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Blood Apr 2023
Topics: Antithrombins; Factor IXa; Antithrombin III; Anticoagulants
PubMed: 37079331
DOI: 10.1182/blood.2023019793 -
Blood Jul 2022
Topics: Antithrombin III; Antithrombin III Deficiency; Antithrombins; Glycosylation; Humans; Sugars; Thrombophilia
PubMed: 35834281
DOI: 10.1182/blood.2022016677 -
The Journal of Surgical Research Dec 2020Antithrombin deficiency (ATD) was described in 1965 by Olav Egeberg as the first known inherited form of thrombophilia. Today, it is understood that ATDs can be... (Review)
Review
Antithrombin deficiency (ATD) was described in 1965 by Olav Egeberg as the first known inherited form of thrombophilia. Today, it is understood that ATDs can be congenital or acquired, leading to qualitative, quantitative, or mixed abnormalities in antithrombin (AT). All ATDs ultimately hinder AT's ability to serve as an endogenous anticoagulant and antiinflammatory agent. As a result, ATD patients possess higher risk for thromboembolism and can develop recurrent venous and arterial thromboses. Because heparin relies on AT to augment its physiologic function, patients with ATD often exhibit profound heparin resistance. Although rare as a genetic disorder, acquired forms of ATD are seen with surprising frequency in critically ill patients. This review discusses ATD in the context of surgical critical care with specific relevance to trauma, thermal burns, cardiothoracic surgery, and sepsis.
Topics: Administration, Oral; Anticoagulants; Antithrombin III; Antithrombin III Deficiency; Antithrombins; Critical Care; Critical Illness; Heparin; Humans; Mutation; Postoperative Complications; Recombinant Proteins; Sepsis; Surgical Procedures, Operative; Thrombomodulin; Thrombosis; Wounds and Injuries
PubMed: 32799002
DOI: 10.1016/j.jss.2020.07.010 -
Journal of Thrombosis and Haemostasis :... Dec 2020Antithrombin (AT) is a major plasma glycoprotein of the serpin superfamily that regulates the proteolytic activity of the procoagulant proteases of both intrinsic and... (Review)
Review
Antithrombin (AT) is a major plasma glycoprotein of the serpin superfamily that regulates the proteolytic activity of the procoagulant proteases of both intrinsic and extrinsic pathways. Two important structural features that participate in the regulatory function of AT include a mobile reactive center loop that binds to active site of coagulation proteases, trapping them in the form of inactive covalent complexes, and a basic D-helix that binds to therapeutic heparins and heparan sulfate proteoglycans (HSPGs) on vascular endothelial cells. The binding of D-helix of AT by therapeutic heparins promotes the reactivity of the serpin with coagulation proteases by several orders of magnitude by both a conformational activation of the serpin and a template (bridging) mechanism. In addition to its essential anticoagulant function, AT elicits a potent anti-inflammatory signaling response when it binds to distinct vascular endothelial cell HSPGs, thereby inducing prostacyclin synthesis. Syndecans-4 has been found as a specific membrane-bound HSPG receptor on endothelial cells that relays the signaling effect of AT to the relevant second messenger molecules in the signal transduction pathways inside the cell. However, following cleavage by coagulation proteases and/or by spontaneous conversion to a latent form, AT loses both its anti-inflammatory activity and high-affinity interaction with heparin and HSPGs. Interestingly, these low-affinity heparin conformers of AT elicit potent proapoptotic and antiangiogenic activities by also binding to specific HSPGs by unknown mechanisms. This review article will summarize current knowledge about mechanisms through which different conformers of AT exert their serine protease inhibitory and intracellular signaling functions in these biological pathways.
Topics: Anticoagulants; Antithrombin III; Antithrombins; Endothelial Cells; Heparin; Signal Transduction
PubMed: 32780936
DOI: 10.1111/jth.15052 -
Clinical and Applied... 2023Antithrombin (AT) is a natural anticoagulant pivotal in inactivating serine protease enzymes in the coagulation cascade, making it a potent inhibitor of blood clot...
