Antitrypsin (Alpha-1) Activity in Serum
This test measures the level of alpha-1 antitrypsin, a protein that helps protect your lungs and liver from damage caused by enzymes released during inflammation or injury.
["Alpha-1 antitrypsin helps prevent lung disease and liver damage; low levels may indicate genetic risk or deficiency."]
Key facts at a glance
- LOINC
- 89454-3
- Short code
- Ob Attend Note
- Synonyms
- Ob Attend Note
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- obstetrics-attending
- 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 Is This Test Done?
Your doctor may order this test if you have a family history of alpha-1 antitrypsin deficiency, symptoms like chronic cough, wheezing, or liver issues, or if you have conditions like emphysema or cirrhosis. It can also help assess lung or liver health in people with known genetic risks.
What Does a Result Mean?
Results are typically compared to a reference range for healthy individuals. Very low levels may suggest a genetic deficiency that increases your risk for lung diseases or liver problems. High levels might be seen in certain inflammatory conditions, but this is less common for this test.
Sample Collection and Preparation
A blood sample is drawn from a vein in your arm. The blood is processed to separate serum (the liquid part after clotting), which is then tested for alpha-1 antitrypsin activity using an immunoassay method.
What to Expect Before the Test
No special preparation is needed, but you may be asked to avoid certain medications that could affect results, such as some anti-inflammatory drugs. Fasted or non-fasted blood draws are usually acceptable.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
Alpha-1 Antitrypsin Activity
Frequently asked questions
Alpha-1 antitrypsin deficiency is a genetic condition that can lead to chronic lung diseases (like emphysema) or liver diseases (like cirrhosis). Early detection through this test allows for monitoring, lifestyle adjustments, or potential treatments to manage symptoms and slow disease progression.
If your result is significantly lower than expected, it may indicate alpha-1 antitrypsin deficiency. Your doctor will discuss your risk, symptoms, and next steps, which may include genetic counseling or referral to a specialist.
While diet and lifestyle can influence overall health, they typically do not directly affect alpha-1 antitrypsin levels in this test. However, managing conditions like smoking or chronic inflammation may indirectly support lung and liver health.
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