Human leucocyte-endothelial interactions in peripheral arterial occlusive disease

This ex vivo study determined the expression of leucocyte adhesion receptors for endothelial adhesion molecules in 10 patients with peripheral arterial occlusive disease (PAOD) and in 10 healthy controls before and after treadmill exercise. Granulocytes from venous blood samples were separated on a Ficoll-Hypaque gradient and the phenotypical expression of CD11a/CD18 (LFA-1), CD11b/CD18 (Mac-1) and CD11c/CD18 (p150,95) was observed by double indirect immunofluorescence using specific monoclonal antibodies. The total and differential white blood cell counts were monitored before and after exercise. In the PAOD patients a significant reduction in the number of granulocytes expressing CD11b/CD18 (Mac-1) and CD11c/CD18 (p150,95) associated with a significant neutropenia was observed after exercise, suggesting that leucocyte-endothelial interactions occur during ischaemia.