Thromb Haemost 2008; 99(04): 711-719
DOI: 10.1160/TH07-05-0334
Platelets and Blood Cells
Schattauer GmbH

Increased levels of circulating microparticles in patients with severe aortic valve stenosis

Philipp Diehl*
1   Department for Cardiology and Angiology
,
Ferenc Nagy*
1   Department for Cardiology and Angiology
,
Verena Sossong
1   Department for Cardiology and Angiology
,
Thomas Helbing
1   Department for Cardiology and Angiology
,
Friedhelm Beyersdorf
2   Department for Cardiovascular Surgery
,
Manfred Olschewski
3   Department for Biometry and Statistics, University Hospital Freiburg, Freiburg, Germany
,
Christoph Bode
1   Department for Cardiology and Angiology
,
Martin Moser
1   Department for Cardiology and Angiology
› Author Affiliations

Financial support: Work in M.M.‘s lab is supported by intramural funds and the Deutsche Forschungsgemeinschaft SFB-TR 23.
Further Information

Publication History

Received: 07 May 2007

Accepted after major revision: 06 February 2008

Publication Date:
25 November 2017 (online)

Preview

Summary

The mechanisms of the progression of aortic valve stenosis are unknown. The involvement of mononuclear cells and of chronic systemic inflammation has been suggested by analysis of pathological specimens. We hypothesize that shear stress caused by the constricted aortic orifice contributes to systemic proinflammation by activation of circulating blood cells and thereby generation of microparticles. Using flow cytometry we analyzed 22 patients with severe aortic valve stenosis (AVS) and 18 patient controls for the generation of circulating microparticles from platelet-(PMPs: CD31+/CD61+ or CD62P+), leukocyte-(LMPs: CD11b+) and endothelial cell (EMPs: CD62E+) origin. Apart from the constricted valve orifice groups were similar. PMPs were increased in AVS patients and their number correlated with valvular shear stress. Monocytes were activated in AVS patients, an observation that was also reflected by increased numbers of LMPs and by the detection of PMP-monocyte conjugates. Furthermore, EMPs reflecting the activation of endothelial cells but also conferring systemic inflammatory activity were increased in AVS patients and correlated with the number of activated monocytes. In conclusion, we show that AVS is accompanied by increased levels of microparticles and that shear stress can induce the formation of microparticles. Based on our results and histologic findings of other investigators the speculation that shear stress related to aortic valve stenosis induces a vicious circle including the generation of PMPs, the subsequent activation of monocytes and LMPs and finally the activation of endothelial cells contributing to the progress of aortic valve stenosis appears to be justified.

* These authors contributed equally.