What is alpha-1 antitrypsin deficiency?
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 joints. 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.
Alpha-1 antitrypsin is a protein that is made in the liver. Alpha 1-antitrypsin is a blood protein that diffuses into tissue spaces to protect tissues from being harmed by enzymes released from cells when they are injured and inflamed. Alpha-1-Antitrypsin is ordinarily released by specialized, granular white blood cells (neutrophils) in response to infection or inflammation. The liver releases this protein into the bloodstream. Alpha-1 antitrypsin protects the lungs so they can work normally. Without enough alpha-1 antitrypsin, the lungs can be damaged, and this damage may make breathing difficult. In addition, liver damage (hepatitis, cirrhosis) can occur in both children and adults. Alpha-1 antitrypsin deficiency is an inherited (passed down from parents) disorder that causes low levels of, or no alpha-1 antitrypsin in the blood.
The disease most often appears in the newborn period with jaundice, swelling of the abdomen, and poor feeding. It may also appear in late childhood or adulthood and be detected because of fatigue, poor appetite, swelling of the abdomen and legs or abnormal liver tests. Although the deficiency is frequently associated with lung disease in adults, the disease also affects liver cells. Liver involvement is more common in children than in adults. Occurring in approximately 1 of each 1600 live births, A1AT deficiency is the most common genetic cause of liver disease in children. Liver disease occurs in approximately 10% of infants born with a severe form of the deficiency. Some adults with a severe or intermediate form of A1AT deficiency also develop cirrhosis or liver cancer.
Tobacco smoking worsens alpha-1 antitrypsin lung damage. It irritates and damages the lungs, prompting the body to send more white blood cells to protect them. The more white blood cells there are, the more neutrophil elastase is made, causing even more lung damage. The smoke itself also alters alpha-1 antitrypsin so that it cannot do as good a job protecting the lungs from harm. Smokers with alpha-1 antitrypsin deficiency have a faster rate of lung damage.