 5994 participants; moderate-certainty evidence), non-fatal PE (OR 1.29, 95% CI 0.64 to 2.59; 3 studies, 5994 participants; moderate-certainty evidence) or all-cause mortality (OR 0.66, 95% CI 0.41 to 1.08; 1 study, 2489 participants; moderate-certainty evidence). DTIs reduced the rate of major bleeding (OR 0.58, 95% CI 0.38 to 0.89; 3 studies, 5994 participants; high-certainty evidence). For oral factor Xa inhibitors compared with conventional anticoagulation, meta-analysis demonstrated no clear difference in recurrent VTE (OR 0.85, 95% CI 0.71 to 1.01; 13 studies, 17,505 participants; moderate-certainty evidence), recurrent DVT (OR 0.70, 95% CI 0.49 to 1.01; 9 studies, 16,439 participants; moderate-certainty evidence), fatal PE (OR 1.18, 95% CI 0.69 to 2.02; 6 studies, 15,082 participants; moderate-certainty evidence), non-fatal PE (OR 0.93, 95% CI 0.68 to 1.27; 7 studies, 15,166 participants; moderate-certainty evidence) or all-cause mortality (OR 0.87, 95% CI 0.67 to 1.14; 9 studies, 10,770 participants; moderate-certainty evidence). Meta-analysis showed a reduced rate of major bleeding with oral factor Xa inhibitors compared with conventional anticoagulation (OR 0.63, 95% CI 0.45 to 0.89; 17 studies, 18,066 participants; high-certainty evidence). AUTHORS' CONCLUSIONS: The current review suggests that DOACs may be superior to conventional therapy in terms of safety (major bleeding), and are probably equivalent in terms of efficacy. There is probably little or no difference between DOACs and conventional anticoagulation in the prevention of recurrent VTE, recurrent DVT, pulmonary embolism and all-cause mortality. DOACs reduced the rate of major bleeding compared to conventional anticoagulation. The certainty of evidence was moderate or high.
Topics: Humans; Anticoagulants; Antithrombins; Factor Xa Inhibitors; Rivaroxaban; Dabigatran; Venous Thromboembolism; Neoplasm Recurrence, Local; Venous Thrombosis; Pulmonary Embolism; Hemorrhage
PubMed: 37058421
DOI: 10.1002/14651858.CD010956.pub3 -
Blood Apr 2023
Topics: Antithrombins; Factor IXa; Antithrombin III; Anticoagulants
PubMed: 37079331
DOI: 10.1182/blood.2023019793 -
International Journal of Molecular... Apr 2021Antithrombin (AT) is a natural anticoagulant that interacts with activated proteases of the coagulation system and with heparan sulfate proteoglycans (HSPG) on the... (Review)
Review
Antithrombin (AT) is a natural anticoagulant that interacts with activated proteases of the coagulation system and with heparan sulfate proteoglycans (HSPG) on the surface of cells. The protein, which is synthesized in the liver, is also essential to confer the effects of therapeutic heparin. However, AT levels drop in systemic inflammatory diseases. The reason for this decline is consumption by the coagulation system but also by immunological processes. Aside from the primarily known anticoagulant effects, AT elicits distinct anti-inflammatory signaling responses. It binds to structures of the glycocalyx (syndecan-4) and further modulates the inflammatory response of endothelial cells and leukocytes by interacting with surface receptors. Additionally, AT exerts direct antimicrobial effects: depending on AT glycosylation it can bind to and perforate bacterial cell walls. Peptide fragments derived from proteolytic degradation of AT exert antibacterial properties. Despite these promising characteristics, therapeutic supplementation in inflammatory conditions has not proven to be effective in randomized control trials. Nevertheless, new insights provided by subgroup analyses and retrospective trials suggest that a recommendation be made to identify the patient population that would benefit most from AT substitution. Recent experiment findings place the role of various AT isoforms in the spotlight. This review provides an overview of new insights into a supposedly well-known molecule.
Topics: Animals; Anti-Inflammatory Agents; Antithrombins; Biomarkers; Disease Management; Disease Resistance; Disease Susceptibility; Host-Pathogen Interactions; Humans; Immunomodulation; Inflammation; Organ Specificity; Signal Transduction
PubMed: 33924175
DOI: 10.3390/ijms22084283 -
Arteriosclerosis, Thrombosis, and... Jul 2023Antithrombin, PC (protein C), and PS (protein S) are circulating natural anticoagulant proteins that regulate hemostasis and of which partial deficiencies are causes of...
BACKGROUND
Antithrombin, PC (protein C), and PS (protein S) are circulating natural anticoagulant proteins that regulate hemostasis and of which partial deficiencies are causes of venous thromboembolism. Previous genetic association studies involving antithrombin, PC, and PS were limited by modest sample sizes or by being restricted to candidate genes. In the setting of the Cohorts for Heart and Aging Research in Genomic Epidemiology consortium, we meta-analyzed across ancestries the results from 10 genome-wide association studies of plasma levels of antithrombin, PC, PS free, and PS total.
METHODS
Study participants were of European and African ancestries, and genotype data were imputed to TOPMed, a dense multiancestry reference panel. Each of the 10 studies conducted a genome-wide association studies for each phenotype and summary results were meta-analyzed, stratified by ancestry. Analysis of antithrombin included 25 243 European ancestry and 2688 African ancestry participants, PC analysis included 16 597 European ancestry and 2688 African ancestry participants, PSF and PST analysis included 4113 and 6409 European ancestry participants. We also conducted transcriptome-wide association analyses and multiphenotype analysis to discover additional associations. Novel genome-wide association studies and transcriptome-wide association analyses findings were validated by in vitro functional experiments. Mendelian randomization was performed to assess the causal relationship between these proteins and cardiovascular outcomes.
RESULTS
Genome-wide association studies meta-analyses identified 4 newly associated loci: 3 with antithrombin levels (, , and ) and 1 with PS levels (-). transcriptome-wide association analyses identified 3 newly associated genes: 1 with antithrombin level (), 1 with PC (), and 1 with PS (). In addition, we replicated 7 independent loci reported in previous studies. Functional experiments provided evidence for the involvement of , , and genes in antithrombin regulation.
CONCLUSIONS
The use of larger sample sizes, diverse populations, and a denser imputation reference panel allowed the detection of 7 novel genomic loci associated with plasma antithrombin, PC, and PS levels.
Topics: Protein C; Protein S; Genome-Wide Association Study; Antithrombins; Transcriptome; Anticoagulants; Antithrombin III; Polymorphism, Single Nucleotide
PubMed: 37128921
DOI: 10.1161/ATVBAHA.122.318213