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Alpha-1 Antitrypsin Deficiency FAQ's

What Is Alpha-1 Antitrypsin Deficiency?

Alpha-1 antitrypsin (an-tee-TRIP-sin) 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 (em-fi-SE-ma)—often when they're only in their 40s or 50s. 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 (sir-RO-sis) and other serious liver diseases.

Cirrhosis is a disease in which the liver becomes scarred. This prevents the liver from working properly. 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 (pa-NIK-yu-LI-tis). This skin disease can cause painful lumps under or on the surface of the skin.

The following information will focus on AAT deficiency as it relates to lung 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.

AAT deficiency occurs if the liver doesn’t produce enough AAT proteins or the AAT proteins that are 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.


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 three 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.

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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.

AAT deficiency occurs if the liver doesn’t produce enough AAT proteins or the AAT proteins that are 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. Another common altered gene is PiS. A normal AAT gene is known as PiM.

If you inherit a PiZ gene from one parent and a normal AAT gene from the other parent, you are considered a “carrier” of the alpha-1 gene. Carriers may or may not have an increased risk of developing emphysema as a result. As a genetic disease, alpha-1 may be passed on 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.

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Who Is at Risk for Alpha-1 Antitrypsin Deficiency?

In the United States, Caucasians of western and northern European descent are more likely than other ethnic groups to have alpha-1 antitrypsin (AAT) deficiency, but the disease can affect people of any ethnicity.

Many other gene alterations can cause AAT deficiency, but PiZ is the most common.

AAT deficiency is an inherited condition. If you have bloodline relatives with known AAT deficiency, you're more likely than others to have the condition. Even so, it doesn't mean that you’ll develop one of the diseases related to the condition.

Some risk factors make it more likely that you’ll develop lung disease if you have AAT deficiency. Smoking is the leading risk factor for serious lung disease if you have AAT deficiency. Your risk also may go up if you're exposed to dust, fumes or other toxic substances.

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What Are the Signs and Symptoms of Alpha-1 Antitrypsin Deficiency?

You may have alpha-1 antitrypsin (AAT) deficiency if you have signs and symptoms of a serious lung condition, especially emphysema, without any obvious cause.

Developing emphysema before 45 is another sign of AAT deficiency. Signs and symptoms of emphysema include shortness of breath, wheezing, decreased capacity for physical activity and coughing.

At first, many people who have AAT deficiency are diagnosed with asthma. This is because wheezing also is a symptom of asthma.

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How Is Alpha-1 Antitrypsin Deficiency Diagnosed?

Alpha-1 antitrypsin (AAT) deficiency usually is diagnosed after you develop a lung or liver disease that's related to the condition.

Because of this, a number of doctors may be involved in the diagnosis of AAT deficiency. These include primary care doctors, pulmonologists (lung specialists) and hepatologists (liver specialists).

To check whether the disease you have may be related to AAT deficiency, your doctor will:

Diagnostic Tests

Your doctor may recommend tests to confirm a diagnosis of AAT deficiency. He or she also may recommend tests to check for lung- or liver-related conditions.

A genetic test is the most certain way to check for AAT deficiency. This test will show whether you have altered AAT genes.

A blood test also may be used. This test checks the levels of AAT protein in your blood. If the levels are a lot lower than normal, it's likely that you have AAT deficiency.

Lung-related Tests

If you have a lung disease related to AAT deficiency, your doctor may recommend lung function tests and high-resolution computed tomography (to-MOG-ra-fee), or CT, scanning.

Lung function tests measure the size of your lungs; how much air you can breathe in and out; how fast you can breathe air out; and how well your lungs deliver oxygen to your blood. These tests may show how severe your lung disease is and how well treatment is working.

High-resolution CT scanning uses X-rays to create detailed pictures of parts of the body. A CT scan can show whether you have emphysema or another lung condition and how severe it is.

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What Are Lung Function Tests?

Lung function tests, also called pulmonary (PULL-mun-ary) function tests, measure how well your lungs work. These tests are used to look for the cause of breathing problems, such as shortness of breath.

Lung function tests measure:

Doctors use lung function tests to help diagnose conditions such as asthma, pulmonary fibrosis (scarring of the lung tissue) and COPD (chronic obstructive pulmonary disease).

Lung function tests also are used to check the extent of damage caused by conditions such as pulmonary fibrosis and sarcoidosis (sar-koy-DOE-sis). Also, these tests may be used to check how well treatments, such as asthma medicines, are working.


Lung function tests include breathing tests and tests that measure the oxygen level in your blood. The breathing tests most often used are:

These tests may not show what's causing breathing problems. So you may have other tests as well, such as a cardiopulmonary exercise test. This test measures how well your lungs and heart work while you exercise on a treadmill or bicycle.

Two tests that measure the oxygen level in your blood are pulse oximetry and arterial blood gas tests. These tests are also called blood oxygen tests.

Pulse oximetry measures the blood oxygen level using a special light. For an arterial blood gas test, your doctor inserts a needle into an artery, usually in your wrist, and takes a sample of blood. The oxygen level of the blood sample is measured.


Lung function tests usually are painless and rarely cause side effects. You may feel some discomfort during an arterial blood gas test when the needle is inserted into the artery.

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How Is Alpha-1 Antitrypsin Deficiency Treated?

