Alpha 1-antitrypsin deficiency: the radiological features of pulmonary emphysema in subjects of Pi type Z and Pi type SZ: a survey by the British Thoracic Association.

In a multicentred survey of alpha 1-antitrypsin deficiency, radiological details have been obtained in 165 subjects homozygous for Pi type Z and in 23 subjects heterozygous for type SZ. Eight-five per cent of all type Z subjects had radiological evidence of pulmonary emphysema which was commoner in smokers than in those who had never smoked and which predominantly affected the lower zones of the lungs; 66% of the type Z subjects identified through family studies also had emphysema. Emphysema in subjects of Pi type SZ was limited to those who had smoked; this phenotype may not carry a specific risk of emphysema.