Thromb Haemost 2013; 109(05): 901-908
DOI: 10.1160/TH12-03-0212
Blood Coagulation, Fibrinolysis and Cellular Haemostasis
Schattauer GmbH

Platelet and endothelial activation in catastrophic and quiescent antiphospholipid syndrome

Agnese Bontadi
1   Rheumatology Unit, Department of Medicine, University of Padua, Padua, Italy
,
Amelia Ruffatti
1   Rheumatology Unit, Department of Medicine, University of Padua, Padua, Italy
,
Emanuela Falcinelli
2   Division of Internal and Cardiovascular Medicine, Department of Internal Medicine, University of Perugia, Perugia, Italy
,
Silvia Giannini
2   Division of Internal and Cardiovascular Medicine, Department of Internal Medicine, University of Perugia, Perugia, Italy
,
Alessandro Marturano
2   Division of Internal and Cardiovascular Medicine, Department of Internal Medicine, University of Perugia, Perugia, Italy
,
Marta Tonello
1   Rheumatology Unit, Department of Medicine, University of Padua, Padua, Italy
,
Ariela Hoxha
1   Rheumatology Unit, Department of Medicine, University of Padua, Padua, Italy
,
Vittorio Pengo
3   Clinical Cardiology, Thrombosis Centre, University of Padua, Padua, Italy
,
Leonardo Punzi
1   Rheumatology Unit, Department of Medicine, University of Padua, Padua, Italy
,
Stefania Momi
2   Division of Internal and Cardiovascular Medicine, Department of Internal Medicine, University of Perugia, Perugia, Italy
,
Paolo Gresele
2   Division of Internal and Cardiovascular Medicine, Department of Internal Medicine, University of Perugia, Perugia, Italy
› Author Affiliations
Further Information

Publication History

Received: 02 April 2012

Accepted after major revision: 17 February 2013

Publication Date:
22 November 2017 (online)

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Summary

Antiphospholipid antibodies (aPL) seem to induce a prothrombotic state by activating endothelium and platelets, but no studies have evaluated systematically the effects of aPL from patients with the antiphospholipid syndrome (APS) in quiescent versus catastrophic phase. Our aims were to evaluate the in vitro effects on platelet activation of anti-β2 glycoprotein I (anti-β2GPI) antibodies isolated from APS patient in either quiescent or catastrophic phase and to investigate ex vivo platelet and endothelial activation in patients with quiescent or catastrophic APS. Anti-β2GPI antibodies were isolated from plasma of a pregnant woman in two different stages of APS (quiescent and catastrophic, respectively). They were co-incubated with washed platelets from healthy controls that were then challenged with TRAP-6 (thrombin receptor activating peptide 6) and the expression of P-selectin (P-sel) on platelets was assessed by flow cytometry. Moreover, plasma samples from six patients with quiescent, four with catastrophic APS and 10 controls were assessed for several markers of platelet and endothelial activation. The results showed that purified anti-β2GPI antibodies co-incubated with platelets enhanced TRAP-6-induced platelet P-sel expression. Notably, anti-β2GPI antibodies isolated during the catastrophic phase enhanced platelet P-sel expression more than antibodies isolated from the same patient in the quiescent stage of disease. Moreover, APS patients had significantly higher plasma levels of soluble (s) Psel, sCD40 ligand, soluble vascular cell adhesion molecule 1 and monocyte chemoattractant protein 1 than control subjects. In addition, sP-sel and von Willebrand factor activity were significantly higher during catastrophic than in quiescent phase.