Asthma is a common inflammatory respiratory disease affecting 11% of Canadians, but its diagnosis remains challenging, leading to delays in treatment or overtreatment. Spirometry with a reversibility test and bronchial provocation testing (BPT), considered the gold standard, are the reference diagnostic methods. However, access to BPT is limited as it is performed in hospital settings.
Type 2 inflammation biomarkers, the fractional exhaled nitric oxide (FeNO) and blood eosinophils (EOS), represent a potential alternative. In addition to their prognostic and theragnostic value, these markers predict a good response to inhaled corticosteroids in individuals aged ≥ 6 years with asthma. However, their use remains restricted to pulmonologists in specialized clinics and is not recommended as a diagnostic tool in Quebec.
Despite studies demonstrating their diagnostic value in specialized settings, these tests remain underexplored in primary care and insufficiently studied in children under 12 years.
The objective of ou study is to evaluate the relevance and performance of FeNO and blood eosinophils in the diagnosis of asthma in children referred in primary care with non-diagnostic spirometry.
Individuals aged 6 to <18 years, presenting symptoms suggestive of asthma
Patients referred for a methacholine bronchial provocation test by primary care (defined as non-pulmonologist, non-ENT specialist, non-allergist)
Spirometry inconclusive
Use of an inhaled or systemic corticosteroid in the previous 48 hours;
Smoking in the previous 6 hours; history of viral and/or bacterial respiratory infection in the past 4 weeks;
major cardiopulmonary disease, including: a) chronic obstructive pulmonary disease (COPD), defined by all of the following: i) aged ≥ 40 years , ii) permanent obstruction on spirometry (FEV1/FVC <0.7) and iii) a smoking history of >10 pack-years or known alpha-1-antitrypsin deficiency, b) lung conditions deemed significant by the investigator, including cystic fibrosis and bronchiectasis, and c) unstable heart disease.
Université de Sherbrooke
Lead sponsor
Association Pulmonaire du Quebec
Collaborator
Fonds de la Recherche en Santé du Québec
Collaborator
Fondation JA DeSève
Collaborator
Opération Enfant Soleil
Collaborator