The role of ATP in the mechanism of refractory chronic cough Respiratory
Conditions
Interventions
Subjects with refractory chronic cough and healthy volunteers will be recruited from a single UK centre and undergo inhalational challenges (lasting approximately 40 minutes per challenge) at 2 - 7 da
Sponsors
University of Manchester
Eligibility
Sex/Gender
All
Age
18 Years to 80 Years
Inclusion criteria
Inclusion criteria: 1. Males and females 18 - 80 years, inclusive 2. Non-smokers; ex-smokers 6 months abstinence 3. Healthy volunteers: 3.1. No clinically relevant abnormalities based on the medical history, physical examination, vital signs 3.2. No history of current or significant past respiratory disease, specifically a diagnosis of asthma 3.3. Spirometry within normal limits 4. Chronic cough patients: 4.1. Have a refractory chronic cough as defined by BTS/ERS guidelines 4.2. No evidence of asthma during clinical evaluation of chronic cough, e.g. elevated FeNO, bronchodilator reversibility, abnormal methacholine responsiveness
Exclusion criteria
Exclusion criteria: 1. Any condition that may increase airway/circulating levels of ATP/adenosine, e.g. chronic cardiac failure, chronic hypoxia, and vigorous exercise 2. Pregnancy or breastfeeding 3. Upper or lower respiratory tract infection or significant change in pulmonary status within 4 weeks of enrolment. 4. Any therapy that may modulate cough (e.g. ACE inhibitors, opioids, gabapentin) 5. Patients with asthma
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Current primary outcome measures as of 03/07/2025: 1. Cough responses in all subjects measured by Emax and ED50 at each challenge visit 2. Blood ATP levels following inhalational challenges at baseline, 15 minutes, and 30 minutes post-challenge with each challenge agent measured by blood test Previous primary outcome measures: 1. Cough responses in all subjects measured by Emax and ED50 at each challenge visit 2. Blood ATP levels following inhalational challenges at baseline, 15 minutes, 30 minutes, 45 minutes and 60 minutes with each challenge agent measured by blood test | — |
Secondary
| Measure | Time frame |
|---|---|
| Current secondary outcome measures as of 03/07/2025: 1. Blood ATP metabolite levels following inhalational challenges at baseline, 15 minutes, and 30 minutes post-challenge measured by blood test 2. Urge to cough sensations measured by visual analogue scale before and after each inhalational challenge Previous secondary outcome measures: 1. Blood ATP metabolite levels following inhalational challenges at baseline, 15 minutes, 30 minutes, 45 minutes and 60 minutes measured by blood test 2. Urge to cough sensations measured by visual analogue scale before and after each inhalational challenge | — |
Countries
England, United Kingdom
Contacts
Public ContactJoanne Mitchell
Outcome results
None listed