Asthma, rhinitis, other respiratory diseasesA comparison of exhaled nitric oxide and induced sputum as markers of airway inflammation☆
Section snippets
Subjects
One hundred thirty-one adult subjects were recruited from patients attending the Firestone Regional Chest and Allergy Clinic and by advertisement (Table I). There were 5 groups. Healthy subjects had no symptoms, an FEV1/vital capacity (VC) of 70% or greater, and a methacholine PC20 of greater than 16 mg/mL and were divided into those with and without atopy on the basis of positive skin prick test results to one or more common allergen extracts. Asthma was identified by the presence of symptoms
Results
We compared ENO levels and sputum cell counts in subjects with asthma, subjects with eosinophilic bronchitis without asthma, and healthy subjects (Tables I and II). There were significant differences in ENO levels, eosinophil percentages, absolute eosinophil counts (×106/g; P < .001), macrophage percentages (P = .023), and lymphocyte percentages (P = .001) between the groups, as well as for FEV1 percent predicted, FEV1/SVC, and PC20 (P < .001).
Discussion
The results of this cross-sectional study show weak correlations between ENO and sputum eosinophils in atopic healthy and asthmatic subjects taking and not taking steroids. Lower levels of ENO than would be expected from the degree of sputum eosinophilia and airway narrowing were found in subjects treated with steroids. High levels of ENO were found in some normal and asthmatic subjects with normal sputum eosinophils. ENO measurement was capable of distinguishing subjects with asthma from
Acknowledgements
We thank Dr P. Silkoff, Mr H. Furlott, and Mr D. McCormack for their assistance in setting up the ENO analyser; Ms S. Carruthers and Ms S. Weston for performance of the sputum cell counts; and Drs J. Belda, R. Leigh, and C. Lemière for the characterization of the study subjects.
References (35)
- et al.
Chronic cough: eosinophilic bronchitis without asthma
Lancet
(1989) - et al.
Non-eosinophilic corticosteroid unresponsive asthma
Lancet
(1999) - et al.
Increased formation of the potent oxidant peroxynitrite in the airways of asthmatic patients is associated with induction of nitric oxide synthase: effect of inhaled glucocorticoid
FASEB J
(1998) - et al.
Increased nitric oxide in exhaled air of normal subjects with upper respiratory tract infections
Eur Respir J
(1995) - et al.
Elevated levels of NO in bronchiectasis
Am J Respir Crit Care Med
(1995) - et al.
Exhaled nitric oxide in human lung transplantation. A noninvasive marker of acute rejection
Am J Respir Crit Care Med
(1998) - et al.
Marked flow dependence of exhaled nitric oxide using a new technique to exclude nasal nitric oxide
Am J Respir Crit Care Med
(1997) - et al.
Exhaled and nasal nitric oxide measurements: recommendations
Eur Respir J
(1997) - et al.
Exhaled nitric oxide: a new lung function test
Thorax
(1996) - et al.
Exhaled nitric oxide correlates with airway hyperrresponsiveness in steroid-naive patients with mild asthma
Am J Respir Crit Care Med
(1998)
Changes in the dose of inhaled steroid affect exhaled nitric oxide levels in asthmatic patients
Eur Respir J
Increase in exhaled nitric oxide levels in patients with difficult asthma and correlation with symptoms and disease severity despite treatment with oral and inhaled corticosteroids
Thorax
Correlation between exhaled nitric oxide, sputum eosinophils, and methacholine repomsiveness in patients with mild asthma
Thorax
Effect of inhaled steroids on airway hyperresponsiveness, sputum eosinophils, and exhaled nitric oxide levels in patients with asthma
Thorax
Effect of inhaled budesonide on lung function and airway inflammation. Assessment by various inflammatory markers in mild asthma
Am J Respir Crit Care Med
Induced sputum cell counts in healthy adults
Am J Respir Crit Care Med
Reduced endogenous nitric oxide in the exhaled air of smokers and hypertensives
Eur Respir J
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Reprint requests: Frederick E. Hargreave, MD, Firestone Regional Chest and Allergy Unit, St Joseph’s Hospital, 50 Charlton Ave East, Hamilton, Ontario, Canada L8N 4A6.