Lung function decline in patients with severe alpha ₁ -antitrypsin deficiency

Severe alpha 1 -antittrypsin deficiency (AATD) is the only known genetic cause of emphysema. There appears to be variability in the clinical course of AATD associated COPD. We present preliminary characterisation of the change in FEV 1 in a cohort of patients with severe AATD. Forced expiratory flow-volume loops measured to ATS/ERS guidelines were retrospectively reviewed from 38 consecutive patients. Values were expressed as mls. There were 38 individuals (18 males), 1 smoker/28 ex-smokers/9 never smokers. Median age (yrs); 64 (16-81) with at least 3 years follow-up. 52.6% had a median decline in FEV 1 of 66mls/year (35-218), greater than the mean rate of decline in COPD (Vestbo J et al, NEJM 2011), including 5 never smokers. 47.4% of the cohort had a decline in FEV 1 < 33mls/yr or improvement in FEV 1; median 23 (-27 -133), 4 never smokers. 50% of these had an improvement in FEV 1 with a median (range) 52 (21 to 133) mls/yr. 71% of never smokers and smokers declined ≥33mls per year. The rate of decline was lower in those with FEV 1 < 50%. Table 1. FEV1 decline dependent on starting value ΔFEV1 (mls) Smoker/Ex-smoker Never smoked FEV1 <50% n=15 -80 (-290 to 320) N/A FEV1 >50% n=14 -150 (-480 to 310) n=9 -130 (-550 to 210) There is considerable variability in change in FEV 1 in patients with severe AATD even in never smokers. A substantial proportion of patients had a faster rate of decline than COPD patients. Interestingly there was also an improvement in lung function in some individuals following attendance at a specialist centre. Further analysis of other lung function parameters and environmental factors e.g. occupation is required which should aid counselling patients and targeting therapies.