Identifying the Causes and Risk Factors of Pulmonary Exacerbations in Cystic Fibrosis

Participants will be recruited by staff within the care of UK CF centres. Initial discussions will occur either during routine outpatient reviews, telephone consultations or during admissions. Consent will take place prior to any other procedures. There will be four separate cohorts of participant 1. Group A participants will be 200 adults with CF (16 years or older) attending a UK adult CF centre taking part in the study 2. Group B participants will be 100 additional adults with CF attending one of the five core CF adult centres: Manchester, Leeds, Newcastle, Cardiff, Liverpool. 3. There will be a pilot study to test the practicalities of running the same protocol in a paediatric population. This will consist of up to 25 children with CF (5-16 years) attending a paediatric clinic in one of the five core centres. 4. In addition, the investigators will recruit up to 40 healthy volunteers to provide samples on a single occasion as controls. Group A participants will have a single in-person visit, at the start of the study. Clinical data, including lung function (spirometry), venous blood draw, sweat chloride, saliva sample and finger-prick dried blood spot sample, sputum, nasal liquid sample and urine sample and demographic data will be collected. The study will run for 12 months. Home sampling kit, consisting of 13 home sampling boxes and 3 additional exacerbation boxes, will be provided for participants to collect in-home sampling for the first 6 months fortnightly. The 3 additional exacerbation boxes will be provided for posting additional set of samples when unwell. There will be questionnaires to complete to remotely monitor the adherence to the protocol. Study app ("Watson") will be set up to provide reminders and aid study adherence and timely return of samples. Group B will only be offered at 5 specialist CF centres (Manchester, Cardiff, Newcastle, Leeds, Liverpool). This follows the same format as Group A but includes additional face to face visits at 1 and 6 months, and the invitation to return for additional samples if unwell. In Group B, those attending the Manchester clinic will have the option of taking part in a 12 month home environmental and pollution monitoring and sleep monitoring (both optional arms). The investigators will include an additional feasibility cohort of up to 25 paediatric patients (aged 5-15 years). This will open in up to 4 centres who are already running the adult study. The basic study protocol will be the same as for Group A, with a single patient visit at the start of the study and the remainder of the assessments from home monitoring. Parental consent, participant consent and assent will be obtained. In order to ensure that the investigators have reference values for some of the established and experimental biomarkers, the investigators will also collect samples from 40 healthy volunteers on a single occasion. Visits will take place at CRFs and are planned for the Manchester site only. Clinical samples, including sputum, venous blood draw, nose and throat swabs, FeNo, VOCs and nasal liquid, and demographic information will be collected.