Alpha1-antitrypsin (AAT) deficiency – Alpha1 – is an inherited condition in which there are low levels or no levels of AAT in the blood.
Alpha1-antitrypsin (AAT), also known as alpha1-proteinase inhibitor (A1-PI), is an enzyme produced by the liver and released into the bloodstream. One of the primary roles of AAT is to protect the lungs from neutrophil elastase (NE), an enzyme released by white blood cells. Neutrophil elastase can attack healthy lung tissue if not controlled by AAT.
Individuals with AAT deficiency are at high risk for developing emphysema. In addition, approximately 10% of infants and 15% of adults with AAT deficiency experience liver damage.
The American Lung Association estimates that there are about 100,000 people with AAT deficiency in the United States.