Institut d’hématologie et d’immunologie, INSERM U143, Faculté de Médecine, 4 rue Kirschleger, 67085 Strasbourg Cedex
Activated or apoptotic cells release in the pericellular space, small sub-micrometric membrane fragments termed “microparticles”. These entities, shed in the blood flow, bear procoagulant phospholipids and tissue factors and other membrane proteins, receptors and ligands, characteristic of the cells they originate from. Acting as vectors of biological information, microparticles are able to induce remote physiologic processes which are particularly relevant under pathological settings associated with thrombotic risk. Microparticles take part in all stages of the atherothrombotic process. Their presence in the blood flow could favour the first stages of plaque formation and modulate its stability. Microparticles from the plaque are mainly produced by apoptotic macrophages and smooth muscle cells. They participate in the thrombotic process following plaque rupture by providing high amounts of procoagulant phospholipids combined with tissue factor. The most recent studies point to circulating microparticles as an effector in thrombosis and inflammation coupling and suggest that microparticles could become a diagnosis tool, particularly in cardiovascular risk stratification. The correlation established between most relevant cardiovascular risk factors and microparticles could even make them a new therapeutic target.