Frontiers in Immunology (Oct 2020)

Anti-Phospholipid Antibodies in COVID-19 Are Different From Those Detectable in the Anti-Phospholipid Syndrome

  • Maria Orietta Borghi,
  • Maria Orietta Borghi,
  • Asmaa Beltagy,
  • Asmaa Beltagy,
  • Emirena Garrafa,
  • Emirena Garrafa,
  • Daniele Curreli,
  • Germana Cecchini,
  • Caterina Bodio,
  • Claudia Grossi,
  • Simonetta Blengino,
  • Angela Tincani,
  • Franco Franceschini,
  • Laura Andreoli,
  • Maria Grazia Lazzaroni,
  • Silvia Piantoni,
  • Stefania Masneri,
  • Francesca Crisafulli,
  • Duilio Brugnoni,
  • Maria Lorenza Muiesan,
  • Massimo Salvetti,
  • Gianfranco Parati,
  • Erminio Torresani,
  • Michael Mahler,
  • Francesca Heilbron,
  • Francesca Pregnolato,
  • Martino Pengo,
  • Francesco Tedesco,
  • Nicola Pozzi,
  • Pier Luigi Meroni

DOI
https://doi.org/10.3389/fimmu.2020.584241
Journal volume & issue
Vol. 11

Abstract

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BackgroundCritically ill patients with coronavirus disease 2019 (COVID-19) have a profound hypercoagulable state and often develop coagulopathy which leads to organ failure and death. Because of a prolonged activated partial-thromboplastin time (aPTT), a relationship with anti-phospholipid antibodies (aPLs) has been proposed, but results are controversial. Functional assays for aPL (i.e., lupus anticoagulant) can be influenced by concomitant anticoagulation and/or high levels of C reactive protein. The presence of anti-cardiolipin (aCL), anti-beta2-glycoprotein I (anti-β2GPI), and anti-phosphatidylserine/prothrombin (aPS/PT) antibodies was not investigated systematically. Epitope specificity of anti-β2GPI antibodies was not reported.ObjectiveTo evaluate the prevalence and the clinical association of aPL in a large cohort of COVID-19 patients, and to characterize the epitope specificity of anti-β2GPI antibodies.MethodsELISA and chemiluminescence assays were used to test 122 sera of patients suffering from severe COVID-19. Of them, 16 displayed major thrombotic events.ResultsAnti-β2GPI IgG/IgA/IgM was the most frequent in 15.6/6.6/9.0% of patients, while aCL IgG/IgM was detected in 5.7/6.6% by ELISA. Comparable values were found by chemiluminescence. aPS/PT IgG/IgM were detectable in 2.5 and 9.8% by ELISA. No association between thrombosis and aPL was found. Reactivity against domain 1 and 4-5 of β2GPI was limited to 3/58 (5.2%) tested sera for each domain and did not correlate with aCL/anti-β2GPI nor with thrombosis.ConclusionsaPL show a low prevalence in COVID-19 patients and are not associated with major thrombotic events. aPL in COVID-19 patients are mainly directed against β2GPI but display an epitope specificity different from antibodies in antiphospholipid syndrome.

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