To examine the nature and the degree of airway inflammation in chronic bronchitis during exacerbations, bronchial biopsies and sputum were obtained in 11 subjects with chronic bronchitis examined during an exacerbation, and in 12 subjects with chronic bronchitis examined under baseline conditions. All subjects were nonatopic. Lobar bronchial biopsies were assessed using histochemical and immunohistochemical techniques, and sputum was examined for differential cell counts of leukocytes. Subjects with bronchitis during exacerbations had, on average, 30-fold more eosinophils in their bronchial biopsies than did those examined under baseline conditions (p < 0.001). Although to a lesser extent, the numbers of neutrophils (p < 0.01), T-lymphocytes (CD3) (p < 0.05), VLA-1-positive cells (p < 0.01), and TNF-alpha positive cells (p < 0.05) were also increased during exacerbations. By contrast, the T-lymphocyte subpopulations (CD4 and CD8) and the numbers of macrophages, mast cells, IL-2R-positive cells, and IL-1 beta-positive cells were similar in the two groups of subjects, as well as the percentages of ICAM-1- and E-selectin-positive vessels. Eosinophils were also increased in sputum of subjects with exacerbations when compared with those examined under baseline conditions (p < 0.05). In conclusion, exacerbations of chronic bronchitis are associated with a marked airway eosinophilia and with a milder increase in the number of neutrophils, activated T-lymphocytes, and TNF-alpha-positive cells in the bronchial mucosa.

To determine the relationship between inflammatory cells in sputum, bronchoalveolar lavage (BAL), and bronchial mucosa, we counted the number of leukocytes in sputum, BAL, and bronchial biopsies obtained from subjects with asthma and with chronic bronchitis in stable condition or during exacerbations. Sputum was induced by inhalation of hypertonic saline in the asthma group. Spontaneous sputum was collected in the chronic bronchitis groups. Differential counts of leukocytes were performed on cytospin preparations of sputum and BAL. Eosinophils, macrophages, neutrophils, and lymphocytes were quantified in the submucosa of the bronchial biopsies. In asthma and in stable chronic bronchitis, the percentages of neutrophils were significantly higher in sputum than in BAL, whereas the opposite was true of the percentages of macrophages and lymphocytes. The lymphocyte was the predominant cell infiltrating the bronchial submucosa in all groups. BAL eosinophils correlated with submucosal and sputum eosinophils in the asthma and exacerbated chronic bronchitis groups. A similar trend was observed between submucosal and sputum eosinophils. In conclusion, the relative proportion of inflammatory cells was different in sputum, BAL, and bronchial mucosa. However, there was a fairly good agreement between the number of eosinophils counted with the three techniques in asthmatics and in exacerbated chronic bronchitics, suggesting that sputum cell analysis may be used for a noninvasive assessment of airway eosinophilia.

To determine whether adhesion molecules and cytokines are upregulated in the bronchial mucosa of chronic bronchitics, we obtained bronchial biopsies in 16 chronic bronchitics, in eight asymptomatic smokers, and in seven normal nonsmoking subjects. Bronchial biopsies were examined by immunohistochemistry to identify the expression of E-selectin and intercellular adhesion molecular-1 (ICAM-1) on vessels and on bronchial epithelium, and the expression of interleukin-1 beta (IL-1 beta), tumor necrosis factor-alpha (TNF-alpha), neutrophil elastase, and eosinophil cationic protein (EG-2) on cells in the submucosa. Chronic bronchitics had an increased number of E-selectin-positive vessels when compared with both asymptomatic smokers (p < 0.05) and normal subjects (p < 0.01). The numbers of ICAM-1-positive vessels, neutrophils, and IL-1 beta, TNF-alpha-, and EG-2-positive cells were not significantly different in the three groups of subjects examined. When the bronchitic group was divided according to the presence or absence of airway obstruction, the increased number of E-selectin-positive vessels persisted only in bronchitics with airway obstruction, who also had an increased expression of ICAM-1 on basal epithelial cells. We concluded that in the bronchial mucosa of chronic bronchitics with airway obstruction, there is an increased expression of E-selectin on vessels and of ICAM-1 on basal epithelial cells, suggesting the involvement of these adhesion molecules in the pathogenesis of the disease.

To investigate the effect of smoking cessation on the airway inflammatory process present in nonatopic subjects with chronic bronchitis, we obtained bronchial biopsies from nine current smokers and seven exsmokers, all with symptoms of chronic bronchitis at the time of the study, and from seven healthy nonsmoking subjects. The exsmokers had stopped smoking on average 13 yr before the study, yet cough and production of sputum had persisted. Bronchial biopsies were assessed using immunohistochemical techniques to investigate the number of inflammatory cells, the markers of mononuclear cell activation, and the expression of endothelial adhesion molecules and cytokines in the subepithelium. Current smokers and exsmokers had an increased number of macrophages, IL-2R-positive cells, VLA-1-positive cells, ICAM-1-positive vessels, and E-selectin-positive vessels compared with normal nonsmoking subjects, but the number of cells positive for neutrophils, EG-2, CD3, CD4, CD8, TNF-alpha and IL-1 beta were similar among the three groups. No differences were observed between current smokers and exsmokers for any parameter examined. In conclusion, the inflammatory process present in the airway mucosa of current smokers may persist after smoking cessation in subjects who continue to have symptoms of chronic bronchitis.

To investigate whether the airway inflammatory process is different in patients with chronic bronchitis with airflow limitation and those with chronic bronchitis without airflow limitation, we obtained bronchial biopsies from 14 subjects with chronic sputum production and fixed airway obstruction, and from 10 subjects with chronic sputum production and normal FEV1, all with a history of cigarette smoking. Paraffin-embedded and frozen bronchial biopsies were examined by immunohistochemistry to identify the number of neutrophils (neutrophil-elastase), eosinophils (antieosinophil cationic protein [EG-2]), mast cells (tryptase), T-lymphocytes (CD3), T-lymphocyte subpopulations (CD4 and CD8), B-lymphocytes, and macrophages (CD68) in the submucosa. Subjects with chronic bronchitis with airflow limitation had a greater number of T-lymphocytes (p < 0.01) and macrophages (p < 0.05) than subjects with chronic bronchitis without airflow limitation, whereas the T-lymphocyte subpopulations and the numbers of B-lymphocytes, neutrophils, eosinophils, and mast cells were similar in the two groups. When all the subjects were considered together, the number of T-lymphocytes correlated inversely with the values of FEV1 (r = 0.46, p < 0.02). In conclusion, airflow limitation in subjects with chronic bronchitis is associated with an increased number of T-lymphocytes and macrophages in the bronchial mucosa.