Alpha-1 Antitrypsin Deficiency (A1AD) is a hereditary disorder characterized by low levels of a protein called alpha-1 antitrypsin (A1AT) which is found in the blood. This deficiency may predispose an individual to several illnesses but most commonly appears as emphysema, less commonly as liver disease, or more rarely, as a skin condition called panniculitis. A deficiency of A1AT allows substances that break down protein (proteolytic enzymes) to attack various tissues of the body. This results in destructive changes in the lungs (emphysema) and may also affect the liver and skin. Alpha-1 Antitrypsin is ordinarily released by specialized, granular white blood cells (neutrophils) in response to infection or inflammation. A deficiency of Alpha-1 Antitrypsin results in unbalanced (relatively unopposed) rapid breakdown of proteins (protease activity), especially in the supporting elastic structures of the lungs. This destruction over many years leads to emphysema and is accelerated by smoking and some occupational exposures.