Asthma Bronchial Challenge: The ABC Study
Research type
Research Study
Full title
Bronchial Challenge Testing in Asthma: The Effect of Mannitol Dry Powder Inhalation on Volatile Organic Compounds in Exhaled Breath
IRAS ID
229225
Contact name
Adam M Peel
Contact email
Sponsor organisation
University of East Anglia
Duration of Study in the UK
0 years, 10 months, 30 days
Research summary
Asthma is a disease characterised by airways inflammation and bronchial hyperresponsiveness (BHR) which leads to the constriction of airways. Research into exhaled breath biomarkers for asthma can be challenging for a number of reasons; samples obtained from participants with well-controlled asthma may have little disease activity and therefore limited value; while obtaining breath samples from patients during an acute asthma attack is difficult.
Bronchial challenge testing attempts to identify BHR through the inhalation of a stimulus at doses which cause no significant reaction in healthy subjects but provokes airway constriction in those with BHR. Indirect bronchial challenge testing using mannitol dry powder works by provoking inflammatory cells, causing the release of inflammatory mediators. These mediators act upon airway smooth muscle to cause airway constriction.
Bronchial challenge tests are recommended by asthma guidelines as a means of confirming diagnosis and they are safe to use in patients with mild-to-moderate asthma. We plan to obtain breath samples after a positive mannitol challenge thereby ensuring our samples are from airways with inflammatory activity. Unlike samples obtained during an asthma attack, samples obtained after a mannitol challenge can be collected in an organised, controlled and comfortable manner.
We plan 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. Breath samples will be collected before and after a mannitol bronchial challenge test and changes in VOC profiles observed.
In addition to VOC profile changes caused by inflammatory activity, we anticipate that test procedures (such as repeated spirometry) will also cause changes. In order to take these into account, this will be a two-visit study in which participants will be randomised to receive a sham challenge during one visit and a genuine mannitol challenge in another.
REC name
East of England - Cambridge South Research Ethics Committee
REC reference
17/EE/0430
Date of REC Opinion
12 Dec 2017
REC opinion
Further Information Favourable Opinion