S Khan1, N Clerk2, K Galloway2, R Mustafa2, G Antunes2. 1. From the Department of Respiratory Medicine, James Cook University Hospital, Marton Road, Middlesbrough TS4 3BW, UK sehrish.khan@nhs.net. 2. From the Department of Respiratory Medicine, James Cook University Hospital, Marton Road, Middlesbrough TS4 3BW, UK.