Bronchial Challenge Testing in Asthma: The Effect of Mannitol Dry Powder Inhalation on Volatile Organic Compounds in Exhaled Breath
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 46
- 试验地点
- 1
- 主要终点
- Changes in exhaled breath profile
研究概览
简要总结
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.
研究设计
- 研究类型
- Observational
- 观察模型
- Case Crossover
- 时间视角
- Prospective
入排标准
- 年龄范围
- 18 Years 至 —（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •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
排除标准
- •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.
结局指标
主要结局
Changes in exhaled breath profile
时间窗: 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.
次要结局
未报告次要终点