Progressive breathlessness in an 18 year old male

A fit 18 year old rugby player presented with a four month history of progressive exertional breathlessness, preceded by an unremarkable flu-like illness. There was no response to inhaled â2-agonist, oral theophylline, or inhaled corticosteroids. At assessment, he was breathless on minimal exertion with wheeze. He had never smoked cigarettes. There was no family history of chest disease. He had worked with fibreglass and hardener for one month and had an inhalation anaesthetic for a tonsillectomy, 18 months previously. On examination, his chest was hyperinflated with decreased expansion, hyper-resonant percussion note, reduced breath sounds, and diVuse polyphonic expiratory rhonchi. Forced expiratory volume in one second was 1.3 litres (30% of predicted), forced vital capacity 4.2 litres (79%), with a ratio of 31%. Residual volume was 3.64 litres (290%) and total lung capacity 8.65 litres (131%). Single