Alpha-1-antitrypsin augmentation therapy in deficient individuals enrolled in the Alpha-1 Foundation DNA and Tissue Bank.

INTRODUCTION

Intravenous augmentation therapy with purified intravenous alpha-1 antitrypsin replaces the deficient protein and is the only currently approved treatment for alpha-1 antitrypsin deficiency (AATD) related lung disease. While augmentation therapy has been available for more than 20 years, there are a limited number of studies evaluating the effect of augmentation on lung function.

MATERIAL AND METHODS

We examined the decline in forced expiratory volume in one second (FEV(1)) in patients enrolled in the Alpha-1 Foundation DNA and Tissue Bank in relation to the use or not of alpha-1 antitrypsin augmentation therapy. For the purpose of our analysis we included 164 patients with AATD and PI ZZ genotype.

RESULTS

Mean age of the patients was 60 years, 52% were females, 94% were white and 78% ex-smokers. The mean FEV(1) at baseline was 1.7 L and the mean FEV(1) % of predicted was 51.3%. The mean follow-up time was 41.7 months. A total of 124 (76%) patients received augmentation therapy (augmented group) while 40 patients (24%) did not received it (non-augmented group). When adjusted by age at baseline, sex, smoking status, baseline FEV(1) % of predicted, the mean overall change in FEV(1) was 47.6 mL/year, favoring the augmented group (DeltaFEV(1) 10.6 +/- 21.4 mL/year) in comparison with the non-augmented group (DeltaFEV(1) -36.96 +/- 12.1 mL/year) (P = 0.05). Beneficial DeltaFEV(1) were observed in ex-smokers and the group with initial FEV(1) % of predicted of <50%. No differences were observed in mortality.

CONCLUSIONS

In conclusion, augmentation therapy improves lung function in subjects with AATD when adjusted by age, gender, smoking status and baseline FEV(1) % of predicted. The beneficial effects were noted in ex-smoker subjects with FEV(1) below 50% of predicted.