scholarly journals Covid-19: AstraZeneca vaccine is not linked to increased risk of blood clots, finds European Medicine Agency

BMJ ◽  
2021 ◽  
pp. n774 ◽  
Author(s):  
Elisabeth Mahase
Keyword(s):  
European Medicine Agency ◽  
Increased Risk ◽  
Blood Clots

scholarly journals Systematic Review of Hormonal Contraception and Risk of Venous Thrombosis

2018 ◽  
Vol 85 (4) ◽  
pp. 470-477 ◽  
Author(s):  
Lynn Keenan ◽  
Tyson Kerr ◽  
Marguerite Duane ◽  
Karl Van Gundy
Keyword(s):  
United States ◽  
Venous Thrombosis ◽  
Ethinyl Estradiol ◽  
Hormonal Contraception ◽  
The United States ◽  
Comparable Efficacy ◽  
Healthy Women ◽  
Increased Risk ◽  
Blood Clots ◽  
The World

Background: Hormonal contraception (HC) is widely used throughout the world and has been associated with venous thrombosis (VT) such as deep vein thrombosis, pulmonary emboli, and cerebral VT. Objectives: To provide a current comprehensive overview of the risk of objectively confirmed VT with HC in healthy women compared to nonusers. Search methods: PubMed was searched from inception to April 2018 for eligible studies in the English language, with hand searching from past systematic reviews. Selection criteria: We selected original research evaluating risk of objectively confirmed VT in healthy women taking oral or nonoral HC compared with nonusers. Data collection: The primary outcome of interest was a fatal or nonfatal VT in users of HC compared to nonusers or past users. Studies with at least twenty events were eligible. Adjusted relative risks with 95 percent confidence intervals were reported. Three independent reviewers extracted data from selected studies. Results: 1,962 publications were retrieved through the search strategy, with 15 publications included. Users of oral contraception with levonorgesterol had increased risk of VT by a range of 2.79–4.07, while other oral hormonal preparations increased risk by 4.0–48.6. Levonorgestrel intrauterine devices did not increase risk. Etonogestrel/ethinyl estradiol vaginal rings increased the risk of VT by 6.5. Norelgestromin/ethinyl estradiol patches increased risk of VT by 7.9. Etonogestrel subcutaneous implants by 1.4 and depot-medroxyprogesterone by 3.6. The risk of fatal VT was increased in women aged fifteen to twenty-four by 18.8-fold. Conclusion: Users of HC have a significant increased risk of VT compared to nonusers. Current risks would project at least 300–400 healthy young women dying yearly in the United States due to HC. Women should be informed of these risks and offered education in fertility-awareness-based methods with comparable efficacy for family planning. Summary: HC is widely used throughout the world and has been associated with blood clots in the legs and lungs. We searched the literature and found the risks of currently used forms of birth control increased between three- and ninefold for blood clots for healthy women. The risks found would project 300–400 women dying from using HC each year in the United States.

Effect of Progesterone and Synthetic Progestins on Whole Blood Clot Formation and Erythrocyte Structure

2017 ◽  
Vol 23 (3) ◽  
pp. 607-617 ◽  
Author(s):  
Albe C. Swanepoel ◽  
Odette Emmerson ◽  
Etheresia Pretorius
Keyword(s):  
Whole Blood ◽  
Blood Clot ◽  
Thrombotic Event ◽  
Clot Formation ◽  
Erythrocyte Aggregation ◽  
Erythrocyte Morphology ◽  
Increased Risk ◽  
Blood Clots ◽  
Membrane Ultrastructure

AbstractCombined oral contraceptive (COC) use is a risk factor for venous thrombosis (VT) and related to the specific type of progestin used. VT is accompanied by inflammation and pathophysiological clot formation, that includes aberrant erythrocytes and fibrin(ogen) interactions. In this paper, we aim to determine the influence of progesterone and different synthetic progestins found in COCs on the viscoelasticity of whole blood clots, as well as erythrocyte morphology and membrane ultrastructure, in an in vitro laboratory study. Thromboelastography (TEG), light microscopy, and scanning electron microscopy were our chosen methods. Our results point out that progestins influence the rate of whole blood clot formation. Alterations to erythrocyte morphology and membrane ultrastructure suggest the presence of eryptosis. We also note increased rouleaux formation, erythrocyte aggregation, and spontaneous fibrin formation in whole blood which may explain the increased risk of VT associated with COC use. Although not all COC users will experience a thrombotic event, individuals with a thrombotic predisposition, due to inflammatory or hematological illness, should be closely monitored to prevent pathological thrombosis.

scholarly journals Potential inheritance patterns of a prothrombin gene mutation in a 23-year-old female and ethical considerations of a positive diagnosis: a case report

2017 ◽  
Vol 5 (1) ◽  
Author(s):  
Hannah Brand
Keyword(s):  
Gene Mutation ◽  
Blood Clot ◽  
Clot Formation ◽  
Ethical Implications ◽  
Increased Risk ◽  
Blood Clots ◽  
History Of ◽  
Prothrombin Gene Mutation ◽  
Prothrombin Gene ◽  
The Individual

