4,406 results match your criteria Heparin-Induced Thrombocytopenia


Anti-PF4 testing for Vaccine-induced Immune Thrombocytopenia and Thrombosis (VITT). Results from a NEQAS, ECAT and SSC collaborative exercise in 385 centres worldwide.

J Thromb Haemost 2022 May 23. Epub 2022 May 23.

UK NEQAS (Blood Coagulation), Sheffield, UK.

Background: Vaccine-induced immune thrombocytopenia and thrombosis (VITT) following the administration of the AstraZeneca (AZ) ChAdOx1 nCOV-19 vaccine is a well-recognised clinical phenomenon. The associated clinical and laboratory features have included thrombosis at unusual sites, thrombocytopenia, raised D-Dimer levels and positivity for immunoglobulin G (IgG) anti-platelet factor 4 (PF4) antibodies.

Objectives: A collaborative external quality assessment (EQA) exercise was carried out by distributing 5 lyophilised samples from subjects with VITT and one from a healthy subject to 500 centres performing Heparin Induced Thrombocytopenia (HIT) testing. Read More

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Vaccine-induced prothrombotic immune thrombocytopenia without thrombosis may not require immune modulatory therapy: A case report.

Res Pract Thromb Haemost 2022 May 18;6(4):e12716. Epub 2022 May 18.

Division of Hematology University of British Columba Vancouver British Columbia Canada.

Background: Vaccine-induced immune thrombotic thrombocytopenia (VITT) is a rare complication of the ChAdOx1 nCoV-19 and Ad26.COV2.S COVID-19 vaccines. Read More

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A proven perioperative protocol for free flap surgery in a patient with heparin-induced thrombocytopenia.

J Plast Reconstr Aesthet Surg 2022 May 6. Epub 2022 May 6.

Department of Plastic and Reconstructive Surgery, Liverpool Hospital, Sydney, Australia.

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Thrombosis and coagulopathy in COVID-19 patients rceiving ECMO: A narrative review of current literature.

J Cardiothorac Vasc Anesth 2022 Mar 31. Epub 2022 Mar 31.

Columbia University College of Physicians and Surgeons, New York, NY, United States; Center for Acute Respiratory Failure, New York Presbyterian Hospital, New York, NY, United States.

Extracorporeal membrane oxygenation (ECMO) is an established part of the treatment algorithm for coronavirus disease 2019 (COVID-19)-related acute respiratory distress syndrome. An intense inflammatory response may cause an imbalance in the coagulation cascade making both thrombosis and bleeding common and notable features of the clinical management of these patients. Large observational and retrospective studies provide a better understanding of the pathophysiology and management of bleeding and thrombosis in COVID-19 patients requiring ECMO. Read More

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Cardiovascular and Hematologic Complications of COVID-19 Vaccines.

Cardiol Rev 2022 May 16. Epub 2022 May 16.

Departments of Medicine and Cardiology, New York Medical College/Westchester Medical Center, Valhalla, NY.

COVID-19 is a pro-thrombotic and cardiac-damaging disease. There are four vaccines against COVID-19 currently approved in North America, including the mRNA vaccines by Pfizer and Moderna, and the adenovirus vector vaccines by Johnson and Johnson and AstraZeneca. These vaccines have been proven effective in preventing morbidity and mortality in patients who were exposed to COVID-19 infection, but the vaccines have also been associated with complications. Read More

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Accelerated heparin-induced thrombocytopenia in a COVID-19 patient; a case report with literature review.

Ann Med Surg (Lond) 2022 Jun 11;78:103749. Epub 2022 May 11.

College of Medicine, University of Sulaimani, Madam Mitterrand Street, Sulaimani, Kurdistan, Iraq.

Introduction: Heparin-induced thrombocytopenia (HIT) is a rare and serious immune-mediated complication of heparin therapy which is seldom reported in association with COVID-19. This report aims to present a case of accelerated HIT in a severe COVID-19 patient.

Case Report: A 63-year-old man presents with symptoms of COVID-19 for one week. Read More

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A case of severe COVID-19 with pulmonary thromboembolism related to heparin-induced thrombocytopenia during prophylactic anticoagulation therapy.

J Infect Chemother 2022 May 11. Epub 2022 May 11.

