Up-regulation of circulating adhesion molecules in bronchiectasis.
Adhesion molecules are expressed on the surface of endothelial cells and leukocytes and are responsible for mediating the migration of intravascular leukocytes into inflamed tissue. Intensive recruitment of neutrophils into the airways occurs in bronchiectasis, although little is known about the role of adhesion molecules in this process. The authors, therefore, determined serum levels of E-selectin, intercellular adhesion molecule (ICAM)-1 and vascular adhesion molecule (VCAM)-1 in stable bronchiectasis patients (n=37) and healthy control subjects (n=17), and evaluated their relationship with clinical markers of disease severity in bronchiectasis. Serum levels of E-selectin, ICAM-1 and VCAM-1 in bronchiectasis patients were significantly higher than those in control subjects (p=0.02, <0.0001 and 0.0002 respectively). Both E-selectin and ICAM-1 levels were inversely related to forced expiratory volume in one second (FEV1)% predicted (r=-0.57, p<0.001; and r=-0.53, p=0.001 respectively), and FVC% predicted (r=-0.52, p=0.002; and r=-0.46, p=0.005). This was not the case for VCAM-1 levels. There was a correlation between serum ICAM-1 levels and 24 h sputum volume (r=0.34, p= 0.04). Serum E-selectin and ICAM-1, but not VCAM-1, levels showed correlation with the number of lung lobes affected by bronchiectasis (r=0.35, p=0.04 and r=0.34, p=0.04 respectively). These original observations strongly suggest that E-selectin, intercellular adhesion molecule-1 and Vascular adhesion molecule-1 could play a significant role in the pathogenesis of bronchiectasis.