Background: Prothrombin, also called Factor II, is a blood clotting protein found in all individuals that is necessary to form blood clots. In most individuals, a balance between bleeding and blood clot formation occurs. However, in individuals with a mutation in the prothrombin gene, the balance is disrupted due to excess production of prothrombin which leads to an increase in blood clot formation (1). Inherited predispositions to blood clot formation are termed hereditary thrombophilia. Prothrombin G20210A mutations are one of the most common hereditary gene associations. Case Description: This report examines the case of a 23-year-old female who has tested positive for the prothrombin gene mutation. The individual has an extensive history of blood clots including 8 deep vein thromboses (DVTs), 4 pulmonary embolisms with one complete infarction, 4 superficial clots, and a miscarried pregnancy attributed to her thrombophilia. The individual has a significant family history of the mutation and takes Coumadin daily for prevention of further clots. Practical and Ethical Implications: Despite a strong familial history of blood clots and related hospitalizations, the parents of the case individual do not want to get their other children tested for the mutation for fear that the children will be denied insurance coverage in their futures. The case individual will likely continue to be on blood thinners indefinitely. This will affect many aspects of her life, including dental treatment, as she will be at an increased risk for bleeding.

scholarly journals Red blood cells modulate structure and dynamics of venous clot formation in sickle cell disease

Blood ◽  
2019 ◽  
Vol 133 (23) ◽  
pp. 2529-2541 ◽  
Author(s):  
Camille Faes ◽  
Anton Ilich ◽  
Amandine Sotiaux ◽  
Erica M. Sparkenbaugh ◽  
Michael W. Henderson ◽  
...  
Keyword(s):  
Venous Thromboembolism ◽  
Sickle Cell Disease ◽  
Plasminogen Activator ◽  
Sickle Cell ◽  
Whole Blood ◽  
Blood Cells ◽  
Cell Disease ◽  
Increased Risk ◽  
Blood Clots ◽  
Tissue Plasminogen

Abstract Sickle cell disease (SCD) is associated with chronic activation of coagulation and an increased risk of venous thromboembolism. Erythrocyte sickling, the primary pathologic event in SCD, results in dramatic morphological changes in red blood cells (RBCs) because of polymerization of the abnormal hemoglobin. We used a mouse model of SCD and blood samples from sickle patients to determine if these changes affect the structure, properties, and dynamics of sickle clot formation. Sickling of RBCs and a significant increase in fibrin deposition were observed in venous thrombi formed in sickle mice. During ex vivo clot contraction, the number of RBCs extruded from sickle whole blood clots was significantly reduced compared with the number released from sickle cell trait and nonsickle clots in both mice and humans. Entrapment of sickled RBCs was largely factor XIIIa–independent and entirely mediated by the platelet-free cellular fraction of sickle blood. Inhibition of phosphatidylserine, but not administration of antisickling compounds, increased the number of RBCs released from sickle clots. Interestingly, whole blood, but not plasma clots from SCD patients, was more resistant to fibrinolysis, indicating that the cellular fraction of blood mediates resistance to tissue plasminogen activator. Sickle trait whole blood clots demonstrated an intermediate phenotype in response to tissue plasminogen activator. RBC exchange in SCD patients had a long-lasting effect on normalizing whole blood clot contraction. Furthermore, RBC exchange transiently reversed resistance of whole blood sickle clots to fibrinolysis, in part by decreasing platelet-derived PAI-1. These properties of sickle clots may explain the increased risk of venous thromboembolism observed in SCD.

scholarly journals COVID-19 susceptibility variants associate with blood clots, thrombophlebitis and circulatory diseases

PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0256988
Author(s):  
Areti Papadopoulou ◽  
Hanan Musa ◽  
Mathura Sivaganesan ◽  
David McCoy ◽  
Panos Deloukas ◽  
...  
Keyword(s):  
Association Studies ◽  
Blood Clot ◽  
Epidemiological Studies ◽  
Adverse Outcomes ◽  
Genome Wide Association Studies ◽  
Long Term Effects ◽  
Phenotypic Data ◽  
Increased Risk ◽  
Blood Clots ◽  
Genetically Determined

Epidemiological studies suggest that individuals with comorbid conditions including diabetes, chronic lung, inflammatory and vascular disease, are at higher risk of adverse COVID-19 outcomes. Genome-wide association studies have identified several loci associated with increased susceptibility and severity for COVID-19. However, it is not clear whether these associations are genetically determined or not. We used a Phenome-Wide Association (PheWAS) approach to investigate the role of genetically determined COVID-19 susceptibility on disease related outcomes. PheWAS analyses were performed in order to identify traits and diseases related to COVID-19 susceptibility and severity, evaluated through a predictive COVID-19 risk score. We utilised phenotypic data in up to 400,000 individuals from the UK Biobank, including Hospital Episode Statistics and General Practice data. We identified a spectrum of associations between both genetically determined COVID-19 susceptibility and severity with a number of traits. COVID-19 risk was associated with increased risk for phlebitis and thrombophlebitis (OR = 1.11, p = 5.36e-08). We also identified significant signals between COVID-19 susceptibility with blood clots in the leg (OR = 1.1, p = 1.66e-16) and with increased risk for blood clots in the lung (OR = 1.12, p = 1.45 e-10). Our study identifies significant association of genetically determined COVID-19 with increased blood clot events in leg and lungs. The reported associations between both COVID-19 susceptibility and severity and other diseases adds to the identification and stratification of individuals at increased risk, adverse outcomes and long-term effects.

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