Long-term treatment of alpha1-antitrypsin deficiency-related pulmonary emphysema with human alpha1-antitrypsin. Wissenschaftliche Arbeitsgemeinschaft zur Therapie von Lungenerkrankungen (WATL)-alpha1-AT-study group.

Alpha1-antitrypsin (alpha1-AT) deficiency is a genetic disorder characterized by low serum levels of alpha1-AT and a high risk of pulmonary emphysema at a young age. The resulting surplus of proteases, mainly of neutrophil elastase, can be balanced by i.v. augmentation with alpha1-AT. However, it is not clear if affected patients benefit from long-term augmentation therapy and no long-term safety data are available. We examined 443 patients with severe alpha1-AT deficiency and pulmonary emphysema receiving weekly i.v. infusions of 60 mg x kg body weight(-1) alpha1-AT in addition to their regular medication. The progression of the disease was assessed by repeated lung function measurements, particularly the decline in forced expiratory volume in one second (deltaFEV1). Four hundred and forty three patients with alpha1-AT deficiency tolerated augmentation therapy well with few adverse reactions. The deltaFEV1 in 287 patients with available follow-up data was 57.1+/-31.1 mL x yr(-1). Stratified for baseline FEV1, the decline was 35.6+/-21.3 mL in the 108 patients with an initial FEV1 <30% and 64.0+/-26.4 mL in the 164 with FEV1 30-65% of predicted normal (p=0.0008). The remaining 15 patients had an initial FEV1 >65% pred. Long-term treatment with i.v. alpha1-antitrypsin in patients with severe alpha1-antitrypsin deficiency is feasible and safe. The decline in forced expiratory volume in one second is related to the initial forced expiratory volume in one second as in alpha1-antitrypsin deficient patients not receiving augmentation therapy.