Lung function in relation to emphysema development in alpha-1 antitrypsin deficiency

Rationale: Alpha-1 Antitrypsin Deficiency (AATD) is a rare genetic disease that can lead to the emphysema. Evidence suggests that small airways (SA) disease precedes emphysema. We compared traditional lung function and SA tests to CT evidence of emphysema in AATD subjects with mild or no COPD. Methods: 70 non-smokers with severe (PiZZ) AATD underwent lung function testing and high resolution CT (HRCT) scan. They were categorised based on HRCT data (Gevenois, P.A., et al. ERJ 1995; 5: 843–848); No emphysema (PD15 > -910HU, n=16), microscopic emphysema (PD15 -950 to -910HU, n=48) and macroscopic emphysema (PD15 Results: There was progressively worsening lung function from no emphysema to microscopic and macroscopic emphysema observed for all parameters except R5-R20. Comparisons of FEV1/FVC, MMEF, AEx/FVC, LCI and Kco reached statistical significance (Table 1). Conclusions: There is a natural progression in traditional and SA lung function tests with the development of emphysema in AATD. The data suggest that monitoring lung function can detect deterioration before COPD and macroscopic emphysema becomes established. THIS RESEARCH IS FUNDED BY THE ALPHA-1 FOUNDATION