[Erythrocyte adhesion to vascular endothelium: clinical applications]. / Adhésion des hématies à l'endothélium vasculaire: applications en pathologie.

INTRODUCTION: The objectives of this paper are to review the environmental factors, the different erythrocyte ligands and the corresponding endothelial receptors involved in adhesion. CURRENT KNOWLEDGE AND KEY POINTS: Leukocyte adhesion to vascular endothelium is related to inflammation and has been widely studied. The adhesion of erythrocytes to vascular endothelium has been investigated more recently, mainly in the physiopathology of three diseases: diabetes mellitus, sickle cell disease and malaria. The three diseases are characterized by microvascular complications and are deleterious for the red blood cell membrane. They lead to abnormal erythrocyte adhesion to vascular endothelium. Thus better understanding of the mechanisms involved in red blood cell adhesion to the endothelium is important since it might lead to the development of new therapeutic targets. Progress in this field might contribute to therapeutic improvement in sickle cell disease and to the development of an antimalarial vaccine. FUTURE PROSPECTS AND PROJECTS: However, additional studies focusing on in vivo endothelium heterogeneity, the different subpopulations of red blood cells and the diversity of Plasmodium falciparum strains are required. The consequences of such erythrocytes/endothelium interactions on the endothelial functions remain to be established.

In vitro assessment of endothelial cell adhesion mechanism on vascular patches.

Endothelial cell (EC) seeding of small caliber vascular grafts prior to their implantation has proved to significantly improve long-term patency in humans. We have previously demonstrated that a monolayer of EC could be obtained on type I collagen-coated knitted ultrathin polyster grafts (InterVascular, La Ciotat, France). Thus, the aim of the present work was to understand the nature of cell adhesion mechanisms involved in the cell /biomaterial interface, using HemaCarotid (InterVascular) patches made of type I collagen-coated knitted ultrathin polyster (type I collagen is used to coat patches to attain low permeability). By means of quantitative attachment tests, adhesion blocking assays, RT-PCR for the expression of beta1 integrin mRNA, indirect immunofluorescence with antivinculin antibody, we were able to show that EC are able to adhere to such surfaces by the means (non-unique) of cell surface receptors of the beta1 integrin group. However, the latter are probably downregulated at the cell/biomaterial interface.