Alpha-1 Antitrypsin Deficiency
What is alpha-1 antitrypsin deficiency?
Alpha-1 antitrypsin deficiency (a1AD) is an inherited condition, which occurs as a result of an individual lacking a protein known as alpha-1 antitrypsin. Alpha-1 antitrypsin (a1AT) is made by the liver and found in the bloodstream and its main function is to protect the lungs from damage caused by an enzyme known as neutrophil elastase. A1AT is needed to regulate the activity of the enzyme, so that it is able to remove bacteria in the lungs to prevent infection, without causing damage to the lungs. Without the a1AT protein, the neutrophil elastase can harm healthy lung tissue.
Alpha-1 antitrypsin deficiency is relatively rare and affects 1 in 3000-4000 people in the UK. The condition is inherited, meaning that parents must pass it on to their child.
What are the symptoms of alpha-1 antitrypsin deficiency?
Symptoms of alpha-1 antitrypsin deficiency do not usually develop until the age of 40, despite the fact that a patient is born with the disease. It is possible for symptoms to develop earlier than this, but it is uncommon; however, if you smoke, you are more likely to develop symptoms at an early age.
The most common effect of alpha-1 antitrypsin deficiency is emphysema, a form of chronic obstructive pulmonary disease (known as COPD).
Symptoms of emphysema include:
Not all people with a1AT deficiency will develop COPD. There are genetic variations of the disease and only people with very low levels of a1AT are likely to develop COPD.
Some children with alpha-1 antitrypsin deficiency experience liver failure, but this is uncommon. Symptoms may include:
- An enlarged liver.
- Pale stools.
Most people with a1AT deficiency suffer scarring of the liver but it is rare for patients to develop liver disease.
How is alpha-1 antitrypsin deficiency diagnosed?
In many cases, alpha-1 antitrypsin deficiency is confused with asthma. However, a simple blood test can be used to confirm a diagnosis of a1AT deficiency, with the blood sample used to analyse and determine the levels of a1AT in the blood. If a child is diagnosed with a1AT deficiency, other family members may be advised to have a blood test.
What causes alpha-1 antitrypsin deficiency?
Alpha-1 antitrypsin deficiency is an inherited condition, which means that it is passed on from parents to their child. The inheritance pattern for a1AT deficiency is more complex than other inherited disorders. In order for a person to have the disease, they must inherit a faulty gene, known as the Pi (protease inhibitor), from one or both of their parents. If an individual inherits a faulty gene from both their parents, there is a 90% chance that they will have abnormally low levels of a1AT in their blood. If they inherit one faulty gene they will still be at risk of lung and liver damage, and 40% of people with one faulty gene have low levels of a1AT.
Treatment for alpha-1 antitrypsin deficiency
There is no one specific treatment for alpha-1 antitrypsin deficiency, but there are treatments available to help ease symptoms.
- Using an inhaler.
- Oxygen therapy.
- Medication to improve lung function.
People with alpha-1 antitrypsin deficiency should avoid smoking, as this will increase the risk of developing COPD at an early age and accelerate the damage to lung tissue. Passive smoking should also be avoided and as a1AT deficiency can also increase the risk of liver problems, patients are advised to drink in moderation.
Eating a healthy, balanced diet is very important to boost your immune system and prevent infections and illnesses and you should try to eat plenty of fruit and vegetables. It may also be advisable to have an annual flu vaccination and steer clear of friends or relatives if they have colds, coughs or chest infections. Exercising on a regular basis will also help to keep you fighting fit.
What is the outlook for alpha-1 antitrypsin deficiency?
The outlook for people with a1AT deficiency is generally positive and many people do not even know that they have the condition until they reach middle age. However, the condition can be managed very effectively using medication and self-help techniques. Research into treatment is ongoing.