Alpha-1 antitrypsin (AAT) deficiency has no cure. However, the lung diseases associated with this inherited condition have many treatments. Most of these treatments are the same as the ones used for a lung disease called COPD (chronic obstructive pulmonary disease).

If you have symptoms related to AAT deficiency, your doctor may recommend:

Augmentation Therapy

Alpha-1 augmentation therapy is a treatment for people who have AAT-related lung (or skin) disease. This therapy involves getting infusions of AAT protein. This raises the level of the protein in your blood and lungs.

In addition to years of observational studies, published results of two controlled clinical trials confirmed that AAT augmentation therapy significantly reduces the decline in lung density and may therefore reduce the future risk of mortality in patients with AAT deficiency-related emphysema.

People who have AAT deficiency and develop related liver disease will be referred to doctors who treat those diseases.

Future Treatments

Researchers are working on possible treatments that will target the altered AAT genes and replace them with healthy genes. These treatments are in early stages of development.

Researchers also are studying therapies that will allow the misshaped AAT proteins to be released from the liver into the bloodstream. They’re also studying a type of augmentation therapy in which the AAT protein is inhaled instead of injected into a vein.

If you're interested, talk with your doctor about whether any clinical trials of new AAT treatments might benefit you.

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How Can Alpha-1 Antitrypsin Deficiency Be Prevented?

You can't prevent alpha-1 antitrypsin (AAT) deficiency because the condition is inherited (passed from parents to children through the genes). If you inherit two altered AAT genes, you’re more likely to develop AAT-related lung disease. Even so, you may never develop one of the diseases related to the condition.

You can take steps to prevent or delay the lung diseases related to AAT deficiency.

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Living With Alpha-1 Antitrypsin Deficiency

People who have alpha-1 antitrypsin (AAT) deficiency don't always develop serious lung or liver diseases. This means that you can have AAT deficiency and not even know it.

If you already know you have AAT deficiency, you probably also have a related lung or liver disease. Ongoing medical care and lifestyle changes can help you manage your health.

Ongoing Medical Care

If you have AAT deficiency, ongoing medical care is important. Talk with your doctor about how often you should schedule follow-up visits.

Take all of your medicines as prescribed and follow your treatment plan. Get flu and pneumococcus vaccines to protect yourself from illnesses that may worsen your condition.

Get treatment right away for any breathing problems. If treatment includes pulmonary rehabilitation, work with your health care team to learn how to manage your condition and function at your best.

Lifestyle Changes

Quit Smoking and Avoid Lung Irritants

If you smoke, quit. If you don’t smoke, don’t start. Smoking is the leading risk factor for lung disease. Talk with your doctor about programs and products that can help you quit.

Also, try to avoid secondhand smoke and other lung irritants, such as dust, fumes or toxins. Check your living and working spaces for things that may irritate your lungs. Examples include flower and tree pollen, ash, allergens, air pollution, wood-burning stoves, paint fumes and fumes from cleaning products and other household items.

Advise your children to avoid smoking and to stay away from places where they might inhale irritants or toxins. Because AAT deficiency is inherited, your children may have the condition or carry the gene for it. They should do whatever they can to reduce their risk of getting serious lung diseases. (Of course, this is true for anyone—with or without AAT deficiency.)

Follow a Healthy Diet

A healthy diet is an important part of a healthy lifestyle. A healthy diet includes a variety of fruits, vegetables and whole grains.

A healthy diet also includes lean meats, poultry, fish, beans and fat-free or low-fat milk or milk products. A healthy diet is low in saturated fat, trans fat, cholesterol, sodium (salt) and added sugar.

For more information about following a healthy diet, see the National Heart, Lung and Blood Institute’s Aim for a Healthy Weight website, "Your Guide to a Healthy Heart," and "Your Guide to Lowering Your Blood Pressure With DASH." All of these resources include general information about healthy eating.

Also, talk with your doctor about whether it’s safe for you to drink alcohol.

Do Physical Activity Regularly

Try to do physical activity regularly. Talk with your doctor about how much and what types of activity are safe for you.

For more information on physical activity, see the U.S. Department of Health and Human Services' "2008 Physical Activity Guidelines for Americans" and the National Heart, Lung and Blood Institute’s "Your Guide to Physical Activity and Your Heart."

Reduce Stress

Learning how to manage stress, relax and cope with problems can improve your emotional and physical health. Relaxation techniques—such as meditation, yoga, breathing exercises and muscle relaxation—can help you cope with stress.

Emotional Issues and Support

Living with AAT deficiency may cause fear, anxiety, depression and stress. It’s important to talk about how you feel with your health care team. Talking to a professional counselor can also help. If you’re feeling very depressed, your doctor may recommend medicines or other treatments that can improve your quality of life.

Joining a patient support group may help you adjust to living with AAT deficiency. You can see how other people who have the same symptoms have coped with them. Talk with your doctor about local support groups or check with an area medical center.

Support from family and friends also can help relieve stress and anxiety. Let your loved ones know how you feel and what they can do to help you.

Also, be sure to speak to your BioRx Alpha-1 Solutions advisor or Baxter AATmosphere advocate for additional resources and support.

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Cincinnati, OH 45249

Phone: 866-442-4679
Fax: 877-588-8470

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