Version July 2025
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What is alpha-1 antitrypsin testing? —
These are tests to check the level of alpha-1 antitrypsin ("AAT") in the blood. AAT is a protein made by the liver. It helps protect the lungs and liver from damage.
Some people have something called "AAT deficiency." This is a disorder where their body doesn't make enough AAT. It can run in families. People with AAT deficiency are more likely to have serious health problems like emphysema, other types of chronic obstructive pulmonary disease ("COPD"), or liver diseases.
Alpha-1 antitrypsin testing is usually done on a sample of blood. The sample might also be tested for abnormal AAT proteins or genes.
Why might I get alpha-1 antitrypsin testing? —
Your doctor might order these tests if you have a:
●Condition that could be caused by AAT deficiency, such as COPD or liver disease
●Close relative with AAT deficiency
How do I prepare for alpha-1 antitrypsin testing? —
These tests are done as a blood test. After you give a blood sample, it is tested in a lab.
●In some cases, the staff will prick your finger to get a blood sample.
●In other cases, you need to get a "blood draw." Your doctor or nurse will tell you where to go for this.
It might help to wear a short-sleeve shirt to your blood draw appointment. This makes it easier for the person drawing your blood to get to your arm.
What happens during a blood draw? —
A needle is used to take a small amount of blood from your arm (figure 1). Collecting the blood only takes a few minutes.
Tell the person who takes your blood:
●If you take "blood thinner" medicines or have a bleeding problem – They will make sure your bleeding is under control before you leave.
●If you have a latex allergy – Some of the supplies used for blood draws might contain latex.
●If you have a preferred arm to use
Most of the time, getting blood taken does not cause problems. You might have a little soreness or bruising where the needle went in.
What do my results mean? —
Your doctor or nurse will tell you when to expect your results, and will contact you with them. Or if you use an online "patient portal," you might get an alert there when your results are ready.
If your alpha-1 antitrypsin test shows any abnormal results, your doctor or nurse will talk to you about what to do next. They might need to do more tests to figure out the cause.
If you do have a health problem, your doctor will work with you to come up with a treatment plan.
