Decline in FEV1 in patients with PiZ alpha-1-antitrypsin deficiency: the Australian experience.

Abstract

Alpha-1-antitrypsin (alpha1antitrypsin) deficiency is a rare hereditary disorder which characteristically presents with emphysema at an early age. The aim of the present study was to determine whether the rate of decline of lung function in alpha1antitrypsin-deficient subjects in Australia was similar to that found elsewhere. Patients registered with the Australian Alpha-1-Antitrypsin Replacement Program were studied. All patients (n = 50) had a serum alpha1antitrypsin concentration of < 0.3 g/L and had had spirometry measured over at least 2 years. They were compared with a group of normal volunteers (hospital staff, n = 107) with normal alpha1antitrypsin levels and phenotypes and with no clinical history of lung disease. All had spirometry measured for periods ranging from 2 to 6 years. The rate of decline of forced expiratory volume in 1 s (FEV1) for each subject was calculated by least squares linear regression using FEV1 against the time from entry into the study. The group mean (+/- SD) rate of decline in FEV1 was significantly greater (P < 0.01) in the alpha1antitrypsin-deficient patients (88 +/- 71 mL/year) than for the normal controls (-15 +/- 48 mL/year). There was no difference in decline in FEV1 when the data was analysed for gender and for index versus non-index cases. The results confirm previous reports of an accelerated rate of decline of FEV1 in patients with alpha1antitrypsin deficiency. Our results indicate that the rate of decline of lung function in alpha1antitrypsin deficient subjects in Australia is similar to that found in reported series from elsewhere.