Alpha-1 antitrypsin deficiency is a lack of a primary lung antiprotease, alpha-1 antitrypsin, which leads to increased protease-mediated tissue destruction and emphysema in adults.
Alpha-1 antitrypsin (AAT) deficiency affects the production of alpha-1 antitrypsin by the liver.
There are several different genetic mutations, but the most common is called the PiZ allele. This mutation causes the liver to produce an abnormal form of the alpha-1 antitrypsin protein, which is then deposited in the liver cells instead of being released into the bloodstream to protect the lungs.
The accumulation of the abnormal protein in the liver cells can lead to liver damage and increase the risk of developing liver disease, such as cirrhosis and liver cancer. Additionally, the lack of functional alpha-1 antitrypsin in the bloodstream can allow enzymes called proteases to attack and damage the lung tissue, leading to respiratory problems such as emphysema and chronic obstructive pulmonary disease (COPD).