Clinical aspects of exhaled nitric oxide

Abstract

There has been intense research into the role nitric oxide (NO) plays in physiological and pathological mechanisms and its clinical significance in respiratory medicine.Elevated levels of exhaled levels of exhaled NO in asthma and other inflammatory lung diseases lead to many studies examining NO as potential markers of airway inflammation, enabling repeated noninvasive and standardized monitoring of airway inflammation. In airway inflammation, NO is not merely a marker but may have antiinflammatory and pro-inflammatory effects. Significant correlation has been found between exhaled NO and skin test scores in steroid naive asthmatic patients, allowing to discriminate patients with and without airway responsiveness. Exhaled NO is significantly elevated in acute asthma, or steroid-resistant severe asthma, or when the maintenance dose of inhaled steroids is reduced, and quickly reduced down to the levels in patients with stable asthma after steroid treatment. Exhaled NO has been successfully used to monitor anti-inflammatory treatment with inhaled corticosteroids in asthma. Exhaled NO is extremely sensitive and rapid marker of the dose-dependent effect of steroid treatment, or asthma deterioration, which is increased to any changes in lung function, provocative concentration causing a 20% fall in forced expiratory volume, sputum eosinophilia or asthma symptoms. Exhaled NO is not increased in stable chronic obstructive pulmonary disease (COPD), but patients with unstable COPD, or bronchiectasis have high NO levels. Exhaled and nasal NO are diagnostically low in cystic fibrosis and primary pulmonary dyskinesia.Analysis of exhaled air, including nitric oxide, is feasible and could provide a noninvasive method for use in monitoring and management of lung diseases. Eur Respir J 2000; 16: 781±792.

The effect of adiposity measured by dual-energy X-ray absorptiometry on lung function

“…Inclusion criteria were being healthy and 20-50 yrs of age. To decrease the likelihood of subclinical airways disease, exclusion criteria were: current respiratory symptoms; history of respiratory disease; ex-smokers with a smoking history of .10 pack-yrs or who had smoked in the last year; cardiac or neurological comorbidity; structural abnormalities of the chest wall; and an exhaled nitric oxide concentration of .35 ppb [15] or a positive methacholine challenge [16]. The study was approved by the Lower South Ethics Committee (Dunedin, New Zealand) and all participants gave written informed consent.…”

Respiratory symptoms, lung functions, and exhaled nitric oxide (FENO) in two types of fish processing workers: Russian trawler fishermen and Norwegian salmon industry workers

“…Further analysis revealed that asthmatic trawler workers had substantially higher FE NO levels compared to asthmatic salmon workers (males). Fractional exhaled nitric oxide is thought to reflect eosinophilic inflammation [33][34][35] and behaves as a biomarker of ''allergic asthma'' phenotype rather than asthma itself. The higher FE NO levels in trawler workers could accordingly point to a greater influence of allergic mechanisms among these workers.…”

Laser-induced fluorescence spectroscopy of14N18O and its application to breath analysis

“…Plants utilise NO as a multifarious signal molecule in growth and differentiation processes [6][7][8]. Concentration measurement of exhaled NO is a well-established procedure for monitoring inflammatory diseases such as asthma [9,10]. Commercial detection devices achieve detection limits of about 1 parts per billion (ppb), but are not able to differentiate between isotopologues.…”