Related Experiment Video
Updated: Apr 30, 2026

Generation of a Chronic Obstructive Pulmonary Disease Model in Mice by Repeated Ozone Exposure
Published on: August 25, 2017
Exhaled nitric oxide predicts eosinophilic airway inflammation in COPD
Kun-Ta Chou1, Kang-Cheng Su, Shiang-Fen Huang
1Department of Chest Medicine, Taipei Veterans General Hospital, No. 201, Sec. 2, Shi-Pai Road, Taipei, 112, Taiwan.
Purpose:
Chronic obstructive pulmonary disease (COPD) with eosinophilic airway inflammation may represent a unique phenotype, possibly with shared features of COPD and asthma. The role of exhaled nitric oxide (eNO) in identifying COPD patients with sputum eosinophilia was examined in this study.
Methods:
Ninety COPD patients without past medical history of asthma or allergic diseases were prospectively enrolled, and their eNO, lung function, and cellular profile of induced sputum were measured. Eosinophil cationic protein and IgE in sputum and venous blood also were determined. Subjects with and without sputum eosinophilia (>3 %) were compared. The role of eNO in the prediction of sputum eosinophilia was assessed in a logistic regression model.
Results:
Patients with sputum eosinophilia had significantly higher levels of eNO (29 vs. 18 ppb, p = 0.01) than those without. The difference in serum total IgE (168 vs. 84.9 IU/ml, p = 0.057) and percentages of positive allergen test results (48.3 vs. 29.5 %, p = 0.082) showed a trend toward significance. The sputum eosinophil level was significantly correlated to the eNO level (r = 0.485, p < 0.001). The eNO level at the cutoff of 23.5 ppb had the maximum sum of sensitivity (62.1 %) and specificity (70.5 %). The unadjusted and adjusted odds ratios of a higher eNO level (>23.5 ppb) in the prediction of sputum eosinophilia were 3.909 (confidence interval (CI) 1.542-9.91, p = 0.004) and 4.329 (CI 1.306-14.356, p = 0.017), respectively.
Conclusions:
eNO is a good marker to identify COPD patients with eosinophilic airway inflammation.
Related Concept Videos
Chronic Obstructive Pulmonary Disease III: Chronic Bronchitis Features
Asthma I: Introduction
Chronic Obstructive Pulmonary Disease-II: Pathophysiology
Chronic Inflammation
Chronic Obstructive Pulmonary Disease I: Introduction
Chronic Obstructive Pulmonary Disease II: Emphysema
COPD: Pathogenesis and Clinical Features
The primary cause for the onset of COPD is cigarette smoking and exposure to air pollution. These hazardous factors initiate a chain reaction within the lungs, resulting in chronic inflammation, damage to the airways, and a...

