Exhaled Hydrogen Sulphide as a Biomarker of Airways Disease in Asthma
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|ClinicalTrials.gov Identifier: NCT02703467|
Recruitment Status : Completed
First Posted : March 9, 2016
Results First Posted : October 21, 2019
Last Update Posted : October 21, 2019
The purpose of this study will be to determine whether there is any role for measuring Hydrogen Sulphide (H2S) in the exhaled breath in terms of management of the patient with asthma.
The investigators will recruit patients with a range of severity of asthma and health volunteers. Levels of Hydrogen Sulphide will be measured in exhaled breath and blood. Also exhaled Nitric Oxide, Spirometry and asthma symptom scores will be measured at each study visit. Participants will attend either 2 or 4 separate visits.
The investigators will determine whether there is a relationship between exhaled Hydrogen Sulphide and asthma severity.
|Condition or disease|
- Perform a cross-sectional study in non-asthmatic subjects and asthmatic subjects of varying severities of the levels of Hydrogen Sulphide in exhaled breath in relation to the severity and control of asthma
- Compare the levels of exhaled Hydrogen Sulphide with exhaled Nitric Oxide.
We will recruit 30 health volunteers and 90 patients with a range of severity of asthma.
Particpants will attend for either 2 or 4 visits. At these visits the following measurements will be taken:
- Exhaled Hydrogen Sulphide
- Serum Hydrogen Sulphide
2. Exhaled Nitric Oxide 3. Spirometry 4. Asthma Symptom Score (ACQ)
The investigators will use a Hydrogen Sulphide UV fluorescent machine Model T101 (0-50 ppb to 0-20 ppm) (Cal-Bay Control Inc, USA) to measure directly on line exhaled breath Hydrogen Sulphide. This method has been used previously in normal people, but we will first determine whether there is an exhaled flow-dependence on the measurement of H2S levels. The investigators will use a hand-held Nitric Oxide machine (NO Breath) to measure Nitric Oxide in exhaled breath.
Subjects must have asthma according to one or more of the following criteria documented in the last 12 months:
- Improvement in FEV1 (forced expiratory volume at one second) ≥ 12% and 200ml predicted after inhalation of 400 mcg salbutamol
- Airway hyper-responsiveness (PC20 <8mg/ml)
- Diurnal variation in PEF (peak expiratory flow): amplitude % mean of twice daily PEF > 8%
- Decrease in pre-bronchodilator FEV1 >12% and >200mls within 4 weeks after tapering treatment with one or more of the following drugs: inhaled corticosteroids, oral corticosteroids, long-acting beta-agonists, long-acting beta-agonists and short-acting beta-agonists.
PLUS A history of wheeze occurring spontaneously or on exertion
|Study Type :||Observational|
|Actual Enrollment :||70 participants|
|Official Title:||Exhaled Hydrogen Sulphide as a Biomarker of Airways Disease in Asthma|
|Actual Study Start Date :||August 1, 2015|
|Actual Primary Completion Date :||June 30, 2016|
|Actual Study Completion Date :||June 30, 2016|
Healthy subjects will have no significant medical history and no previous history of asthma or other serious illnesses. They should be non-smokers. The investigators willl measure spirometry and ensure that the values lie within the normal predicted range.
Patients diagnosed as having asthma will be recruited from Royal Brompton Hospital Asthma Clinics. These patients will have a range of severity of asthma ranging from mild-moderate to severe asthma patients. The diagnosis of asthma is ascertained as described in the inclusion criteria.
- Hydrogen Sulphide in Exhaled Breath [ Time Frame: At baseline visit ]Level of hydrogen sulphide in exhaled breath measured as parts per billion
- FEV1 [ Time Frame: At baseline visit ]Forced expiratory volume in one second as percent of predicted value (%)
- FVC (Forced Vital Capacity) [ Time Frame: At 4 visits which occur during the study duration, up to 1 year ]Forced vital capacity as per cent of predicted
- Exhaled Nitric Oxide [ Time Frame: At 4 visits which occur during the study duration, up to 1 year ]Levels of nitric oxide in exhaled breath in parts per billion
- Blood Hydrogen Sulpide Level [ Time Frame: At 4 visits which occur during the study duration, up to 1 year ]Hydrogen Sulpide level measurements from blood
Biospecimen Retention: Samples Without DNA
To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT02703467
|Royal Brompton Hospital|
|London, United Kingdom, SW3 6HP|
|Principal Investigator:||Kian F Chung, MBBS MD FRCP||Imperial College London|