Lung function in alpha1-antitrypsin deficiency

Hereditary alpha1-antitrypsin (AAT) deficiency predisposes to liver disease and emphysema. The aims of the studies upon which thesis is based were to investigate the natural course of lung function and risk factors for lung disease in AAT-deficient adolescents (PiZZ and PiSZ) and adults (PiZZ), and to study clinical manifestations in AAT-deficient adults. The adolescents were identified at the Swedish neonatal screening study of AAT deficiency (1972-74). Of the adults included in the Swedish national AAT deficiency register started 1991, 42% were identified by respiratory symptoms, 31% by non-respiratory symptoms, and 27% during screening or family studies. The 809 adults in the AAT-deficiency register constituted about 20% of all adult PiZZ individuals in Sweden (prevalence 1/1,600), indicating a high national detection rate of the deficiency state.

As a group, AAT-deficient adolescents had normal lung function, suggesting lung function development to be normal in AAT deficiency, but early signs of lung disease were seen in smokers. In adults, the annual decline of FEV1 (DFEV1) was similar in never-smokers and ex-smokers, but significantly increased in current smokers. After smoking cessation, DFEV1 reverted to the same level as in never-smokers. The results indicate, that the smoking-related pattern of the annual decline in FEV1 is the same in AAT-deficient adults as in the general population, but in AAT deficiency DFEV1 is greater.

In addition to active smoking, passive smoking, domiciliary exposure to kerosene heater emissions, and agricultural work were found to be environmental risk factors for lung disease in AAT deficiency.