Alpha-1 Antitrypsin (Serum) Concentration
This test measures the level of Alpha-1 Antitrypsin, a protein produced mainly in the liver that helps protect the lungs and other organs from damage caused by enzymes released during inflammation.
["A1AT levels can help diagnose or monitor conditions affecting your lungs or liver."]
Key facts at a glance
- LOINC
- 24843-5
- Short code
- XR Neck Lat
- Synonyms
- XR Neck Lat
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 22
- Ref high
- 198
- Critical range
- — – 10000 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- xr
- CPT
- 82553
- 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 liver issues, or if you have a family history of conditions like alpha-1 antitrypsin deficiency. It may also be used to check for lung diseases like emphysema or cirrhosis of the liver.
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. Bring any medications you’re currently taking to your appointment.
What Happens During the Test
A healthcare professional will draw blood from a vein in your arm using a small needle. You may feel a slight sting, but it usually only takes a few seconds. The blood sample will be sent to a lab for analysis.
What the Results Mean
Results are compared to a general reference range for healthy adults. Low levels may indicate alpha-1 antitrypsin deficiency, which can lead to lung or liver disease. High levels may be seen in certain liver conditions or during pregnancy.
Reference range
Adult males: 22-198 U/L; Females: 22-198 U/LN/A
No special preparation required. Inform provider of any chest pain or symptoms.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance: Alpha-1 Antitrypsin Deficiency
Short name
Alpha-1 Antitrypsin (A1AT)
Frequently asked questions
What are the normal reference ranges for this test?
How often should I get this test?
Can diet or lifestyle changes affect my A1AT 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 17, 2026. · Read our editorial policy