EXhaled Hydrogen Peroxide As a Marker of Lung diseasE (EXHALE) Pilot Study.

Hydrogen Peroxide levels in Exhaled Breath Condensate (EBC) is a direct biomarker of oxidative stress from the airway epithelium. Levels have been shown to be raised in asthma and Chronic Obstructive Pulmonary Disease (COPD) both in stable and exacerbating states.

Previously it has been difficult to measure this volatile compound away from a laboratory based setting. However a new device has been developed to measure Hydrogen peroxide levels in exhaled breath by the patients side.

This Pilot study will test this new device in a clinical setting. It will assess whether the device can monitor levels consistently and reliably and whether it can distinguish disease from healthy individuals.

Inclusion criteria

• Subject has a clinician made diagnosis of asthma with symptoms for ≥ 3 months supported by objective evidence of airflow variability, reversibility or airway hyper-responsiveness
• Subject has a confirmed, clinician made diagnosis of COPD for ≥ 3 months supported by spirometric evidence of fixed airflow limitation (post-bronchodilator ratio of FEV1/FVC <0.7) recorded at any time
• Subject has no known history of lung disease (defined as no current clinical diagnosis of, or be receiving treatment for, a lung disease).
• Subject is willing and able to give informed consent for participation in the study.

Exclusion criteria

• Subject has existing co-morbidities that may prevent them from performing spirometry, FeNO or other study measurements (at the discretion of the clinical investigator).
• Subject has known other lung, chest wall, neuromuscular, or cardiac disease or abnormality (including end-stage disease or cancer) that would confound symptom scores and spirometry.
• Subject has received treatment for an exacerbation of their respiratory disease within the last 2 weeks.
• In the opinion of the clinical investigator, participant could be put at risk of harm by having to perform any of the study procedures.
• Subject is unable to comprehend the study and provide informed consent, e.g. insufficient command of English in the absence of someone to adequately interpret.