Alpha-1 Antitrypsin (AAT) Deficiency Testing
Overview
Alpha-1 antitrypsin (AAT) is a protein normally found in the lungs and the bloodstream. It helps protect the lungs from diseases such as emphysema and chronic obstructive pulmonary disease (COPD). Some people do not make enough of this protein or they make an abnormal type of AAT, either of which can cause AAT deficiency. These people are more likely to have lung diseases and will get them at a younger-than-normal age (30 to 40 years old). Some types of abnormal AAT can also damage the liver. AAT deficiency is a rare disorder and is the only known genetic (inherited) factor that increases your chances for developing emphysema.
Alpha-1 antitrypsin deficiency is caused by a change, or mutation, in the gene, Opens dialog that tells the body how to make alpha-1 antitrypsin. There are many kinds of possible changes in this gene, but only a few cause problems. To have this condition, you have to get the changed gene from both parents.
If you receive only one changed gene, you do not have the disease but are a carrier, Opens dialog. The good copy of the gene you received from your other parent is enough to tell your body how to properly make alpha-1 antitrypsin. Some people who carry the changed gene may have very mild symptoms of the deficiency.
Treatment for alpha-1 antitrypsin deficiency involves avoiding substances—especially cigarette smoke—that could harm your lungs. Also try to avoid dust and workplace chemicals. You also may want to avoid alcohol because of the risk of liver damage. Exercise can improve your stamina and overall health. You may also need medicines and other treatments to help you breathe easier and stay as healthy and strong as you can.
The only treatment available for the lack of the protein is plasma containing alpha-1 antitrypsin. This is usually given only to people who have very low levels of AAT in their blood. It is not clear that this treatment is any better than avoiding smoke and other lung-damaging chemicals. The plasma is made from the blood of many donors and is treated to reduce the chance of spreading an infectious disease. You receive the plasma through an I.V., usually every 3 to 4 weeks for life.
