Chronic obstructive pulmonary disease (COPD) is a group of conditions that cause breathing problems. The two main ones are chronic bronchitis and emphysema.

The American Lung Association estimates that about 16.4 million people in the United States have COPD. The top risk factor is smoking. It’s thought that smoking causes about 90% of COPD cases.

The other 10% of cases are thought to be caused by factors such as:

  • air pollution
  • genetics
  • breathing in fumes and dust

Researchers have identified alpha-1 antitrypsin deficiency (AATD) as a genetic condition that raises your risk of developing COPD. People with AATD have lungs that are more sensitive to damage from environmental factors such as smoking and pollution.

Read on to learn more about the connection between AATD and COPD.

What is AATD?

AATD is a genetic condition inherited from your biological parents that causes your body to produce less alpha-1 antitrypsin protein. It increases your risk of:

  • COPD
  • liver disease
  • panniculitis, a group of conditions that cause painful bumps under your skin
  • vasculitis, which is inflammation of your blood vessels

AATD is caused by a mutation of the SERPINA1 gene. You need to receive a mutated gene from both biological parents to develop AATD.

More than 150 mutations of the SERPINA1 gene have been identified. The two most common mutations are called S and Z mutations. The S mutation is associated with moderately low alpha-1 antitrypsin protein and the Z mutation is associated with very low levels.

AATD is thought to be present in 1 to 4% of people with COPD. If 16.4 million people in the United States have COPD, roughly 164,000 to 656,000 people have AATD.

The primary function of alpha-1 antitrypsin protein is to protect your lungs from inflammation caused by factors such as:

  • tobacco smoke
  • infections
  • other irritants

Research suggests that a type of white blood cell called neutrophils and substances created by neutrophils are key for producing inflammation in the airways of people with COPD. These white blood cells make up about 70% of the white blood cells circulating through your bloodstream.

Neutrophils leave your bloodstream and migrate to your lungs to neutralize infections and irritants. Chronic activation of neutrophils can result in chronic lung inflammation.

Alpha-1 antitrypsin protein protects your lungs from an enzyme called neutrophil elastase that’s produced by neutrophils in the presence of inflammation as part of their defense mechanism. A side effect of this enzyme is the breakdown of lung tissue.

People with AATD produce little to no alpha-1 antitrypsin, which makes them more vulnerable to lung damage.

Symptoms of COPD caused by AATD are the same as COPD without AATD, but they tend to develop earlier in life. COPD symptoms in smokers with AATD tend to begin between the ages of 40 and 50.

They include:

COPD is usually diagnosed with a test called spirometry. During this test, you breathe into a tube connected to a machine that measures how well your lungs are working.

A doctor or healthcare professional may also recommend tests to rule out other conditions. These tests include:

A doctor can tell if you have AATD with a genetic blood test. The Global Initiative for Chronic Obstructive Lung Disease recommends AATD testing for all people with COPD and people with a close family member with AATD.

If you have no symptoms, a doctor might recommend regular follow-ups and good general lifestyle habits such as:

If you don’t smoke and your lung function is declining quickly, you may be eligible for alpha-1 antitrypsin protein replacement therapy. This treatment is the only specific therapy for AATD and involves IV infusion of alpha-1 antitrypsin protein extracted from human donors.

General treatment for COPD symptoms includes:

Learn more about COPD medications.

Very severe cases of COPD are sometimes treated with lung transplants. People with AATD make up about 5% of lung transplants worldwide.

The outlook for people with AATD varies significantly based on factors such as:

  • the specific gene mutation you have
  • lifestyle habits such as smoking and exercise
  • exposure to chemicals and irritants

Studies suggest that AATD is linked to a 4 to 38% increased chance of developing asthma.

Most studies have found no difference in survival rate after lung transplants between people with AATD and COPD and people with only COPD.

The outlook for people with AATD is very poor in those who develop cirrhosis.

Here are some frequently asked questions people have about AATD.

Can testing confirm an AATD?

A doctor can use a blood test to examine your alpha-1 antitrypsin levels and diagnose AATD. The Alpha-1 Foundation encourages testing for people at high risk of AATD such as anyone with COPD, unexplained liver disease, or a family member with AATD.

Can you prevent AATD from leading to COPD?

Early identification of AATD allows you to take early COPD preventive measures such as quitting smoking. Smoking is a key risk factor in developing COPD. Quitting is often difficult, but a doctor can help create a cessation plan that works for you.

Can AATD also cause asthma and other lung conditions?

People with AATD seem to be at an increased risk of developing asthma. AATD has also been linked to bronchiectasis, a condition characterized by damage and widening of the tubes that carry air into your lungs.

Panacinar emphysema is the most specific type of COPD associated with AATD.

AATD is a genetic condition that puts you at risk of developing COPD. People with this condition produce less alpha-1 antitrypsin, a molecule that protects your lungs from damage caused by your immune system as a byproduct of its defense against infections and irritants.

You need to receive an atypical SERPINA1 gene from both biological parents to develop AATD. A doctor can test for AATD with a blood test. If you have severe COPD and AATD, a doctor might recommend alpha-1 antitrypsin replacement therapy.