Using blood eosinophils and exhaled nitric oxide to diagnose asthma

Diagnostic and Translational Values of Point-of-care Blood Eosinophils and Exhaled Nitric Oxide (FeNO) in People Referred by Primary Care for Suspected Asthma (DIVE)

Observational Université de Sherbrooke · NCT05992519

This study is testing if measuring blood eosinophils and exhaled nitric oxide can help doctors diagnose asthma in patients who might have it but haven't had clear test results.

Quick facts

Study typeObservational
Enrollment123 (estimated)
Ages12 Years and up
SexAll
SponsorUniversité de Sherbrooke Academic / other
Locations1 site (Sherbrooke, Quebec)
Trial IDNCT05992519 on ClinicalTrials.gov

What this trial studies

This study aims to validate the diagnostic performance of blood eosinophils and exhaled nitric oxide (FeNO) as biomarkers for asthma in patients referred by primary care with suspected asthma and non-diagnostic spirometry results. By focusing on these biomarkers, the study seeks to provide early insights into airway inflammation and identify patients who are most likely to benefit from anti-inflammatory therapies. The approach is designed to improve access to effective asthma diagnosis and management, particularly in children and those with limited access to specialized testing. The study will also explore inflammatory proteins in nasal epithelial lining fluid to enhance understanding of asthma mechanisms.

Who should consider this trial

Good fit: Ideal candidates are individuals aged 12 years and older who exhibit symptoms suggestive of asthma and have non-diagnostic spirometry results.

Not a fit: Patients with recent use of corticosteroids, smoking history, or major cardiopulmonary diseases may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could lead to quicker and more accurate asthma diagnoses, allowing for timely and appropriate treatment.

How similar studies have performed: Other studies have shown promising results using similar biomarker approaches for asthma diagnosis, indicating potential for success in this study.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* aged ≥ 12 years who have symptoms suggestive of asthma,
* referred by their primary care provider (defined as a non-respirologist, non-allergist, non-otolaryngologist) using the CHUS suspected asthma decision-making algorithm. Under that algorithm, patients have non-diagnostic pre- and post-bronchodilator spirometry and no contraindications to a methacholine challenge.
* Free and informed consent must be given by the patient (and their legal guardian, if applicable).

Exclusion Criteria:

* 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.

Where this trial is running

Sherbrooke, Quebec

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions AsthmaAsthma in ChildrenDiagnosisInflammation
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.