<small id='u5hgp'></small><noframes id='u5hgp'>

  • <tfoot id='u5hgp'></tfoot>

      <legend id='u5hgp'><style id='u5hgp'><dir id='u5hgp'><q id='u5hgp'></q></dir></style></legend>
      <i id='u5hgp'><tr id='u5hgp'><dt id='u5hgp'><q id='u5hgp'><span id='u5hgp'><b id='u5hgp'><form id='u5hgp'><ins id='u5hgp'></ins><ul id='u5hgp'></ul><sub id='u5hgp'></sub></form><legend id='u5hgp'></legend><bdo id='u5hgp'><pre id='u5hgp'><center id='u5hgp'></center></pre></bdo></b><th id='u5hgp'></th></span></q></dt></tr></i><div id='u5hgp'><tfoot id='u5hgp'></tfoot><dl id='u5hgp'><fieldset id='u5hgp'></fieldset></dl></div>

          <bdo id='u5hgp'></bdo><ul id='u5hgp'></ul>

        1. Skip to main page content
          Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
          . 2021 Apr 16.
          doi: 10.1056/NEJMoa2105385. Online ahead of print.

          Pathologic Antibodies to Platelet Factor 4 after ChAdOx1 nCoV-19 Vaccination

          Affiliations

          Pathologic Antibodies to Platelet Factor 4 after ChAdOx1 nCoV-19 Vaccination

          Marie Scully et al. N Engl J Med. .

          Abstract

          Background: The mainstay of control of the coronavirus disease 2019 (Covid-19) pandemic is vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Within a year, several vaccines have been developed and millions of doses delivered. Reporting of adverse events is a critical postmarketing activity.

          Methods: We report findings in 23 patients who presented with thrombosis and thrombocytopenia 6 to 24 days after receiving the first dose of the ChAdOx1 nCoV-19 vaccine (AstraZeneca). On the basis of their clinical and laboratory features, we identify a novel underlying mechanism and address the therapeutic implications.

          Results: In the absence of previous prothrombotic medical conditions, 22 patients presented with acute thrombocytopenia and thrombosis, primarily cerebral venous thrombosis, and 1 patient presented with isolated thrombocytopenia and a hemorrhagic phenotype. All the patients had low or normal fibrinogen levels and elevated d-dimer levels at presentation. No evidence of thrombophilia or causative precipitants was identified. Testing for antibodies to platelet factor 4 (PF4) was positive in 21 patients, negative in 1 patient, and equivocal in 1 patient. On the basis of the pathophysiological features observed in these patients, we recommend that treatment with platelet transfusions be avoided because of the risk of progression in thrombotic symptoms and that the administration of a nonheparin anticoagulant agent and intravenous immune globulin be considered for the first occurrence of these symptoms.

          Conclusions: Vaccination against SARS-CoV-2 remains critical for control of the Covid-19 pandemic. A pathogenic PF4-dependent syndrome, unrelated to the use of heparin therapy, can occur after the administration of the ChAdOx1 nCoV-19 vaccine. Rapid identification of this rare syndrome is important because of the therapeutic implications.

          Similar articles

          • Thrombotic Thrombocytopenia after ChAdOx1 nCov-19 Vaccination.
            Greinacher A, Thiele T, Warkentin TE, Weisser K, Kyrle PA, Eichinger S. Greinacher A, et al. N Engl J Med. 2021 Apr 9. doi: 10.1056/NEJMoa2104840. Online ahead of print. N Engl J Med. 2021. PMID: 33835769
          • Safety and immunogenicity of the ChAdOx1 nCoV-19 vaccine against SARS-CoV-2: a preliminary report of a phase 1/2, single-blind, randomised controlled trial.
            Folegatti PM, Ewer KJ, Aley PK, Angus B, Becker S, Belij-Rammerstorfer S, Bellamy D, Bibi S, Bittaye M, Clutterbuck EA, Dold C, Faust SN, Finn A, Flaxman AL, Hallis B, Heath P, Jenkin D, Lazarus R, Makinson R, Minassian AM, Pollock KM, Ramasamy M, Robinson H, Snape M, Tarrant R, Voysey M, Green C, Douglas AD, Hill AVS, Lambe T, Gilbert SC, Pollard AJ; Oxford COVID Vaccine Trial Group. Folegatti PM, et al. Lancet. 2020 Aug 15;396(10249):467-478. doi: 10.1016/S0140-6736(20)31604-4. Epub 2020 Jul 20. Lancet. 2020. PMID: 32702298 Free PMC article. Clinical Trial.
          • Safety and immunogenicity of ChAdOx1 nCoV-19 vaccine administered in a prime-boost regimen in young and old adults (COV002): a single-blind, randomised, controlled, phase 2/3 trial.
            Ramasamy MN, Minassian AM, Ewer KJ, Flaxman AL, Folegatti PM, Owens DR, Voysey M, Aley PK, Angus B, Babbage G, Belij-Rammerstorfer S, Berry L, Bibi S, Bittaye M, Cathie K, Chappell H, Charlton S, Cicconi P, Clutterbuck EA, Colin-Jones R, Dold C, Emary KRW, Fedosyuk S, Fuskova M, Gbesemete D, Green C, Hallis B, Hou MM, Jenkin D, Joe CCD, Kelly EJ, Kerridge S, Lawrie AM, Lelliott A, Lwin MN, Makinson R, Marchevsky NG, Mujadidi Y, Munro APS, Pacurar M, Plested E, Rand J, Rawlinson T, Rhead S, Robinson H, Ritchie AJ, Ross-Russell AL, Saich S, Singh N, Smith CC, Snape MD, Song R, Tarrant R, Themistocleous Y, Thomas KM, Villafana TL, Warren SC, Watson MEE, Douglas AD, Hill AVS, Lambe T, Gilbert SC, Faust SN, Pollard AJ; Oxford COVID Vaccine Trial Group. Ramasamy MN, et al. Lancet. 2021 Dec 19;396(10267):1979-1993. doi: 10.1016/S0140-6736(20)32466-1. Epub 2020 Nov 19. Lancet. 2021. PMID: 33220855 Free PMC article. Clinical Trial.
          • Pathogenesis-directed therapy of 2019 novel coronavirus disease.
            Stratton CW, Tang YW, Lu H. Stratton CW, et al. J Med Virol. 2021 Mar;93(3):1320-1342. doi: 10.1002/jmv.26610. Epub 2020 Nov 10. J Med Virol. 2021. PMID: 33073355 Review.
          • Heparin-induced thrombocytopenia.
            Fabris F, Luzzatto G, Stefani PM, Girolami B, Cella G, Girolami A. Fabris F, et al. Haematologica. 2000 Jan;85(1):72-81. Haematologica. 2000. PMID: 10629596 Review.

          LinkOut - more resources