Department of General Internal Medicine, Kyushu University Hospital, Fukuoka, Japan.

A 53-year-old male Japanese patient with COVID-19 was admitted to our hospital after his respiratory condition worsened on day 9 of the disease. With the diagnosis of severe COVID-19, treatment with remdesivir, dexamethasone, and unfractionated heparin was started for the prevention of thrombosis. Although the patient's respiratory status data improved after treatment, severe respiratory failure persisted. Read More

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Monoclonal and oligoclonal anti-Platelet Factor 4 antibodies mediate VITT.

Blood 2022 May 13. Epub 2022 May 13.

Mayo Clinic, Rochester, Minnesota, United States.

COVID-19 vaccines have been associated with a rare life-threatening thrombotic and thrombocytopenic adverse reaction, vaccine-induced immune thrombotic thrombocytopenia (VITT) characterized by high levels of platelet-activating anti-platelet factor 4 (PF4) antibodies. In this study, we evaluated the pathogenesis and clonality of VITT antibodies from five patients with VITT secondary to ChAdOx1 nCoV-19 (n=1) and Ad26.COV2. Read More

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Heparin-Induced Thrombocytopenia in Patients With Mechanical Circulatory Support.

J Cardiothorac Vasc Anesth 2022 Apr 8. Epub 2022 Apr 8.

Department of Anesthesiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK.

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Genome-wide association study of platelet factor 4/heparin antibodies in heparin-induced thrombocytopenia.

Blood Adv 2022 May 9. Epub 2022 May 9.

Department of Biomedical Informatics, Vanderbilt University Medical Center, Nashville, TN, United States.

Heparin, a widely used anticoagulant, carries the risk of an antibody mediated adverse drug reaction, heparin-induced thrombocytopenia (HIT). A subset of heparin-treated patients produces detectable levels of antibodies against complexes of heparin bound to circulating platelet factor 4 (PF4). Using a genome-wide association study (GWAS) approach, we aimed to identify genetic variants associated with anti-PF4/heparin antibodies that account for the variable antibody response seen in HIT. Read More

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Use of nafamostat mesilate for anticoagulation during extracorporeal membrane oxygenation: A systematic review.

Artif Organs 2022 May 9. Epub 2022 May 9.

Department of Anaesthesia and Intensive Care, A.O.U. "Policlinico-San Marco", Catania, Italy.

Background: Extracorporeal membrane oxygenation (ECMO) represents an advanced option for supporting refractory respiratory and/or cardiac failure. Systemic anticoagulation with unfractionated heparin (UFH) is routinely used. However, patients with bleeding risk and/or heparin-related side effects may necessitate alternative strategies: among these, nafamostat mesilate (NM) has been reported. Read More

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A Real-World Comparative Effectiveness Analysis of Thromboprophylactic Use of Enoxaparin Versus Unfractionated Heparin in Abdominal Surgery Patients in a Large U.S. Hospital Database.

Hosp Pharm 2022 Feb 19;57(1):121-129. Epub 2021 Jan 19.

Livongo Health, Mountain View, CA, USA.

Little is known about outcomes associated with enoxaparin versus unfractionated heparin (UFH) for venous thromboembolism (VTE) prophylaxis in abdominal surgery patients in U.S. clinical practice. Read More

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February 2022

Pathogenesis of vaccine-induced immune thrombotic thrombocytopenia (VITT).

Semin Hematol 2022 Apr 23;59(2):97-107. Epub 2022 Feb 23.

Institute for Anatomy and Cell Biology, University Medicine Greifswald, Greifswald, Germany.

Vaccine-induced immune thrombotic thrombocytopenia (VITT; synonym, thrombosis with thrombocytopenia syndrome, is associated with high-titer immunoglobulin G antibodies directed against platelet factor 4 (PF4). These antibodies activate platelets via platelet FcγIIa receptors, with platelet activation greatly enhanced by PF4. Here we summarize the current concepts in the pathogenesis of VITT. Read More

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Treatment of vaccine-induced immune thrombotic thrombocytopenia (VITT).

Semin Hematol 2022 Apr 7;59(2):89-96. Epub 2022 Mar 7.

