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Alpha-1 antitrypsin (AAT) deficiency is a rare inherited disorder that can lead to serious chronic obstructive pulmonary disease (COPD). While there's no cure, treatments and lifestyle changes can help you manage your symptoms and protect your lungs from further damage.  

COPD is a group of lung conditions that includes emphysema and chronic bronchitis. The most common symptoms people have as lung disease develops due to AAT deficiency are:

  • Wheezing
  • Shortness of breath
  • A chronic cough with phlegm 
  • Repeated colds
  • Pneumonia 

Ronald Crystal, MD, chairman of genetic medicine at Weill Cornell Medicine, said people are most often diagnosed with AAT deficiency after they visit their doctor due to breathlessness.

“They go up a flight of stairs and they're short of breath. They walk up the subway stairs and they're short of breath. They try to run, say after a bus or something, and they're short of breath,” says Crystal, also a pulmonary doctor who has treated more than 500 people with the disease. 

"Most people ascribe it to, say, ‘Well, I'm getting old, I'm out of shape, I'm overweight,’ and they sort of put it off until it continues and it gets worse.

But the longer you wait to get treatment, the more damage that can be done to your lungs.

What Is Alpha-1 Antitrypsin? 

Alpha-1 antitrypsin is a protein made by your liver that moves throughout your body in your bloodstream. One of its main functions is to protect your body from an enzyme called neutrophil elastase. Your immune system produces this enzyme to help fight inflammation or infection. But if it's left unchecked by AAT, it can harm the fragile tissues in your lungs.

Without enough AAT, the neutrophil elastase damages more and more of your lung cells. As the damage continues through the years, lung disease can develop.  

The situation is worse for people who smoke. Smoking causes emphysema and other symptoms to develop much faster. 

“If you're not a cigarette smoker and you have alpha-1 antitrypsin deficiency, you don't develop the emphysema until age 55 or so,” says Crystal. “But if you are a cigarette smoker, or if you've been a cigarette smoker, you can develop the disease at ages 35 to 40.”

Can AAT Deficiency Affect Other Parts of My Body?

While rare, AAT deficiency can also cause liver disease including cirrhosis and liver cancers. People usually develop lung disease or liver disease, but not both, says Crystal.  

When AAT affects your liver, it's because the alpha-1 protein produced there has an abnormal shape. That means it can't get out and builds up in your liver. Over time, this causes damage to the organ, Crystal says.

How Is ATT Deficiency Diagnosed? 

If you're in your 30s, 40s, and even early 50s and develop signs of COPD, such as shortness of breath, get tested for AAT deficiency.

Your doctor will start by doing a full examination and listening to your breathing.

If you have emphysema or other COPD not caused by AAT deficiency, it tends to affect the upper and middle lobes of your lungs. If your lung disease is due to AAT, it's more likely to affect the lower areas of your lungs, Crystal says. 

While your doctor may notice signs of AAT deficiency, you need a blood test to confirm the diagnosis.

Your doctor may also recommend imaging tests, such as X-rays and CT scans, to examine your lungs and liver to check for damage.

What Are the Treatments for AAT Deficiency?

There are several treatments available to address the symptoms of COPD.  But augmentation therapy (sometimes also called replacement therapy) is the only specific therapy for AAT deficiency. It uses alpha-1-antitrypsin protein from healthy human donors to increase your levels of the protein. You get it in regular IV infusions. 

The goal is to increase the alpha-1-antitrypsin protein in your body, so it can protect your lungs from the neutrophil elastase enzyme. 

While this treatment doesn’t cure AAT deficiency or fix damage already done, it can help protect your lungs from further harm.

“You can't give back lung function. You can't give back normal air sacs. What you can do is protect them from deteriorating,” says Crystal, who as former chief of the pulmonary branch of the National Heart, Lung, and Blood Institute helped develop the therapy.

While Crystal offers the treatment to his patients with both early-onset and severe disease, some doctors have differing views on who should get the therapy and when. Some only give it to people with moderate lung disease, not those with early-onset or severe disease. 

“My argument for treating somebody who has severe disease is as long as they're sitting in your office talking with you, they obviously have enough lungs to protect. And so why not treat them?” he said. “So I treat everybody. As long as they have evidence of emphysema, either by lung function and or CT scan, I treat them.”


What Else Can I Do for AAT Deficiency?

If you have AAT deficiency, your doctor may prescribe an inhaler, oxygen therapy, or antibiotics to help with COPD flare-ups.

it’s especially important not to smoke. Talk to your doctor about how you can exercise safely, especially if you have symptoms of lung disease.

If you have signs of liver disease, limit alcohol.

Crystal says it's essential for those with AAT deficiency to stay up-to-date on vaccines, including the annual flu shot. 

“Make sure you get your pneumococcal vaccination and make sure, of course, you get COVID vaccinations because these people are much more susceptible if they have pneumonia or viral pneumonia,” he says. “Vaccinations, vaccinations, vaccinations – they are so important.” 

Show Sources

Photo Credit: yodiyim / Getty Images


Ronald Crystal, MD, chairman of genetic medicine, Weill Cornell Medicine, New York, NY. 

Alpha-1 Foundation: “Lung Disease.” 

Alpha-1 Foundation: “Treatment.” 

Cleveland Clinic: “Alpha-1 Antitrypsin Deficiency.” 

American Lung Association: “Treating and Managing Alpha-1 Antitrypsin Deficiency: How AAT Deficiency is Treated.”