Lung function in 30-year-old alpha-1-antitrypsin-deficient individuals.

BACKGROUND

Alpha-1-antitrypsin (AAT) deficiency increases the risk of emphysema, especially in smokers. In 1972-1974, all 200,000 Swedish new-born infants were screened for AAT deficiency and individuals with severe (PiZZ) and moderate (PiSZ) deficiency have been followed-up regularly. The aim of the present study was to examine their lung function at the age of 30 years, comparing them to a group of age-matched control subjects (PiMM) recruited from the general population, and to compare current smokers with never-smokers.

METHOD

Static and dynamic spirometry, including TLC, FRC, RV, VC, FEV(1,)K(CO) and D(L,CO), was performed for all participants. All values were expressed as percentages of the expected values. FEV(1)/VC was expressed both as percentage of the expected value and in absolute numbers.

RESULTS

Four of 60 PiZZ, none of 19 PiSZ and 9 of 33 PiMM participating individuals were current smokers. All Pi groups had a normal mean FEV(1). The mean (SD) FEV(1)/VC ratio was 75% (7.4) in the PiZZ smokers and 84% (5.5) in the PiZZ never-smokers (p<0.01). The mean (SD) K(CO) was 81 (13) in the PiZZ smokers and 99 (14) in the PiZZ never-smokers (p<0.05).

CONCLUSION

AAT-deficient individuals identified by neonatal screening have normal lung function at the age of 30. The PiZZ smokers had changes in lung function that may be signs of early emphysema.