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Published on: January 21, 2018
Changes in exhaled nitric oxide levels after bronchial allergen challenge
María Pedrosa1, Pilar Barranco, Valentín López-Carrasco
1Department of Allergy, Hospital La Paz Health Research Institute, IdiPAZ, Madrid, Spain. m.pedrosa.d@gmail.com
Fractional exhaled nitric oxide (FeNO) effectively monitors airway inflammation during allergen challenges in asthma patients. A 12% increase in FeNO post-challenge accurately predicts positive asthmatic reactions, aiding in diagnosis.
Area of Science:
- Respiratory Medicine
- Allergy and Immunology
- Pulmonary Physiology
Background:
- Fractional exhaled nitric oxide (FeNO) indicates airway inflammation in asthma.
- Allergen exposure can lead to delayed FeNO elevation.
- Bronchial allergen challenge (BAC) is used to assess asthma responses.
Purpose of the Study:
- To evaluate airway inflammation using FeNO during BAC.
- To determine the diagnostic performance of FeNO changes following allergen exposure.
Main Methods:
- 34 asthma patients with allergen sensitization underwent BAC.
- FeNO was measured pre-challenge and 24 hours post-challenge.
- Receiver operating characteristic curves analyzed FeNO change sensitivity and specificity.
Main Results:
- 61.76% of patients showed a positive asthmatic reaction (responders).
- Responders exhibited a significant FeNO increase (median 14.0 ppb) vs. non-responders (-1.0 ppb).
- A 12% FeNO increase cutoff showed 0.81 sensitivity and 0.92 specificity for positive BAC outcomes.
Conclusions:
- FeNO measurements serve as a reliable surrogate for airway inflammation post-BAC.
- FeNO is a valuable tool for monitoring and interpreting allergen-induced bronchial challenge tests.
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