Study On Airway Inflammation In Acute Exacerbation Of Chronic Obstructive Pulmonary Disease And Relationship Between The Inflammation And The Lung Function

Objective: To investigate the activities of inflammatory cells and cytokines in acute exacerbation of chronic obstructive pulmonary disease and the relationship between the inflammation and the lung function.Methods: Sputum was induced by inhalation of 4.5% hypertonic saline solution delivered by an ultrasonic nebulizer device. Induced sputum was collected from patients during acute COPD exacerbation and normal subjects. Lung function was carefully monitored by spirometry. Inflammatory cells of sputum were counted and the concentration of interleukin-5(IL-5) and tumor necrosis factor-a(TNF-a) was measured by ELISA.Results: The numbers of total cells, neutrophils and eosinophils in sputum in AECOPD group were significantly higher than those in control group (P<0.01). AECOPD patients have higher concentration of TNF-a in induced sputum compared with normal subjects(P<0.01). There was no increase in sputum level of IL-5 during exacerbations of COPD compared with normal subjects(P=0.14). In the AECOPD group, the number of neutrophils is correlated negatively with FEV₁% and FEV₁/FVC(r=-0.735, -0.807 respectively) and correlated positively with the concentration of TNF-a(r=0.647, P<0.01). There was a negative correlation between the concentration of TNF-a in sputum and FEV₁% and FEV₁/FVC(r=-0.629, -0.749, respectively, P<0.01).In contrast, the number of eosinophils is not associated with the lung function and the concentration of IL-5.Conclusion: Neutrophils and TNF-a are involved in the airway inflammation of AECOPD patients and play an important role in the exacerbation of the lung function. There was a positive correlation between the concentration of TNF-a and...