Department of Medicine, Michael G. DeGroote School of Medicine, McMaster University, Hamilton, Ontario, Canada; McMaster Center for Transfusion Research, McMaster University, Hamilton, Ontario, Canada; Service of Benign Hematology, Department of Medicine, Hamilton Health Sciences, Hamilton, Ontario Canada; Department of Pathology and Molecular Medicine, Michael G. DeGroote School of Medicine, McMaster University, Hamilton, Ontario, Canada; Transfusion Medicine, Hamilton Regional Laboratory Medicine Program, Hamilton, Ontario, Canada. Electronic address:

Vaccine-induced immune thrombotic thrombocytopenia (VITT) is a novel prothrombotic disorder characterized by thrombosis, thrombocytopenia, and disseminated intravascular coagulation identified in hundreds of recipients of ChAdOx1 nCoV-19 (Oxford/AstraZeneca), an adenovirus vector coronavirus disease 2019 (COVID-19) vaccine. VITT resembles heparin-induced thrombocytopenia (HIT) in that patients have platelet-activating anti-platelet factor 4 antibodies; however, whereas heparin typically enhances platelet activation by HIT antibodies, VITT antibody-induced platelet activation is often inhibited in vitro by pharmacological concentrations of heparin. Further, the thrombotic complications in VITT feature much higher frequencies of atypical thrombosis, most notably cerebral vein thrombosis and splanchnic vein thrombosis, compared with HIT. Read More

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Laboratory testing for VITT antibodies.

Semin Hematol 2022 Apr 7;59(2):80-88. Epub 2022 Mar 7.

Institute for Transfusion Medicine, University Medicine Greifswald, Greifswald, Germany.

Vaccine-induced immune thrombotic thrombocytopenia (VITT) is a highly prothrombotic disorder that like heparin-induced thrombocytopenia (HIT) is caused by platelet-activating antibodies that recognize platelet factor 4 (PF4). However, unlike HIT-where heparin at low concentrations (0.1-0. Read More

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Platelet-activating anti-PF4 disorders: An overview.

Semin Hematol 2022 Apr 20;59(2):59-71. Epub 2022 Feb 20.

Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada; Department of Medicine, McMaster University, Hamilton, ON, Canada; Transfusion Medicine, Hamilton Regional Laboratory Medicine Program, Hamilton, ON, Canada; Service of Benign Hematology, Hamilton Health Sciences, Hamilton General Hospital, Hamilton, ON, Canada; McMaster Center for Transfusion Research, McMaster University, Hamilton, ON, Canada. Electronic address:

Platelet factor 4 (PF4) is a highly cationic tetrameric protein that can be targeted by platelet-activating anti-PF4 antibodies of immunoglobulin G (IgG) class. Certain features of PF4, including its multivalent nature (duplicate antigen sites per tetramer), the ability of many PF4 tetramers to undergo close approximation through charge neutralization, and the dimeric binding of IgG molecules, results in formation of IgG-containing immune complexes in situ on platelets, neutrophils, and monocytes, resulting in Fcγ receptor-mediated pancellular activation that also activates hemostasis (potential for disseminated intravascular coagulation). This review discusses 4 anti-PF4 disorders: classic heparin-induced thrombocytopenia ([HIT]; triggered by heparin and certain other polyanionic pharmaceuticals, featuring predominantly heparin-dependent antibodies), autoimmune HIT (aHIT; severe subtype of HIT that features both heparin-dependent and heparin-independent platelet-activating antibodies), and spontaneous HIT (non-heparin triggers such as knee replacement surgery and infection; predominantly heparin-independent platelet-activating antibodies). Read More

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Covid19 vaccination-associated portal vein thrombosis - an interdisciplinary clinical challenge.

Clin Res Hepatol Gastroenterol 2022 Apr 30:101932. Epub 2022 Apr 30.

Department of Surgery, University Hospital Regensburg, 93053 Regensburg, Germany. Electronic address:

Despite one of the largest vaccination campaigns in human history, the COVID-19 pandemic has not been yet defeated. More than 10 billion doses of COVID-19 vaccine have been administered worldwide. AstraZeneca's Vaxzevria (ChAdOx1 nCoV-19 / AZD1222) was approved as the first viral vector-based vaccine in the EU on 29 January 2021. Read More

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The Efficacy and Safety of Bivalirudin Versus Heparin in the Anticoagulation Therapy of Extracorporeal Membrane Oxygenation: A Systematic Review and Meta-Analysis.

