EXPRESSION OF ADHESION MOLECULES AND G-PROTEINS IN CIRCULATING NEUTROPHILS IN CHRONIC OBSTRUCTIVE PULMONARY-DISEASE

We investigated the expression of adhesion molecules in circulating ne utrophils (lymphocyte function-associated antigen-1 [LFA-1], Mac-1, an d L-selectin) and endothelial cells (soluble intercellular adhesion mo lecule-1 [slCAM-1]) in 23 patients with stable chronic obstructive pul monary disease (COPD), 18 subjects with exacerbated COPD, and 23 healt hy volunteers. Also, in these circulating neutrophils, we assessed the expression of two G protein subunits (G alpha s and G alpha i1/2). Co mpared with control subjects, patients with stable COPD showed increas ed expression of Mac-1 (p < 0.001) and lower levels of slCAM-1 (p = 0. 002); LFA-1 and L-selectin expression was similar in patients and cont rol subjects. During exacerbations, compared with stable patients, the expression of Mac-1 and LFA-1 was reduced (p < 0.001). Finally, the e xpression of G alpha s (but not G alpha i1/2) was also reduced (p < 0. 001) in circulating neutrophils of patients with COPD, irrespective of the clinical condition of the patient. These results indicate that in patients with COPD: (1) the expression of some neutrophil adhesion mo lecules (Mac-1) is abnormal, and that this pattern changes during exac erbations; (2) there may be a form of endothelial dysfunction, as sugg ested by the low slCAM-1 levels; (3) the expression of G protein subun it (G alpha s) in circulating neutrophils is downregulated, irrespecti ve of their clinical conditions. Overall, these results indicate the p resence of significant systemic abnormalities in COPD.