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Alpha-1 Antitrypsin Deficiency


Alpha-1 antitrypsin is a protein in blood that the liver and lungs use to control the immune response. An alpha-1 antitrypsin deficiency (AAD) means there is too little of the functioning protein in your blood. When bacteria or other harmful substances enter your liver or lungs, cells in your immune system release enzymes to attack them. Alpha-1 antitrypsin prevents this process from going too far and harming healthy tissue as well.

The alpha-1 antitrypsin protein is produced in the liver before being released into your bloodstream on its way to your lungs. In people with the deficiency disorder, the defective protein may accumulate in the liver. This build-up of defective alpha-1 antitrypsin in the liver can lead to diseases, such as cirrhosis.

AAD is a primary cause of childhood liver disease. Adults with AAD are also at risk for unusually severe lung disease, like emphysema, especially if you smoke.

What Are The Symptoms Of AAD?

Not everyone with AAD experiences obvious symptoms. Even if you do have lung symptoms, this does not mean you will experience liver problems too. Liver symptoms with AAD are more likely to appear in childhood, but lung problems from AAD usually appear later in life.

Symptoms in infants often include:

  • a swollen abdomen
  • jaundice
  • loss of appetite

In older children and adults symptoms are:

  • shortness of breath
  • wheezing
  • coughing and producing phlegm
  • recurrent respiratory infections
  • tiredness
  • swelling in the legs
  • weight loss
  • a liver disease with no obvious cause
  • vomiting blood

What Causes AAD? Who Is At Risk?

Alpha-1 antitrypsin deficiency is a hereditary disorder that must be carried by both parents for it to be passed down. There are two genes responsible for normal levels of alpha-1 antitrypsin. Some people inherit two abnormal versions of these genes, one from each parent, and this can result in AAD.

If you have inherited only one faulty gene, you may still have lower than normal levels of the alpha-1 antitrypsin protein. However you would also have a lower risk of developing symptoms. And though you might not experience any symptoms, you could still pass the gene on to your children.

As far as other risk factors, you are more likely to have AAD if you are white and/or have European ancestors. You are also at greater risk if you have relatives with the condition.

Anyone who has AAD and smokes, or is exposed to a lot of dust, chemical fumes, or infections will have weak lungs and be at risk for severe lung problems.

Can I Be Tested For AAD? How Is It Diagnosed?

Your doctor will examine you for signs of breathing difficulties or liver problems. Samples of your blood may be taken to measure your alpha-1 antitrypsin levels and to assess your liver function.

You may have genetic tests to determine whether you have the abnormal genes associated with alpha-1 antitrypsin deficiency.

Tests to measure your lung capacity may be needed. And imaging scans may be used to view the health of your liver and lungs. If there is any cause for concern, a sample of liver tissue might be removed for analysis.

What Are The Treatments for AAD?

Although there is no cure for alpha-1 antitrypsin deficiency, the lung conditions associated with it can be treated in order to prevent or slow their progression.

If you smoke, the most important thing that you can do to improve your condition is to quit. Even if you have been diagnosed with alpha-1 antitrypsin deficiency, but have no symptoms, it is important not to smoke to reduce your chances of developing diseases like emphysema.

Lung problems can be treated using:

  • bronchodilators
  • inhaled steroids
  • antibiotics, if you have an infection
  • vaccines against influenza and pneumonia
  • oxygen therapy
  • pulmonary rehabilitation, where you are taught to manage your condition

Liver problems may require:

  • vitamins and a nutritious diet
  • drugs to reduce the itching associated with jaundice
  • medication to treat fluid retention

Augmentation therapy is a treatment in which alpha-1 antitrypsin protein is infused into a vein. However, there is not enough evidence to show whether or not this treatment is effective, and it is possible it may only benefit some individuals.

In severe cases, a lung or liver transplant may be necessary.

What Is The Outlook For Someone With AAD?

If someone in your family has AAD you may want to have genetic tests to check for it. If the tests are positive, consult with your doctor about what lifestyle changes you can make that could help protect your lungs and liver. i.e. stop smoking, avoid alcoholic beverages, etc.

Although liver and lung diseases brought on by AAD can prove fatal, there are many AAD patients who never show any symptoms and who live perfectly normal lives.

Content licensed from:

Written by: Helen Colledge and Matthew Solan
Medically reviewed : George Krucik, MD

This feature is for informational purposes only and should not be used to replace the care and information received from your health care provider. Please consult a health care professional with any health concerns you may have.
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