1 Guy's Severe Asthma Centre, Guy's & St Thomas' NHS Trust, London, United Kingdom; School of Immunology & Microbial Sciences, King's College London, London, United Kingdom.
2 Department of Radiology, Guy's & St Thomas' NHS Trust, London, United Kingdom.
3 School of Medicine, Kings College London, London, United Kingdom.
4 Guy's Severe Asthma Centre, Guy's & St Thomas' NHS Trust, London, United Kingdom.
5 Guy's Severe Asthma Centre, Guy's & St Thomas' NHS Trust, London, United Kingdom; School of Immunology & Microbial Sciences, King's College London, London, United Kingdom. Electronic address: David.Jackson@gstt.nhs.uk.