Rate of Progression of Lung Function Impairment in Alpha-1-Antitrypsin Deficiency

¹ Lung Investigation Unit, University Hospital Birmingham and University of Birmingham

^* To whom correspondence should be addressed. E-mail: p.a.dawkins{at}bham.ac.uk.

	Abstract

The aim was to identify alpha-1-antitrypsin (A1AT) deficient patients who have rapidly progressive disease.

101 PiZ patients had annual lung function measurements over a 3-year period and the results were related to factors that may influence decline.

Mean annual decline of forced expiratory volume in 1 second (FEV₁) was 49.9 ml. The greatest FEV₁ decline was in the moderate severity group (FEV₁ 50–80 %) with mean annual decline of 90.1 ml, compared with 8.1 ml in the very severe group (FEV₁ <30%). However, annual decline in KCO was greatest in the severe and very severe groups. When the whole group was divided into tertiles for FEV₁ decline, the fast tertile compared with the slow tertile had more patients with bronchodilator reversibility (BDR) (mean 73% versus 41%, p=0.010), more males (mean 79% versus 56%, p=0.048) and lower body mass index (BMI) (mean 24.0 versus 26.1, p=0.042). Logistic regression analyses confirmed FEV₁ decline was independently associated with BMI, BDR, exacerbation rate and high physical component SF36 scores.

In PiZ A1ATD patients, FEV₁ decline was greatest with moderate disease, unlike KCO decline that was greatest in severe disease. The FEV₁ decline showed associations with BDR, BMI, gender and exacerbation rates.