Journal of thrombosis and haemostasis : JTH
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J. Thromb. Haemost. · Nov 2021
LetterTo clot or not to clot? Ad is the question-Insights on mechanisms related to vaccine-induced thrombotic thrombocytopenia.
Vaccine-induced immune thrombotic thrombocytopenia (VITT) has caused global concern. VITT is characterized by thrombosis and thrombocytopenia following COVID-19 vaccinations with the AstraZeneca ChAdOx1 nCov-19 and the Janssen Ad26. COV2. ⋯ Here, we propose and discuss potential mechanisms in relation to adenovirus induction of VITT. We provide insights and clues into areas warranting investigation into the mechanistic basis of VITT, highlighting the unanswered questions. Further research is required to help solidify a pathogenic model for this condition.
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J. Thromb. Haemost. · Oct 2021
LetterVaccine-induced immune thrombotic thrombocytopenia (VITT) - update on diagnosis and management considering different resources.
Vaccine-induced immune thrombotic thrombocytopenia (VITT) is a rare but severe immunological reaction to the non-replicable adenoviral vector-based COVID-19 vaccines. Extreme activation of platelets and the coagulation system leads to a high risk of death from venous or arterial thrombosis or secondary hemorrhage. Public and clinician awareness has reduced mortality of VITT by nearly 90%. ⋯ This update has been summarized by the authors in an informal process with recommendations for low resource environments. We provide new available evidence on VITT to empower clinicians to recognize VITT early, then effectively diagnose and treat the disorder to reduce morbidity and mortality. We strongly encourage production of clear management pathways for primary care settings and hospital settings.
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J. Thromb. Haemost. · Oct 2021
Examining international practises in the management of pregnant women with von willebrand disease.
The management of pregnant women with von Willebrand disease (VWD) is complex as physiological pregnancy-induced increases in plasma von Willebrand factor (VWF) may be blunted or absent. Women with VWD experience a heightened risk of postpartum hemorrhage (PPH) and special consideration must be given regarding neuraxial anesthesia (NA) and the need for prophylaxis at time of delivery. These challenges are compounded by a lack of robust evidence to guide clinical decision-making. ⋯ This survey highlighted areas of uncertainty surrounding common management issues for pregnant women with VWD. These data underscore the need for international collaborative research efforts focused on peripartum management to improve care for pregnant women with VWD.
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J. Thromb. Haemost. · Oct 2021
Observational StudyComparison of adverse drug reactions among four COVID-19 vaccines in Europe using the EudraVigilance database: Thrombosis at unusual sites.
Real-world experience with adenoviral vector vaccines against COVID-19 raised some safety concerns. Cases of cerebral vein thrombosis (CVT) associated with thrombocytopenia have been observed after the first dose of the adenoviral vector vaccines CHADOX1 NCOV-19 and AD26.COV2.S. ⋯ This report on EudraVigilance data strengthens anecdotal findings on CVT following COVID-19 vaccinations. Although the European Medicines Agency released an alert only for CHADOX1 NCOV-19 and AD26.COV2.S, Tozinameran and CX-024414 also are complicated by CVT, albeit to lesser extent.
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J. Thromb. Haemost. · Sep 2021
Imbalance of von Willebrand factor and ADAMTS13 axis is rather a biomarker of strong inflammation and endothelial damage than a cause of thrombotic process in critically ill COVID-19 patients.
Critically ill patients with coronavirus disease 2019 (COVID-19) are prone to developing macrothrombosis and microthrombosis. COVID-19 has been reported to be rarely associated with thrombotic microangiopathies. A disintegrin and metalloprotease with thrombospondin type I repeats, member 13 (ADAMTS13) severe deficiency, the hallmark of thrombotic thrombocytopenic purpura (TTP), induces the formation of platelet, unusually large von Willebrand factor (VWF) multimer microthrombi. In immune-mediated TTP, ADAMTS13 adopts specifically an open conformation. The VWF/ADAMTS13 couple may contribute to the microthrombi formation in pulmonary alveolar capillaries in COVID-19. ⋯ We suggest that slightly decreased or normal ADAMTS13 activity and highly elevated VWF are rather biomarkers reflecting both the strong inflammation and the endothelial damage rather than drivers of the thrombotic process of COVID-19.