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

Abstract

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 (ΔFEV ₁ 10.6 ± 21.4 mL/year) in comparison with the non-augmented group (ΔFEV ₁ −36.96 ± 12.1 mL/year) ( P = 0.05). Beneficial ΔFEV 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.