Decline in pulmonary function in patients with alpha 1-antitrypsin deficiency

Abstract

Sixty-five patients with severe alpha 1-antitrypsin (AAT) deficiency (phenotype PiZ) were followed with spirometry at regular intervals of one year and a median observation period of four years. The annual decline in pulmonary function was adjusted for sex, age and height by division with the predicted normal pulmonary function. The median decline in FEV1 was 1.9% predicted/year. The rate of decline was independent of age and pulmonary function, except for patients with FEV1 below 25% of predicted normal. There was a tendency towards a slower median decline in FEV1 in ex-smokers (1.7% predicted/year) compared to smokers (3.8% predicted/year) and never-smokers (3.7% predicted/year), however, this difference was not significant (p greater than 0.01). At the time of diagnosis smokers and ex-smokers had a lower FEV1 (44 and 38% predicted) than never-smokers (85% predicted) (p less than 0.02), and smokers and ex-smokers were generally younger (median age 44 and 42 years, respectively) than never smokers (median age 55 years) (p greater than 0.1). Our data indicate that smokers as well as nonsmokers with severe AAT deficiency are at risk of developing pulmonary emphysema. The disease seems to appear later in nonsmokers, though once initiated it progresses at the same rate.