The adhesion of leucocytes to vascular endothelium is fundamental to the pathogenesis of atherosclerosis and the acute coronary syndromes. The CD11b/CD18 receptor is particularly important in this process. This molecule is expressed on both neutrophils and monocytes. In common with other integrin receptors it consists of α and β subunits (CD11b and CD18, respectively), which allow binding of leucocytes to the endothelial surface.1

The aims of our study were: (1) to compare the expression of CD11b and CD18 on peripheral neutrophils and monocytes in patients with an acute coronary syndrome, patients with stable coronary artery disease, and healthy controls; and (2) to assess any functional change in neutrophil adhesion in the acute coronary syndrome.

Twenty two consecutive patients with an acute coronary syndrome were studied. None had received thrombolytics or glycoprotein IIb/IIIa inhibitors and none had undergone coronary revascularisation. All were on maintenance aspirin (n = 19) or had received > 12 hours of such treatment in hospital (n = 3). Twelve patients with stable coronary artery disease were also studied. All had a > 50% stenosis of at least one major coronary artery, had stable cardiac symptoms over the past six months, and were taking maintenance aspirin. The third group consisted of 12 healthy volunteers with no cardiac history or symptoms. These subjects were asked to take aspirin for three days before blood sampling. None of the patients or volunteers studied had …