Artigos
VACINAS CONTRA A COVID-19: FENÓMENOS TROMBÓTICOS COM TROMBOCITOPENIA
21 Maio 2021
Casos extremamente raros de trombose acompanhada de trombocitopenia foram relatados em recetores de duas das vacinas COVID-19 (ChAdOx1 nCoV-19/AZD1222 [AstraZeneca] ou Ad26.COV2.S [Janssen/Johnson & Johnson]). Uma explicação possível para o aparecimento destes eventos é uma resposta imunológica, que seria similar à trombocitopenia induzida por heparina.
Os fatores de risco desta possível reação adversa são desconhecidos e os locais pouco habituais de trombose (seios venosos cerebrais, veias esplâncnicas, artérias) permanecem inexplicados. As autoridades e outros especialistas indicam que os benefícios da vacinação superam este risco muito raro, que está a ser monitorizado ativamente.
Os indivíduos que recebem alguma das vacinas contra a COVID-19 associadas a esta reação adversa devem ser informados sobre os benefícios e riscos da vacinação, incluindo informações sobre este evento adverso extremamente raro, como vigiar os sintomas e as ações a tomar.
LEITURA RECOMENDADA
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https://www.infarmed.pt/web/infarmed/infarmed/-/journal_content/56/15786/4316779
VAXZEVRIA/COVID-19 Vaccine AstraZeneca: link between the vaccine and the occurrence of thrombosis in combination with thrombocytopenia. Direct Healthcare Professional Communication, 13/04/2021.
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COVID-19 Vaccine Janssen: EMA finds possible link to very rare cases of unusual blood clots with low blood platelets. 20/04/2021.
https://www.ema.europa.eu/en/news/covid-19-vaccine-janssen-ema-finds-possible-link-very-rare-cases-unusual-blood-clots-low-blood
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COVID-19 Vaccine Janssen: link between the vaccine and the occurrence of thrombosis in combination with thrombocytopenia. Direct Healthcare Professional Communication, 26/04/21.
https://www.ema.europa.eu/en/medicines/dhpc/covid-19-vaccine-janssen-link-between-vaccine-occurrence-thrombosis-combination-thrombocytopenia
https://www.ema.europa.eu/en/medicines/dhpc/covid-19-vaccine-janssen-link-between-vaccine-occurrence-thrombosis-combination-thrombocytopenia
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The Lancet Haematology. COVID-19 vaccines: building and maintaining confidence. Lancet Haematol. 2021 May; 8(5): e305. doi: 10.1016/S2352-3026(21)00107-1.
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Cines DB, Bussel JB. SARS-CoV-2 Vaccine-Induced Immune Thrombotic Thrombocytopenia. N Engl J Med. 2021 Apr 16: vNEJMe2106315. doi: 10.1056/NEJMe2106315. Epub ahead of print.
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Sholzberg M, Arnold DM, Laupacis A. Recognizing, managing and reporting vaccine-induced immune thrombotic thrombocytopenia. CMAJ. 2021 May 14:cmaj.210882. doi: 10.1503/cmaj.210882. Epub ahead of print.
https://www.cmaj.ca/content/cmaj/early/2021/05/13/cmaj.210882.full.pdf
https://www.cmaj.ca/content/cmaj/early/2021/05/13/cmaj.210882.full.pdf
Scully M, Singh D, Lown R, Poles A, Solomon T, Levi M, Goldblatt D, Kotoucek P, Thomas W, Lester W. Pathologic Antibodies to Platelet Factor 4 after ChAdOx1 nCoV-19 Vaccination. N Engl J Med. 2021 Apr 16. doi: 10.1056/NEJMoa2105385.
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Pottegård A, Lund LC, Karlstad Ø, Dahl J, Andersen M, Hallas J, et al. Arterial events, venous thromboembolism, thrombocytopenia, and bleeding after vaccination with Oxford-AstraZeneca ChAdOx1-S in Denmark and Norway: population based cohort study. BMJ. 2021 May 5; 373: n1114. doi: 10.1136/bmj.n1114.
https://www.bmj.com/content/bmj/373/bmj.n1114.full.pdf
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Greinacher A, Thiele T, Warkentin TE, Weisser K, Kyrle PA, Eichinger S. Thrombotic Thrombocytopenia after ChAdOx1 nCov-19 Vaccination. N Engl J Med. 2021 Apr 9: NEJMoa2104840. doi: 10.1056/NEJMoa2104840. Epub ahead of print.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8095372/pdf/NEJMoa2104840.pdf
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8095372/pdf/NEJMoa2104840.pdf