Induced sputum of patients with chronic obstructive pulmonary disease (COPD) contains adhesion-promoting, therapy-sensitive factors

Objective: The aim of this study was to investigate whether sputum of COPD patients before and after treatment with inhaled corticosteroids (IHC) or N -acetylcysteine (NAC) exerts any effect on the adhesion of isolated polymor phonuclear cells (PMNs) to cultured endothelial cells. Methods: A human endothelial cell line was grown to confluence before use i n adhesion experiments. PMNs were obtained from normal, non-smoking volunte ers and preincubated (30 min, 37 degrees C) with diluted sputum sol obtaine d from COPD patients before the cells were put on the endothelial cells. Results: Basal adhesion of unstimulated PMNs after 30 min at 37 degrees C i n 5% CO2 was 15.9 +/- 1.1% (mean +/- SEM, n = 9). A significant enhancement of the adhesion to 33.0 +/- 1.4% (n = 11, P <0.0001) was observed with spu tum obtained from COPD patients before treatment with IHC, and 34.6 +/- 1.5 % (n = 10, P <0.0001) before treatment with NAG. Administration of IHC for 8 weeks resulted in an adhesion of 27.7 +/- 2.4%, which is an inhibition of 31% (n = 11, P <0.05). However, treatment for 8 weeks with NAC showed no c hange in the adhesion of stimulated PMNs. Long-term treatment with NAC show ed a gradual decrease of adhesion (n = 9, P <0.05), whereas long-term treat ment with THC lead to an increase in adhesion (n = 10, P <0.02). Conclusions: These results indicate that factors locally produced in the ai rways of COPD patients may promote adhesion of neutrophils to endothelium. They further suggest that glucocorticoids may only have a short-term transi ent effect on adhesion, whereas NAC showed effects on the adhesion after ad ministration for longer periods.