In vitro effect of anti-β2 glycoprotein I antibodies on P-selectin expression, a marker of platelet activation

Submitted: 21 November 2011
Accepted: 30 November 2011
Published: 19 March 2012
Abstract Views: 1270
PDF: 571
Publisher's note
All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.

Authors

Antiphospholipid antibodies (aPL) associated with thromboembolic events and/or pregnancy morbidity characterize the so-called antiphospholipid syndrome (APS). Beta2glycoprotein I (β2GPI) is the main target antigen for aPL, but the pathogenic role of anti-β2GPI antibodies (aβ2GPI) is still unclear. Some authors assume they play a role in activating platelets. We evaluated the effects of aβ2GPI antibodies on platelet P-selectin expression. Aβ2GPI antibodies in the plasma of a pregnant APS patient were isolated by affinity chromatography at two different stages (catastrophic and quiescent) of the disease. Gel filtered platelets (100 x 109/L) from healthy volunteers were incubated with β2-GPI (20 µg/mL) and with different concentrations (5. 25 and 50 µg/mL) of aβ2GPI antibodies. P-selectin surface expression on platelets was assessed by flow cytometry using a specific fluorescent antibody directed against P-selectin. Aβ2GPI antibodies induced platelet activation only in the presence of thrombin receptor activator for peptide 6 (TRAP-6), a platelet agonist, at a subthreshold concentration. Aβ2GPI antibody enhancement on platelet surface P-selectin expression was stronger in the catastrophic than in the quiescent phase of the disease (47 vs 15%). TRAP-6 dependent platelet activation by aβ2GPI antibodies is consistent with the “two hit” pathogenetic hypothesis for thrombosis. Aβ2GPI antibodies induce higher platelet P-selectin expression during the active rather than the acute phases.

Dimensions

Altmetric

PlumX Metrics

Downloads

Download data is not yet available.

Citations

A. Bontadi, Cattedra e UOC di Reumatologia
Dipartimento di Medicina Clinica e Sperimentale

How to Cite

Bontadi, A., Ruffatti, A., Giannini, S., Falcinelli, E., Tonello, M., Hoxha, A., Gresele, P., & Punzi, L. (2012). In vitro effect of anti-β2 glycoprotein I antibodies on P-selectin expression, a marker of platelet activation. Reumatismo, 64(1), 35–39. https://doi.org/10.4081/reumatismo.2012.35