[The study of inflammatory mediators and pulmonary ventilatory capacity in patients with chronic obstructive...

To study the correlation between the inflammatory mediators released by alveolar macrophages and the pulmonary ventilatory capacity in patients with chronic obstructive pulmonary disease (COPD).

Alveolar macrophages were collected by fiberoptic bronchoscopy from 8 patients with chronic bronchitis, 8 with COPD with a forced expiratory volume in one second (FEV(1)) < or = 70%, and 8 healthy nonsmokers. All patients were in the stable stage. The macrophages were cultured and stimulated with lipopolysaccharide (LPS, 10 microg/ml). IL-8, IL-1 beta, TNF-alpha and IL-6 in the supernatants were measured by ELISA. Pulmonary functions were tested in all three groups. The correlation between different cytokines was tested with Pearson's relevant analysis, and the correlation between lung functions and cytokines was tested with multiple reverse regression analysis.

(1) The concentrations of IL-8 released from macrophages in the COPD group were (43 +/- 27) microg/L and (57 +/- 41) microg/L (with LPS), higher than those from healthy controls [(13 +/- 10) microg/L and (20 +/- 13) microg/L] (P < 0.05), but not different from those in patients with chronic bronchitis [(29 +/- 21) microg/L and (32 +/- 23) microg/L] (P > 0.05). (2) The concentrations of IL-1 beta released from macrophages in the COPD group, the chronic bronchitis group and the control group were [(50 +/- 41) ng/L, (94 +/- 59) ng/L, (37 +/- 32) ng/L] before LPS, and [(225 +/- 108) ng/L, (153 +/- 175) ng/L, (70 +/- 37) ng/L] after LPS stimulation, which were positively correlated with the concentrations of IL-8 (P < 0.05). The concentrations of TNF-alpha released from macrophages in three groups were [(1,238 +/- 679) ng/L, (3,088 +/- 2,879) ng/L and (1,332 +/- 1,846)ng/L], which were positively correlated with the concentrations of IL-1 beta (P < 0.05). The concentrations of IL-6 released from macrophages in the three groups were [(7,959 +/- 8,458) ng/L, (5,317 +/- 10,112) ng/L and (6,480 +/- 4,982) ng/L, which were positively correlated with the concentrations of IL-8 (P < 0.05). (3) The values of FEV(1)/FVC, V(max50) and V(max25) measured in the COPD group were [(65.1 +/- 5.3)%, (43 +/- 8)% and (37 +/- 11)%, respectively, which were negatively correlated with the concentrations of IL-8 (P < 0.05), but negatively correlated with the concentrations of IL-1 beta only in the presence of LPS (P < 0.05).

IL-8 released by alveolar macrophages plays an important role in the process from chronic cough to chronic airflow obstruction. TNF-alpha, IL-1 beta and IL-6 released by alveolar macrophages are also involved in the airway inflammation in COPD.