Serum or Plasma Alpha-1 Antitrypsin (A1AT) Concentration by Immunoassay
This test measures the amount of Alpha-1 Antitrypsin, a protein produced by the liver that helps protect the lungs from damage caused by enzymes released during inflammation.
["A1AT helps prevent lung diseases and supports immune function; low levels may indicate genetic disorders or liver issues."]
Key facts at a glance
- LOINC
- 53926-2
- Short code
- C trach rRNA Vag Ql NAA+probe
- Synonyms
- C trach rRNA Vag Ql NAA+probe
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- probe-amp-tar
- 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 healthcare provider may recommend this test if you have symptoms like chronic cough, shortness of breath, or if you have a family history of conditions like alpha-1 antitrypsin deficiency, which can affect the lungs or liver. It may also be checked before surgeries or treatments that could increase lung exposure to harmful substances.
What to Expect Before the Test
No special preparation is usually needed, but you may be asked to fast for 8–12 hours before the test if your blood is drawn early in the morning. Avoid smoking or strenuous activity for 24 hours before testing, as these can affect lung function and protein levels.
How the Test Is Performed
A blood sample is taken from a vein in your arm using a needle. The blood is then sent to a lab for analysis using an immunoassay method, which detects the presence and concentration of Alpha-1 Antitrypsin in your serum or plasma.
What the Results Mean
Results are compared to a reference range, but exact values can vary by lab. Low levels of Alpha-1 Antitrypsin may suggest genetic deficiency, liver disease, or chronic lung conditions. High levels might be seen in certain liver disorders or during pregnancy.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Alpha-1 Antitrypsin deficiency is a genetic disorder that can lead to lung diseases (like emphysema) or liver cirrhosis. Early detection helps manage symptoms and plan treatments, such as enzyme replacement therapy or lung function monitoring. Your provider will discuss results in the context of your health history and symptoms.
Short name
A1AT Level
Frequently asked questions
What does a low Alpha-1 Antitrypsin level mean?
How often should I get this test?
Can diet or lifestyle changes affect Alpha-1 Antitrypsin levels?
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