Leucocyte-endothelial interactions in chronic critical limb ischaemia.
Forearm blood samples were drawn from 18 patients with critical limb ischaemia (stage IIIb peripheral arterial obliterative disease) and 18 age- and sex-matched controls at 8.00 a.m., 2.00 p.m. and 8.00 p.m. We monitored the total and differential leucocyte counts and leucocyte expression of CD11/CD18 integrins (on whole blood samples by indirect immunofluorescence on a FACScan flow cytometer). Our results show no significant difference in any parameter at any stage of the day. At all study times, the total and differential leucocyte counts and granulocyte expression of CD11/CD18 were significantly (p < 0.001) greater in patients compared with controls. Associated with a high leucocyte count, constant up-regulation appears to be a feature of chronic tissue ischaemia. Activated neutrophils seem to aggravate peripheral arterial obliterative disease locally and may contribute to disseminated organ damage.