Antithrombin (AT) is a natural anticoagulant pivotal in inactivating serine protease enzymes in the coagulation cascade, making it a potent inhibitor of blood clot formation. AT also possesses anti-inflammatory properties by influencing anticoagulation and directly interacting with endothelial cells. Hereditary AT deficiency is one of the most severe inherited thrombophilias, with up to 85% lifetime risk of venous thromboembolism. Acquired AT deficiency arises during heparin therapy or states of hypercoagulability like sepsis and premature infancy. Optimization of AT levels in individuals with AT deficiency is an important treatment consideration, particularly during high-risk situations such as surgery, trauma, pregnancy, and postpartum. Here, we integrate the existing evidence surrounding the approved uses of AT therapy, as well as potential additional patient populations where AT therapy has been considered by the medical community, including any available consensus statements and guidelines. We also describe current knowledge regarding cost-effectiveness of AT concentrate in different contexts. Future work should seek to identify specific patient populations for whom targeted AT therapy is likely to provide the strongest clinical benefit.
Topics: Pregnancy; Female; Humans; Antithrombins; Endothelial Cells; Anticoagulants; Antithrombin III; Blood Coagulation; Antithrombin III Deficiency
PubMed: 37822179
DOI: 10.1177/10760296231205279 -
International Journal of Molecular... Oct 2022Recent research has contributed significantly to our understanding of the pathogenesis of acute disseminated intravascular coagulation. COVID-19 can be considered as a... (Review)
Review
Antithrombin as Therapeutic Intervention against Sepsis-Induced Coagulopathy and Disseminated Intravascular Coagulation: Lessons Learned from COVID-19-Associated Coagulopathy.
Recent research has contributed significantly to our understanding of the pathogenesis of acute disseminated intravascular coagulation. COVID-19 can be considered as a new underlying condition of disseminated intravascular coagulation. In this narrative review, current evidence is presented regarding biomarker differences between sepsis-induced and COVID-19-associated coagulopathies, supporting the importance of acquired antithrombin deficiency in the early differential diagnosis of septic coagulopathy and its potential impact on treatment with endogenous anticoagulants. Establishing new scoring systems for septic coagulopathy in combination with endogenous anticoagulant biomarker activities may allow for the identification of those in the heterogeneous population of sepsis patients who are more likely to benefit from targeted specific treatment interventions.
Topics: Humans; Disseminated Intravascular Coagulation; Antithrombins; COVID-19; Anticoagulants; Blood Coagulation Disorders; Sepsis; Antithrombin III; Biomarkers
PubMed: 36293332
DOI: 10.3390/ijms232012474 -
British Medical Bulletin May 1978
Review
Topics: Antithrombin III; Antithrombins; Blood Coagulation; Blood Coagulation Factors; Chemical Fractionation; Chemical Phenomena; Chemistry; Factor X; Heparin; Humans; Kinetics; Thrombin; Thrombosis
PubMed: 350337
DOI: 10.1093/oxfordjournals.bmb.a071484 -
Blood Coagulation & Fibrinolysis : An... Mar 2024Antithrombin is an essential protein that acts as a natural anticoagulant in the human body. It is synthesized by the liver and belongs to the serine protease... (Review)
Review
Antithrombin is an essential protein that acts as a natural anticoagulant in the human body. It is synthesized by the liver and belongs to the serine protease inhibitors, which are commonly referred to as the SERPINS superfamily. The antithrombin molecule comprises 432 amino acids and has a molecular weight of approximately 58 200 D. It consists of three domains, including an amino-terminal domain, a carbohydrate-rich domain, and a carboxyl-terminal domain. The amino-terminal domain binds with heparin, whereas the carboxyl-terminal domain binds with serine protease. Antithrombin is a crucial natural anticoagulant that contributes approximately 60-80% of plasma anticoagulant activities in the human body. Moreover, antithrombin has anti-inflammatory effects that can be divided into coagulation-dependent and coagulation-independent effects. Furthermore, it exhibits antitumor activity and possesses a broad range of antiviral properties. Inherited type I antithrombin deficiency is a quantitative disorder that is characterized by low antithrombin activity due to low plasma levels. On the other hand, inherited type II antithrombin deficiency is a qualitative disorder that is characterized by defects in the antithrombin molecule. Acquired antithrombin deficiencies are more common than hereditary deficiencies and are associated with various clinical conditions due to reduced synthesis, increased loss, or enhanced consumption. The purpose of this review was to provide an update on the structure, functions, clinical implications, and methods of detection of antithrombin.
Topics: Humans; Antithrombins; Antithrombin III; Anticoagulants; Heparin; Blood Coagulation; Antithrombin III Deficiency
PubMed: 38179715
DOI: 10.1097/MBC.0000000000001271 -
Pediatric Critical Care Medicine : a... Aug 2020Antithrombin is a cofactor in the coagulation cascade with mild anticoagulant activity and facilitates the action of heparin as an anticoagulant. Antithrombin...
