In order to characterize intraluminal airway inflammation in subjects with chronic bronchitis, bronchoscopy and bronchoalveolar lavage were performed in 28 subjects with chronic bronchitis with fixed airway obstruction and, for comparison, 15 asymptomatic smokers and 25 normal nonsmoking volunteers. The chronic bronchitics had a cough productive of sputum on most days of the month for 6 months in the preceding 2 yr, had at least one exacerbation requiring medical intervention in each of the previous 2 yr, and had an FEV1 <76% of predicted without response to bronchodilator. During bronchoscopy the airways were assessed for visual evidence of inflammation by assigning them a score, the bronchitis index, that graded the airways according to the apparent severity of airway edema, erythema, friability, and secretion. Bronchoalveolar lavage was performed by sequentially instilling and retrieving with gentle suction five 20-ml aliquots of sterile normal saline into each of three separate lobes. The first aliquots, the 'bronchial' sample, were pooled and processed separately from the final four aliquots, the 'distal' sample. Cell counts, cell differentials, and albumin were determined for both the bronchial and distal samples. In order to correlate inflammation with clinical parameters, sputum was collected for 24 hr prior to bronchoscopy; spirometry was performed just prior to bronchoscopy, and smoking histories were obtained. Visual inspection of the airways, as quantified by the bronchitis index, demonstrated significantly more evidence for inflammation in the chronic bronchitics than in either the asymptomatic smokers or the normal subjects. The bronchial sample lavage fluids from the chronic bronchitics tended to contain more cells (6.1 ± 2.2 x 106 cells) than the bronchial sample fluids from the asymptomatic smokers (3.6 ± 0.6 x 106 cells) or normal subjects (3.7 ± 0.5 x 106 cells). Furthermore, the chronic bronchitics had a higher percentage of neutrophils in their bronchial lavage fluid (35.8 ± 5.6%) than did either the asymptomatic smokers (20.7 ± 2.6%, p = 0.0001) or the normal subjects (10.3 ± 5.6%). The distal sample lavage fluid also recovered more neutrophils from both the chronic bronchitics (15.0 ± 4.2%, p = 0.0012) and asymptomatic smokers (5.7 ± 1.3%, p = 0.002) than from the normal subjects (2.8 ± 0.4%). The chronic bronchitics were divided into two groups: those with low (<20%) and those with high (>20%) bronchial sample neutrophils. Those with higher bronchial sample neutrophils had significantly more sputum production and lover FEV1, FEV1/FVC, and FEF25-75 than did the subjects with lower bronchial sample neutrophils. Furthermore, among the chronic bronchitics, quantitatiion of airway neutrophils correlated with pack-years of cigarett smoked (r2 = 0.65, p < 0.001). Thus, chronic bronchitis is associated with intraluminal airway neutrophilia. Furthermore, in this group of chronic bronchitics, airway neutrophils correlated with sputum production and airway obstruction.
ASJC Scopus subject areas
- Pulmonary and Respiratory Medicine