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

NCT05992519 | Completed

• 1 other identifier: 2023-4791
• Study Type: observational
• Target: 123
• Locations: 1 country
• Sites: 1

Brief Summary

Asthma is characterised by episodic symptoms (attacks) caused by airway inflammation and decreased airflow to the lungs. It affects 10% of the Canadian population and is the most common chronic disease in childhood. Despite its burden and its potential to be life-threatening, establishing the diagnosis takes time due to difficulty in accessing specialised breathing tests. Indeed, the current diagnostic strategy relies on a breathing test (spirometry) and, if non-diagnostic, a subsequent more complicated breathing test conducted in hospitals (a bronchial provocation test). Our dependence on the latter test must be confronted to the bottleneck created by our reliance on it and the difficulty to do these tests in children. Furthermore, within the current framework, people receiving a diagnosis do not know if they have active airway inflammation - a key feature with predicts increased susceptibility to asthma attacks and treatment responsiveness. Our study's goal is to validate clinically accessible and useful diagnostic tests for peoplesuspected to have asthma. Specifically, we are interested in alternative tests that are a) achievable outside the hospital; b) useful markers of airway inflammation/risk c) can identify people at with a higher likelihood of responding to anti-inflammatory therapy. The two tests we are mainly interested in are:

• Exhaled nitric oxide (measured with a portable handheld machine)
• The blood eosinophil count (obtained on a general blood test) +/- Other tests which we might be able to develop within this cohort (e.g. urine tests)

Conditions

Asthma; Asthma in Children; Diagnosis; Inflammation

Outcome Measures

Primary Outcomes (3)

• AUC of the ROC analysis to diagnose asthma

  Diagnosis of asthma defined as a methacholine PD20 \< 200 mcg

  FeNO measured on the day of the methacholine challenge (i.e. Baseline visit)

• Blood eosinophil count: ROC analysis AUC to diagnose asthma

  Diagnosis of asthma defined as a methacholine PD20 \< 200 mcg

  Blood eosinophils measured on the day of the methacholine challenge (i.e. Baseline visit)

• Combination of FeNO + Blood eosinophil count: ROC analysis AUC to diagnose asthma

  Diagnosis of asthma defined as a methacholine PD20 \< 200 mcg

  FeNO and blood eosinophils measured on the day of the methacholine challenge (i.e. Baseline visit)

Secondary Outcomes (3)

• Univariate association between biomarkers (blood eosinophils and FeNO) and inflammatory proteins/metabolites

  Baseline

• Operational efficacy of the use of biomarkers as a diagnostic tool:

  Baseline

• Biomarker level in asthmatic patients at time of diagnosis

  Baseline

Study Arms (1)

People suspected with asthma

Patients will receive an in invitation letter at the time of BPT scheduling. In the week proceeding the test, the clinical inhalation therapist will discuss the project and schedule the study visit on the day of the BPT. The study visit will be done prior to BPT whenever possible. Baseline visit: * Medical history * 5-item Asthma Control Questionnaire (ACQ-5) * FeNO measurement (NIOX VERO device) * Nasosorption for nasal epithelial lining fluid (NELF) biobanking * blood tests (complete blood count with differential, C-reactive protein, total and specific serum immunoglobulin E, biobank) * urine sample (biobank)

Diagnostic Test: ¸FeNO

Interventions

¸FeNO DIAGNOSTIC_TEST

FeNO measured with a NIOX VERO device after the methacholine challenge

People suspected with asthma

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Probability Sample

Study Population

The study has a collaboration agreement with the respiratory physiology service. In this context, a research invitation letter will be sent with confirmation of the appointment. The letter indicates that participation is voluntary and provides the expected length of the appointment (20-30 minutes), a QR code referring them to an online version of the Information and Consent Form (ICF), and a cell phone number and email address for the research team, with a phone number for individuals to state their refusal to be contacted. In the week preceeding the challenge, the clinical inhalation therapist will call non-objecting pre-screened patients to discuss the project and plan the study visit.

You may qualify if:

• 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).

You may not qualify if:

• 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.

Sponsors & Collaborators

• Université de Sherbrooke: lead
• Association Pulmonaire du Quebec: collaborator
• Réseau de Recherche en Santé Respiratoire du Québec: collaborator
• AstraZeneca: collaborator
• Fonds de la Recherche en Santé du Québec: collaborator
• Fondation JA DeSève: collaborator

Study Sites (1)

Centre de Recherche du CHUS

Sherbrooke, Quebec, J1H5N4, Canada

Location

Related Publications (1)

• Gronnier M, Desy L, Pouliot L, Lemieux SE, Vezina FA, Lachapelle P, Counil FP, Duval M, Cliche D, Lemaire-Paquette S, Coulibaly L, Hudon C, Lands LC, Ducharme FM, Tse S, Couillard S. Integrating blood eosinophils and exhaled nitric oxide (FeNO) in asthma diagnostic pathways for adults and children: the PROPULSION SANTE observational study with translational sub-studies (DIVE, DIVE2)-protocols. BMJ Open Respir Res. 2025 Nov 27;12(1):e003750. doi: 10.1136/bmjresp-2025-003750.

  PMID: 41314665 DERIVED

Biospecimen

Retention: SAMPLES WITHOUT DNA

Serum, plasma, whole blood Nasosorption for NELF (nasal epithelial lining fluid) Urine sample

MeSH Terms

Conditions

Asthma; Disease; Inflammation

Condition Hierarchy (Ancestors)

Bronchial Diseases; Respiratory Tract Diseases; Lung Diseases, Obstructive; Lung Diseases; Respiratory Hypersensitivity; Hypersensitivity, Immediate; Hypersensitivity; Immune System Diseases; Pathologic Processes; Pathological Conditions, Signs and Symptoms

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: August 7, 2023
• First Posted: August 15, 2023
• Study Start: November 7, 2022
• Primary Completion: October 30, 2025
• Study Completion: October 31, 2025
• Last Updated: November 19, 2025

Record last verified: 2025-05

Locations

CA (1)