Alpha-1 Antitrypsin (A1AT) Serum Level
This test measures the level of Alpha-1 Antitrypsin, a protein produced mainly in the liver that helps protect the lungs from damage caused by enzymes released during inflammation or infection. Low levels may indicate a genetic disorder or liver disease.
["Low Alpha-1 Antitrypsin can increase your risk of lung disease or liver problems."]
Key facts at a glance
- LOINC
- 31649-7
- Short code
- Deprecated S pneum6 Ab sp2 Ser-aCnc
- Synonyms
- Deprecated S pneum6 Ab sp2 Ser-aCnc
- Category
- coagulation
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
Why This Test Might Be Ordered
Your doctor may recommend this test if you have a family history of Alpha-1 Antitrypsin deficiency, symptoms of lung disease (such as chronic cough or shortness of breath), or signs of liver issues. It may also be used to monitor lung function in people with known genetic risk factors.
What to Expect During the Test
A blood sample will be taken from a vein, usually in your arm. You may feel a slight pinch, but it shouldn’t cause significant discomfort. The test involves drawing a small amount of blood into a tube, which is then sent to a lab for analysis.
Preparation for the Test
No special preparation is needed for this test. You can eat and drink normally before your appointment. If you are on blood thinners or have a history of bleeding disorders, let your doctor know before the test.
Possible Results and Interpretation
Results are compared to a reference range that varies by lab. Low levels of Alpha-1 Antitrypsin may suggest a genetic disorder or liver disease. High levels might be seen in certain liver conditions or during pregnancy. Your doctor will discuss the results in the context of your overall health.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Alpha-1 Antitrypsin deficiency is a genetic condition that can lead to chronic lung diseases like emphysema or chronic obstructive pulmonary disease (COPD) and liver diseases such as cirrhosis. Early diagnosis is important for managing symptoms and preventing complications. Regular monitoring may be recommended if you have a family history or symptoms.
Short name
A1AT Serum
Frequently asked questions
What causes low Alpha-1 Antitrypsin levels?
Can lifestyle changes affect Alpha-1 Antitrypsin test results?
How often should I get this test if I have a family history?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy