Alpha1 antitrypsin deficiency is a genetic disorder caused by a lack of alpha1 antitrypsin, a protein produced mostly in the liver. The primary role of alpha1 antitrypsin is to protect the lungs from neutrophil elastase, an enzyme that normally digests damaged or aging cells and bacteria to keep the lungs healthy. If it is not regulated, neutrophil elastase can attack healty tissue and cause lung damage. People with Alpha-1 do not produce enough alpha1 antitrypsin to keep neutrophil elastase from causing damage that may lead to lung disease and the signs and symptoms of emphysema.

In Alpha-1 patients with evidence of emphysema, doctors may prescribe Alpha-1 augmentation therapy in combination with bronchodilators and antibiotics for respiratory infections. Augmentation therapy raises the level of alpha1 antitrypsin in the blood and inhibits neutrophil elastase.