What Is Alpha-1 Antitrypsin Deficiency?

Alpha-1 antitrypsin deficiency, or AAT deficiency, is a condition that raises your risk for certain types of lung disease, especially if you smoke. AAT deficiency is an inherited condition. "Inherited" means it's passed in the genes from parents to children.

 

Some people who have severe AAT deficiency develop emphysema - often when they're only in their forties or fifties. Emphysema is a serious lung disease in which damage to the airways makes it hard to breathe.

 

A small number of people who have AAT deficiency have cirrhosis and other serious liver diseases.

 

Cirrhosis is a disease in which the liver becomes scarred. This prevents the liver from working right. In people who have AAT deficiency, cirrhosis and other liver diseases usually occur in infancy and early childhood.

 

A very small number of people who have AAT deficiency have a rare type of skin disease called necrotizing panniculitis. This skin disease can cause painful lumps under or on the surface of the skin.

 

This article will focus on AAT deficiency as it relates to lung disease.

 

Overview

Alpha-1 antitrypsin, also called AAT, is a protein made in the liver. Normally, the protein goes into the bloodstream and helps protect the body's organs from the harmful effects of other proteins. One of the main organs it protects is the lungs.

 

AAT deficiency occurs if the AAT proteins made in the liver aren't the right shape. They get stuck inside liver cells and can't get into the bloodstream. Because not enough AAT protein travels to the lungs to protect them, the risk of lung disease increases. Also, because too many AAT proteins are stuck in the liver, liver disease can develop.

 

AAT deficiency is considered severe when blood levels of the AAT protein fall below the lowest amount needed to protect the lungs.

 

AAT deficiency is an inherited condition caused by altered genes. It's not known how many people have it. Many people who have the condition may not know they have it. Estimates of how many people have AAT deficiency range from about 1 in every 1,600 people to about 1 in every 5,000 people.

 

Outlook

You may not have any serious complications if you have AAT deficiency, and you may live a normal lifespan. Many people who have AAT deficiency but don’t smoke will not develop any serious related lung diseases.

 

Among people with AAT deficiency who do have a related lung or liver disease, about 3 percent die each year. Smoking is the leading risk factor for life-threatening lung disease if you have AAT deficiency. If you have severe AAT deficiency, smoking can shorten your life by as much as 20 years.

 

AAT deficiency has no cure, but treatments are available. In most cases, treatment is based on the type of disease you develop.

 

 

"Strength does not come from physical capacity. It comes from an indomitable will."

 

What Causes Alpha-1 Antitrypsin Deficiency?

Altered alpha-1 antitrypsin (AAT) genes cause AAT deficiency.

 

AAT genes are inherited - that is, passed from parents to children. Children who have AAT deficiency inherit two altered AAT genes, one from each parent. These genes tell cells in the body how to make AAT proteins.

 

In AAT deficiency, the AAT proteins made in the liver aren't the right shape. They get stuck in the liver cells where they’re made. The proteins can't get to the organs in the body that they protect, such as the lungs. Without the AAT proteins protecting the organs, diseases can develop.

 

Many gene alterations can cause AAT deficiency. The most common altered AAT gene that can cause AAT deficiency is called PiZ.

 

You’ll have AAT deficiency if you inherit two PiZ genes. If you inherit a PiZ gene from one parent and a normal AAT gene from the other parent, you won’t have AAT deficiency. However, you may pass the PiZ gene to your children.

 

Even if you inherit two altered AAT genes, you may not have any related complications. You may never even realize that you have this inherited condition.

 

Key Points

• Alpha-1 antitrypsin deficiency is a condition that raises your risk for certain types of lung disease, especially if you smoke. A small number of people who have AAT deficiency develop liver disease, and a very small number develop a rare skin disease.

 

• Alpha-1 antitrypsin, also called AAT, is a protein made in the liver. Normally, the protein goes into the bloodstream and helps protect the body's organs from the harmful effects of other proteins. One of the main organs it protects is the lungs.

 

• In AAT deficiency, the AAT proteins made in the liver don’t have the right shape. They get stuck inside liver cells and can't get into the bloodstream. This means that the organs don't get enough protection, and the liver has too many AAT proteins in it.

 

• AAT deficiency is an inherited condition. "Inherited" means it's passed in the genes from parents to children. If you have bloodline relatives who have AAT deficiency, you're more likely to have the condition.

 

• You may not have any serious complications if you have AAT deficiency, and you may live a normal lifespan. Many people who have AAT deficiency and don’t smoke will not develop any serious related lung diseases.

 

• You may have AAT deficiency if you have signs and symptoms of a serious lung condition, especially emphysema, without any obvious cause. Another sign of AAT deficiency is if you develop emphysema when you’re 45 years old or younger.

 

• Your doctor will diagnose AAT deficiency based on your medical and family histories, any risk factors you have, and the results from diagnostic tests.

 

• AAT deficiency has no cure. However, the lung diseases related to this inherited condition have many treatments. These include lifestyle changes, medicines, vaccines, pulmonary rehabilitation, and surgery.

 

• You can't prevent AAT deficiency because the condition is inherited. If you inherit two altered AAT genes, you’ll have AAT deficiency. However, you can take steps to prevent or delay the lung diseases related to this condition. Quitting smoking and avoiding secondhand smoke, dust, fumes, and other toxic substances are important steps.

 

• Researchers continue to look for new treatments for AAT deficiency.