Lactadherin mediates sickle cell adhesion to vascular endothelial cells in flowing blood.

Increased exposure of sickle red blood cells to phosphatidylserine promotes its adhesion to the endothelium. A monoclonal antibody to lactadherin, a phosphatidylserine binding protein, inhibits sickle cell adhesion to histamine-stimulated endothelial cells in flowing blood. Added lactadherin enhances the adhesion via the integrin alphaVbeta3. These results indicate that lactadherin can mediate phosphatidylserine-expressing sickle cell adhesion to the endothelium.