OBJECTIVES
Antithrombin is a cofactor in the coagulation cascade with mild anticoagulant activity and facilitates the action of heparin as an anticoagulant. Antithrombin concentrate dosing guidelines vary but most commonly suggest that each unit of antithrombin concentrate per body weight increases the plasma antithrombin level by 1.5% to 2.2% (depending on manufacturer). We aimed to establish a dosing recommendation dependent on age and disease state.
DESIGN
A retrospective analysis of all antithrombin concentrate doses over a period of 5 years. We calculated the increase any respective antithrombin concentrate dose achieved, indexed by body weight, and performed a multivariable analysis to establish independent factors associated with the effectiveness of antithrombin concentrate.
SETTING
A PICU at a university-affiliated children's hospital.
PATIENTS
One hundred fifty-five patients treated in a PICU.
INTERVENTIONS
None.
MEASUREMENTS AND MAIN RESULTS
The effect of 562 doses of antithrombin concentrate on plasma antithrombin levels administered to 155 patients, of which 414 (73.7%) antithrombin concentrate doses administered during extracorporeal life support treatment, were analyzed. For all patients, each unit of antithrombin concentrate/kg increased plasma antithrombin level by 0.86% (SD 0.47%). Plasma antithrombin level increase was influenced by body weight (increase of 0.76% [interquartile range, 0.6-0.92%] for patients < 5 kg; 1.38% [interquartile range, 1.11-2.10%] for > 20 kg), disease state (liver failure having the poorest antithrombin increase) and whether patients were treated with extracorporeal circulatory support (less antithrombin increase on extracorporeal life support). Heparin dose at the time of administration did not influence with amount of change in antithrombin level.
CONCLUSIONS
Current antithrombin concentrate dosing guidelines overestimate the effect on plasma antithrombin level in critically ill children. Current recommendations result in under-dosing of antithrombin concentrate administration. Age, disease state, and extracorporeal life support should be taken into consideration when administering antithrombin concentrate.
Topics: Anticoagulants; Antithrombin III; Antithrombins; Child; Heparin; Humans; Plasma; Retrospective Studies
PubMed: 32452976
DOI: 10.1097/PCC.0000000000002383 -
Intensive Care Medicine Apr 2016Antithrombin III (AT III) is an anticoagulant with anti-inflammatory properties. We assessed the benefits and harms of AT III in critically ill patients. (Meta-Analysis)
Meta-Analysis Review
PURPOSE
Antithrombin III (AT III) is an anticoagulant with anti-inflammatory properties. We assessed the benefits and harms of AT III in critically ill patients.
METHODS
We searched from inception to 27 August 2015 in CENTRAL, MEDLINE, EMBASE, CAB, BIOSIS and CINAHL. We included randomized controlled trials (RCTs) irrespective of publication status, date of publication, blinding status, outcomes published or language.
RESULTS
We included 30 RCTs with a total of 3933 participants. The majority of included trials were at high risk of bias. Combining all trials, regardless of bias, showed no statistically significant effect of AT III on mortality (RR 0.95, 95% CI 0.88-1.03, I (2) = 0%, fixed-effect model, 29 trials, 3882 participants). Among those with severe sepsis and disseminated intravascular coagulation (DIC), AT III showed no impact on mortality (RR 0.95, 95% Cl 0.88-1.03, I (2) = 0%, fixed-effect model, 12 trials, 2858 participants). We carried out multiple subgroup and sensitivity analyses to assess the benefits and harms of AT III and to examine the impact of risk of bias. AT III significantly increased bleeding events (RR 1.58, 95% CI 1.35-1.84, I (2) = 0%, fixed-effect model, 11 trials, 3019 participants). However, for all other outcome measures and analyses, the results did not reach statistical significance.
CONCLUSIONS
There is insufficient evidence to support AT III substitution in any category of critically ill participants including those with sepsis and DIC. AT III did not show an impact on mortality, but increased the risk of bleeding.
Topics: Antithrombin III; Antithrombins; Critical Illness; Disseminated Intravascular Coagulation; Humans; Randomized Controlled Trials as Topic; Sepsis
PubMed: 26862016
DOI: 10.1007/s00134-016-4225-7