Studies have reported high levels of fractional exhaled nitric oxide (FeNO) in atopic patients, particularly in asthmatics, suggesting that FeNO is a marker of bronchial inflammation.Is the FeNO elevation specific to bronchial inflammation?
It does not look so.
In a Dutch study of 361 participants, FeNO was higher in those with eczema, allergic rhinitis, smokers and atopic sensitization.
This finding implies that FeNO elevation in asthma may be nonspecific and influenced by atopic disease outside the lungs.
NO is synthesized from L-arginine by the enzyme nitric oxide synthase (NOS). Measuring exhaled nitric oxide (FeNO) can serve as a marker of airway inflammation because levels increase in asthma exacerbation and decrease with corticosteroid therapy.
Inflammation in asthma (mind map). FeNO is a marker of oxidative stress. See more Allergy and Immunology mind maps here.
Active and passive smoking decreased FeNO levels in adults.
References:
Atopic disease and exhaled nitric oxide in an unselected population of young adults. Annals of Allergy, Asthma and Immunology, 2008, vol. 100, no. 1, pp. 59 - 65.
Exhaled nitric oxide (FeNO) in asthma and sinusitis. AllergyNotes.
References:
Atopic disease and exhaled nitric oxide in an unselected population of young adults. Annals of Allergy, Asthma and Immunology, 2008, vol. 100, no. 1, pp. 59 - 65.
Exhaled nitric oxide (FeNO) in asthma and sinusitis. AllergyNotes.
Exhaled nitric oxide correlated with control in recurrent infantile wheeze treated with inhaled corticosteroids. http://goo.gl/AS7I
Image source: Wikipedia.
Image source: Wikipedia.