Table 1.

Published studies of AAT augmentation therapy

STUDY	STUDY DESIGN	TREATMENT PROTOCOL	OUTCOME	LEVEL OF EVIDENCE
Seersholm et al,1 1997	Observational, nonrandomized study; comparison of rate of change in FEV1 in treated German patients vs untreated Danish patients	Weekly AAT therapy, 60 mg/kg	Significant difference in rate of decline in FEV1 between the groups (P = .02): treated German patients 53 mL/y vs untreated Danish patients 75 mL/y; difference of 22 mL/y	II
AATD Registry Study Group,2 1998	Observational, nonrandomized study	AAT therapy, 60 mg/kg (51% weekly, 25% biweekly, 22% monthly)	Significantly lower rate of FEV1 decline (mean difference 27 mL/y) in treated patients with FEV1 at 35% to 49% of predicted value (P = .03); decreased mortality in treated group (P = .02)	II
Dirksen et al,3 1999	Randomized controlled trial	Every 4 wk, AAT therapy (250 mg/kg) or placebo (albumin, 625 mg/kg)	Nonsignificant difference in loss of lung tissue between groups: placebo group 2.6 g/L/y vs treated group 1.5 g/L/y (P = .07)	I
Lieberman,4 2000	Observational, Web-based survey	AAT therapy, 60 mg/kg/wk (54% weekly, 35% biweekly, 7% monthly)	Number of lung infections decreased from 3–5/y pretreatment to 0–1/y posttreatment (P < .001)	II
Wencker et al,5 2001	Multicentre, retrospective cohort study; comparison of rate of FEV1 decline before and after treatment	Weekly AAT therapy, 60 mg/kg	Significant difference in rate of FEV1 decline: 49.2 mL/y pretreatment vs 34.2 mL/y posttreatment (P = .019)	II
Dirksen et al,6 2009	Randomized, multicenter, double-blind, placebo-controlled, parallel-group	Weekly, AAT therapy (60 mg/kg) or placebo (2% albumin)	CT is a more sensitive outcome measure of emphysema-modifying therapy than physiology and health status; a trend toward treatment benefit from AAT augmentation therapy was demonstrated	I

AAT—α₁-antitrypsin, AATD—α₁-antitrypsin deficiency, CT—computed tomography, FEV₁—forced expiratory volume of air in 1 second.