Front Pharmacol 2022 14;13:771563. Epub 2022 Apr 14.

Department of Cardiology, West China Hospital of Sichuan University, Chengdu, China.

Bivalirudin is a direct thrombin inhibitor (DTI) that can be an alternative to unfractionated heparin (UFH). The efficacy and safety of bivalirudin in anticoagulation therapy in extracorporeal membrane oxygenation (ECMO) remain unknown. This study followed the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. Read More

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Vaccine-Induced Thrombotic Thrombocytopenia: A Case of Splanchnic Veins Thrombosis.

Cureus 2022 Mar 26;14(3):e23507. Epub 2022 Mar 26.

Internal Medicine, Ministry of Health, Riyadh, SAU.

Vaccines have been vital in preventing and curbing the spread of SARS-CoV-2 infection. Adenoviral vector-based vaccines, namely the ChAdOx1-S vaccine (AstraZeneca, Cambridge, UK) and Ad26.COV2. Read More

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Thrombocytopenia and splenic platelet directed immune responses after intravenous ChAdOx1 nCov-19 administration.

Blood 2022 Apr 29. Epub 2022 Apr 29.

Klinikum der Universität München, Muenchen, Germany.

Vaccines against SARS-CoV-2 are based on a range of novel platforms, with adenovirus-based approaches (like ChAdOx1 nCov-19) being one of them. Recently a novel complication of SARS-CoV-2 targeted adenovirus vaccines has emerged: immune thrombocytopenia (ITP), either isolated, or accompanied by thrombosis (then termed VITT). This complication is characterized by low platelet counts, and in the case of VITT also by platelet-activating platelet factor 4 (PF4) antibodies reminiscent of heparin-induced thrombocytopenia leading to a prothrombotic state with clot formation at unusual anatomic sites. Read More

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The Use of Prothrombin Complex Concentrates: Results of a Nationwide Survey of Critical Care Pharmacists.

J Pharm Pract 2022 Apr 14;35(2):197-204. Epub 2020 Oct 14.

Department of Clinical Pharmacy, 15503University of Colorado Skaggs School of Pharmacy and Pharmaceutical Sciences, Aurora, CO, USA.

Background: Prothrombin complex concentrates (PCCs) are frequently used.

Objective: To elucidate practices and perceptions of proprietary and nonproprietary PCCs use.

Methods: An electronic pretested cross-sectional survey e-mailed thrice to 1 critical care pharmacist at 1170 US institutions. Read More

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Assessment and Monitoring of Coagulation in Patients with COVID-19: A Review of Current Literature.

Hamostaseologie 2022 Apr 27. Epub 2022 Apr 27.

Center for Clinical Transfusion Medicine, University Hospital of Tuebingen, Tuebingen, Germany.

Coagulation abnormalities are common in patients with COVID-19 and associated with high morbidity and mortality. It became a daily challenge to navigate through these abnormal laboratory findings and deliver the best possible treatment to the patients. The unique character of COVID-19-induced coagulopathy necessitates not only a dynamic follow-up of the patients in terms of hemostatic findings but also the introduction of new diagnostic methods to determine the overall function of the coagulation system in real time. Read More

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Vaccine-Inducted Thrombotic Thrombocytopenia and Covid-19 Vaccines: Case Series.

Pril (Makedon Akad Nauk Umet Odd Med Nauki) 2022 Apr 22;43(1):49-55. Epub 2022 Apr 22.

Diagnostic Centre Gurev, Kavadarci, RN Macedonia.

Vaccine-induced thrombotic thrombocytopenia (VITT) is a condition similar to heparin-induced thrombocytopenia (HIT), but it is associated with prior administration of COVID-19 vaccines without prior exposure to heparin. The incidence of VITT is not certain, but it appears to be extremely rare. Reports of unusual and severe thrombotic events, including cerebral and splanchnic venous thrombosis and other autoimmune adverse reactions, such as immune thrombocytopenia or thrombotic microangiopathies in connection with some of the SARS-CoV-2 vaccines, have caused a great deal of concern within the population and the medical community. Read More

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Early Utilization of Intravenous Immunoglobulin in Heparin-Induced Thrombocytopenia for Limb Salvaging Purposes.

