What is an Alpha-1 Antitrypsin Test?

aat test, aat deficiency test, aat deficiencyTo understand what an Alpha-1 Antitrypsin (AAT) test is, you should first familiarize yourself with AAT and what having a deficiency in AAT means to you and your family.

What is AAT and AAT Deficiency?

AAT is a protective protein made by the liver. You need AAT to help protect your lungs and maintain normal lung function. Healthy lungs contain an enzyme called neutrophil elastase. Normally, this enzyme helps the lungs digest damaged, aging cells and bacteria; a process that promotes healing of your lung tissue. But neutrophil elastase doesn’t know when to shut itself off and eventually attacks the lung tissue instead of healing it. That’s where AAT comes in – to destroy the enzyme before it can cause further damage to healthy lung tissue. When there’s a deficiency in AAT, destruction of lung tissue continues, which sometimes leads to emphysema in adults. AAT deficiency can also cause liver disease in people of any age.[1]

How do I get AAT Deficiency?

AAT deficiency is a genetic condition, meaning it’s inherited from your parents when you’re born. At birth, you inherit two sets of AAT genes – one from each of your parents. If both sets of AAT genes are normal, you won’t have the disease. You’ll only have AAT deficiency if both sets of AAT genes are abnormal. If only one set of AAT genes is abnormal and the other is normal, you’ll be a carrier of AAT deficiency, and not have the disease itself.[2]

If you’ve been diagnosed with AAT deficiency, it’s important that you reach out to your doctor about having additional family members, including each of your children, tested for AAT deficiency with the Alpha-1 Antitrypsin test. For those who don’t have children yet, but plan to have them in the future, it’s recommended they speak to a genetic counselor.2

Signs and Symptoms of AAT Deficiency

Initial symptoms of AAT deficiency include cough, mucus production and wheezing. At first, symptoms are sporadic, and oftentimes, when wheezing is the most prominent symptom, patients are told they have asthma. If patients go to the doctor for recurrent episodes of cough, they may be given multiple courses of antibiotics and diagnosed with conditions such as sinusitis, post-nasal drip or gastroesophageal reflux disorder.[3]

Eventually, shortness of breath becomes the most dominant symptom of AAT deficiency. It may initially only be present with strenuous activity. Over time, shortness of breath limits even mild activity.3

One thing that differentiates lung disease caused by AAT deficiency and lung disease brought about by other causes is that patients with AAT deficiency frequently develop shortness of breath at an earlier age than do smokers with emphysema and normal AAT levels.3

It should be noted that cigarette smoking hastens the progression of lung disease in patients with AAT deficiency, with symptoms developing approximately 10 years earlier in regular smokers who have AAT deficiency.3

The Alpha-1 Antitrypsin Test

Genetic testing is the most accurate way to confirm AAT deficiency. A blood test that checks AAT protein levels in your blood can also be used. If the level is much lower than normal, it’s probable that you have AAT deficiency.3

Who Should Get Tested?

According to the 2016 Clinical Practice Guidelines published in the Journal of the COPD Foundation, the following groups of people should be tested for AAT deficiency:[4]

Parents, siblings and children, as well as extended members, of people who have an abnormal gene for AAT deficiency should obtain genetic counseling and get tested for the condition. For testing family members, the AAT protein level laboratory test alone is not recommended because it doesn’t fully typify the risk of disease from AAT deficiency. For family testing or diagnostic testing of people with symptoms, genotyping is recommended for people with certain types of alleles.3


Augmentation therapy is available only for people with AAT-related lung disease. This involves getting regular infusions – over the course of a lifetime – of the AAT protein. Although more research is needed to confirm its benefit, some research suggests that it slows the development of AAT deficiency in people who don’t have severe disease.3

Although there is no cure for AAT deficiency, there are many treatments available for lung disease related to the condition. Most treatment for lung disease caused by AAT deficiency are the same used for chronic obstructive pulmonary disease (COPD) and include:3

  • Inhaled bronchodilators – to relax and widen your airways
  • Inhaled steroids – to reduce swelling and inflammation in your airways
  • Supplemental oxygen – to increase oxygen levels in your blood
  • Flu and pneumonia vaccines – to protect you from illnesses that can worsen your condition
  • Pulmonary rehabilitation – to learn how to manage your lung disease in order for you to function at your best
  • Lung transplant – may be an option for those with severe disease who haven’t responded well to standard lung disease treatment

For more information about AAT deficiency and the Alpha-1 Antitrypsin deficiency test, contact the Alpha-1 Foundation at 1-877-228-7321 or your primary care provider.

[1] American Lung Association. Alpha-1 Antitrypsin Deficiency. Accessed March 30, 2018.

[2] National Heart, Lung and Blood Institute. Alpha-! Antitrypsin Deficiency. Accessed March 30, 2018.

[3] Izaguirre Anariba, Dora E., MD, MPH. Alpha-1 Antitrypsin Deficiency. Updated March 18, 2018.

[4]Sandhaus RA, Turino G, Brantly ML, et al. The diagnosis and management of alpha-1 antitrypsin deficiency in the adult. Chronic Obstr Pulm Dis. 2016; 3(3): 668-682. doi: http://doi.org/10.15326/jcopdf.3.3.2015.0182


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