The Asthma Bronchial Challenge Study

Bronchial Challenge Testing in Asthma: The Effect of Mannitol Dry Powder Inhalation on Volatile Organic Compounds in Exhaled Breath

Status

Completed

Phases

Unknown

Study type

Observational

Source

ClinicalTrials.gov

Registry ID

NCT03575663

Acronym

ABC

Enrollment

Registered

2018-07-02

Start date

2018-04-25

Completion date

2019-02-28

Last updated

2019-04-25

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Asthma

Keywords

Breathomics, Metabolomics, Exhaled breath test, Biomarker

Brief summary

This is a randomised, controlled, cross-over study to determine the effect of indirect bronchial challenge testing upon volatile organic compounds (VOCs) in the exhaled breath of adults with well-controlled, mild-to-moderate asthma. Participants will undergo baseline evaluation including clinical history, spirometry, exhaled nitric oxide measurement (FeNO), phlebotomy (blood eosinophil count), and sampling of exhaled breath VOCs. Participants will be randomised to receive either an indirect bronchial challenge test using mannitol dry powder (MDP) or a sham bronchial challenge, followed by further sampling of breath VOCs. The study will consist of a consent visit and two assessment visits with participants allocated to receive one of the two challenges (MDP or sham) at each assessment. Data will be analysed to determine the effect of bronchial challenge upon exhaled breath VOC profiles.

Interventions

DIAGNOSTIC_TESTIndirect bronchial challenge

Mannitol dry powder inhalation

OTHERSham bronchial challenge

Mock dry powder inhalation

Study design

Observational model

CASE_CROSSOVER

Time perspective

PROSPECTIVE

Eligibility

Sex/Gender

ALL

Age

18 Years to No maximum

Healthy volunteers

Yes

Inclusion criteria

* Male or female * Aged 18 or over * Able to provide informed consent * Self-report of asthma diagnosis from health professional * Diagnostic confirmation meeting British Thoracic Society guidelines will be sought from primary care * Non-smokers; or ex-smokers of at least two years duration with less than a ten pack year history * Asthma Control Questionnaire score \< 1.0 * Asthma treated according to level-1 to level-2 of British Thoracic Society treatment guidelines

Exclusion criteria

* Respiratory tract infection, asthma exacerbation or change in treatment step within the previous four weeks * Major chronic cardiorespiratory disease other than asthma * Significant comorbid condition * Condition that may be compromised by repeated spirometry manoeuvres or induced bronchospasm * Asthma Control Questionnaire score \>1.0 * Asthma treated at level 3 of the treatment guidelines or higher * Pregnant or nursing mothers * Current smokers or 'vapers' * Ex-smokers of \< 2 years duration or \> 10 pack years. * Participating in a clinical trial of an investigational medicinal product (CTIMP). * Unable to speak English. * Low baseline lung function (FEV1 \<1.50 litres or \< 70% predicted value) * Known hypersensitivity to mannitol, gelatin or strong anaphylactic response in the past.

Design outcomes

Primary

Measure	Time frame	Description
Changes in exhaled breath profile	Immediately post-bronchial challenge	Exhaled volatile organic compounds (VOCs) will be captured on sorbent material and analysed by gas chromatography-mass spectrometry. Post-bronchial challenge samples will be compared with baseline, pre-challenge samples. Differences in exhaled VOC profile will be assessed for significance.

Countries

United Kingdom

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026