Cureus 2022 Mar 15;14(3):e23202. Epub 2022 Mar 15.

Research, Richmond University Medical Center, Staten Island, USA.

We present a case of a 28-year-old diabetic female who presented with high-burden lower extremity deep vein thrombosis (DVT) after previous exposure to unfractionated heparin (UFH). Heparin was discontinued, and non-heparin parenteral anticoagulant, argatroban, was started based on a high clinical suspicion of heparin-induced thrombocytopenia with thrombosis (HITT). The diagnosis of HIT was later proven by positive immune and functional assays. Read More

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Heparin-Induced Thrombocytopenia Caused by Preventive Anticoagulation After Femoral Intertrochanteric Fracture Surgery: a Case Report.

Clin Lab 2022 Apr;68(4)

Background: Heparin-induced thrombocytopenia (HIT) is a severe complication caused by heparin. It is characterized by occult onset and missed diagnosis. Misdiagnosis easily occurs. Read More

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Aortic root thrombus causing non-ST elevation myocardial infarction after left ventricular assist device.

Perfusion 2022 Apr 20:2676591221096228. Epub 2022 Apr 20.

Internal Medicine, 8405MedStar Washington Hospital Center, Washington, D.C., USA.

A 61-year-old male presented with a history of ischemic cardiomyopathy requiring left ventricular assist device (LVAD) implantation 9 months prior to presentation. The patient was on aspirin and warfarin as part of his LVAD management. The patient had chest pain and was found to have non-ST elevation myocardial infarction. Read More

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Heparin-Induced Thrombocytopenia in COVID-19: A Systematic Review.

Anesth Essays Res 2021 Oct-Dec;15(4):341-347. Epub 2022 Mar 8.

Department of Anaesthesiology and Critical Care, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India.

Background: It has been more than a year since the whole world is struggling with COVID-19 pandemic and may experience resurgences in the near future. Along with severe pneumonia, this disease is notorious for extensive thromboembolic manifestations. That is why experts advocated aggressive anticoagulation as a part of the therapy since the beginning. Read More

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Hospitalized patients are needlessly over-tested for heparin induced thrombocytopenia.

Eur J Intern Med 2022 Apr 11. Epub 2022 Apr 11.

Department of Medicine, Section of Hematology and Oncology, Louisiana State University Health Sciences Center, Shreveport, LA, United States; Feist Weiller Cancer Center, 1501, Kings Highway, Shreveport, LA 71103, United States. Electronic address:

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Delayed-Onset Heparin-Induced Thrombocytopenia With Cerebral Venous Sinus Thrombosis Following Total Knee Arthroplasty: Case Report.

Neurohospitalist 2022 Apr 26;12(2):328-331. Epub 2021 Aug 26.

Department of Neurology, Mayo Clinic, Rochester, MN, USA.

Heparin-induced thrombocytopenia (HIT) is a prothrombotic state caused by autoantibodies against platelet factor 4 (PF4)-heparin complexes. Although HIT typically presents 5-10 days after the initiation of heparin, thrombosis and thrombocytopenia may occur up to several weeks following heparin withdrawal, so-called delayed-onset HIT. Although rare, there have been isolated reports of HIT-induced cerebral venous sinus thrombosis (CVST), which carry high rates of morbidity and mortality. Read More

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Cerebral Venous Sinus Thrombosis due to Thrombosis with Thrombocytopenia Syndrome Following Ad26.COV2.S: A First Real-World Case Report of a Male Subject.

Neurohospitalist 2022 Apr 23;12(2):346-351. Epub 2021 Dec 23.

Department of Internal Medicine, Vanderbilt University Medical Center, Nashville, TN, USA.

Thrombosis with Thrombocytopenia Syndrome (TTS) or Vaccine-induced Immune Thrombotic Thrombocytopenia (VITT) had been reported in patients receiving the Ad26.COV2.S vaccination (Johnson & Johnson [J&J]/Janssen) vaccine. Read More

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