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  3. PAD4-Induced NETosis Via Cathepsin G-Mediated Platelet-Neutrophil Interaction in ChAdOx1 Vaccine-Induced Thrombosis-Brief Report

PAD4-Induced NETosis Via Cathepsin G-Mediated Platelet-Neutrophil Interaction in ChAdOx1 Vaccine-Induced Thrombosis-Brief Report

  • Arterioscler Thromb Vasc Biol. 2023 Oct;43(10):e396-e403. doi: 10.1161/ATVBAHA.123.319522.
Roberto Carnevale # 1 2,  Martina Leopizzi # 1,  Marcello Dominici 3,  Giulia d'Amati 4,  Simona Bartimoccia 5,  Cristina Nocella 5,  Vittoria Cammisotto 5,  Alessandra D'Amico 1,  Valentina Castellani 6,  Francesco Baratta 5,  Alessia Bertelli 7,  Alessio Arrivi 3,  Danilo Toni 8,  Manuela De Michele 9,  Pasquale Pignatelli 5 10,  Rossella Marcucci 7,  Francesco Violi 5 10
Affiliations

Affiliations

  • 1 Department of Medical-Surgical Sciences and Biotechnologies, Sapienza University of Rome, Corso della Repubblica, Latina, Italy (R.C., M.L., A.D.A.).
  • 2 IRCCS Neuromed, Località Camerelle, Pozzilli (IS), Italy (R.C.).
  • 3 Interventional Cardiology Unit, Santa Maria Hospital, Terni, Italy (M.D., A.A.).
  • 4 Department of Radiological, Oncological and Pathological Sciences, Sapienza University of Rome, Italy (G.d.A.).
  • 5 Department of Clinical Internal, Anaesthesiological and Cardiovascular Sciences, Sapienza University of Rome, Italy (S.B., C.N., V. Cammisotto, F.B., P.P., F.V.).
  • 6 Department of General Surgery and Surgical Specialty, Sapienza University of Rome, Italy (V. Castellani).
  • 7 Atherothrombotic Disease Unit, Department of Experimental and Clinical Medicine, University of Florence, Azienda Ospedaliera Universitaria Careggi, Italy (A.B., R.M.).
  • 8 Emergency Department, Stroke Unit, Sapienza University of Rome, Italy (D.T.).
  • 9 Department of Human Neurosciences, Sapienza University of Rome, Italy (M.D.M.).
  • 10 Mediterranea Cardiocentro-Napoli, Via Orazio, Naples, Italy (P.P., F.V.).
  • # Contributed equally.
PMID: 37586040 DOI: 10.1161/ATVBAHA.123.319522
Abstract

Background: Vaccine-induced immune thrombotic thrombocytopenia (VITT) is a rare syndrome characterized by platelet anti-PF4 (platelet-activating antiplatelet factor 4)-related thrombosis. Platelet-neutrophil interaction has been suggested to play a role, but the underlying mechanism has not been fully elucidated.

Methods: The study included 10 patients with VITT after ChAdOx1 (chimpanzee adenovirus Oxford 1) nCoV-19 (Oxford-AstraZeneca) vaccine administration, 10 patients with ischemic stroke (IS), 10 patients with acute deep vein thrombosis, and 10 control subjects in whom blood levels of neutrophil extracellular traps (NETs), soluble TF (tissue factor), and Thrombin generation were examined. Furthermore, we performed in vitro studies comparing the effect of serum from patients and controls on NETs formation. Finally, immunohistochemistry was performed in cerebral thrombi retrieved from a patients with VITT and 3 patients with IS.

Results: Compared with patients with IS, patients with deep vein thrombosis, controls, and patients with VITT had significantly higher blood values of CitH3 (citrullinated histone H3), soluble TF, D-dimer, and prothrombin fragment 1+2 (P<0.0001). Blood CitH3 significantly correlated with blood soluble TF (Spearman rank correlation coefficient=0.7295; P=0.0206) and prothrombin fragment 1+2 (Spearman rank correlation coefficient=0.6809; P<0.0350) in patients with VITT. Platelet-neutrophil mixture added with VITT plasma resulted in higher NETs formation, soluble TF and Thrombin generation, and platelet-dependent thrombus growth under laminar flow compared with IS and deep vein thrombosis plasma; these effects were blunted by PAD4 (Protein Arginine Deiminase 4) and Cathepsin G inhibitors, anti-FcγRIIa (Fc receptor for IgG class IIa), and high doses of heparin. Immunohistochemistry analysis showed a more marked expression of PAD4 along with more diffuse neutrophil infiltration and NETs formation as well as TF and Cathepsin expression in VITT thrombus compared with thrombi from patients with IS.

Conclusions: Patients with VITT display enhanced thrombogenesis by PAD4-mediated NETs formation via Cathepsin G-mediated platelet/neutrophil interaction.

Keywords

extracellular traps; ischemic stroke; neutrophil; thrombocytopenia; thrombosis.

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