Asthma Respiratory Asthma
Conditions
Interventions
This is a single centre study occurring at Southampton Hospital. The study will consist of a screening visit, followed by an imaging visit. Three groups (healthy controls, smokers and asthmatics), wit
Sponsors
Southampton University Hospitals NHS Trust (UK)
Eligibility
Sex/Gender
All
Inclusion criteria
Inclusion criteria: General: 1. Subject must understand the procedures of the study and agree to participation in the study by providing written informed consent 2. Subject considered fit enough to undergo lung function testing including provocation tests 3. Either gender 4. Age 18 - 55 years at screening Group specific: 1. Healthy controls: 1.1. Lifelong non-smoker 1.2. No history suggestive of airways disease 1.3. Normal spirometry, normal exhaled nitric oxide (NO), provocative concentration causing a 20% fall in forced expiratory volume in one second (FEV1) (PC20) (metacholine) greater than 8 mg/ml (non-cumulative) 1.4. No signs of concurrent respiratory infection at time of scanning or within previous 8 weeks 1.5. No significant cardiopulmonary/hepatic or renal co-morbidity 2. Smokers: 2.1. Daily smokers of tobacco cigarettes 2.2. Normal spirometry, normal exhaled NO, PC20 (metacholine) greater than 8 mg/ml (non-cumulative) 2.3. No signs of concurrent respiratory infection at time of scanning or within previous 8 weeks 3. Asthmatics - controlled: 3.1. Asthma defined as per BTS guidelines, on treatment with inhaled corticosteroids +/- long-acting beta-agonists 3.2. Lifelong non-smokers (never smoked) 3.3. Clinically stable with FEV1 greater than 70% post-bronchodilator use, with use of rescue bronchodilators less than 3 x week 3.4. No signs of concurrent respiratory infection at time of scanning or within previous 8 weeks 4. Asthmatics - uncontrolled: 4.1. Asthma defined as per BTS guidelines, on treatment with inhaled corticosteroids +/- long-acting beta-agonists 4.2. Lifelong non-smokers (never smoked) 4.3. Use of rescue bronchodilator greater than 3 times a week 4.4. No signs of concurrent respiratory infection at time of scanning or within previous 8 weeks
Exclusion criteria
Exclusion criteria: 1. Pregnancy (where pregnancy is defined as the state of a female after conception and until the termination of gestation, confirmed by a positive human chorionic gonadotrophin [hCG] laboratory test greater than 5 mIU/ml), an intention to become pregnant or breast-feeding (lactating) 2. Subjects with active lung disease other than asthma 3. Significant medical co-morbidity which in the view of the investigator could impact on the interpretation of results or participation in the trial 4. Active cancer or a history of cancer or radiotherapy 5. Current/previous users of recreational inhaled illicit drugs, e.g. cannabis, crack cocaine, etc. 6. Inability to lie flat for scan for 2 hours 7. Those who have participated in a clinical trial involving an investigational or marketed drug within 12 weeks of screening, or participated in any study involving radiation within 12 months of screening 8. Those in any situation which, in the opinion of the investigator, may interfere with optimal participation in the study 9. Those unable to optimally perform the breathing manoeuvres required for lung function testing, or deposition of the radio-labelled aerosol 10. Signs of concurrent respiratory tract infection on examination at the time of scanning or within previous 8 weeks (can be rescreened after 8 weeks if otherwise eligible)
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Measurement of clearance of Indium 111-labelled DTPA from the lungs of healthy controls, smokers and asthmatics, measured at the time of the imaging visits, between 14 and 28 days from their screening visit. | — |
Secondary
| Measure | Time frame |
|---|---|
| 1. Measurement of mucociliary clearance using technetium labelled albumin as a microcolloid, 99mTc-Nanocoll, in normal subjects, asthmatics and smokers and comparison for statistically significant difference 2. Lung function and volume measurements (FEV1, forced vital capacity [FVC], forced mid-expiratory flow rate [FEF25-75], reversibility with salbutamol, functional residual capacity [FRC] and total lung capacity [TLC]) together with provocation testing (PC20 metacholine) and exhaled nitric oxide (eNO) will be recorded and correlated with degree of permeability if possible 3. History of atopy will be recorded and correlated with permeability 4. Lung sounds will be recorded for analysis and correlation with airflow obstruction Measured at the time of the imaging visits, between 14 and 28 days from their screening visit. | — |
Countries
United Kingdom
Outcome results
None listed