Serum or Plasma Alpha-1 Antitrypsin (A1AT) Concentration
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.
["Alpha-1 Antitrypsin helps maintain lung health and can be low in conditions like emphysema or chronic inflammation."]
Key facts at a glance
- LOINC
- 85804-3
- Short code
- FLUAV H5 Ag Titr Islt HAI
- Synonyms
- FLUAV H5 Ag Titr Islt HAI
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- hai
- 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 Is Done
Your doctor may order this test if you have symptoms of lung disease, such as shortness of breath, chronic cough, or a history of smoking. It may also be used to monitor lung function in people with known genetic conditions affecting this protein.
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 blood draw if your test involves a fasting sample. Bring any medications you’re currently taking to your appointment.
How the Test Is Performed
A healthcare provider will draw blood from a vein in your arm using a small needle. The blood sample is then sent to a lab for analysis using an immunoassay method to measure Alpha-1 Antitrypsin levels.
What the Results Mean
Results are compared to standard reference ranges to determine if your levels are within normal limits, low, or high. Low levels may indicate genetic disorders or lung diseases, while high levels could suggest liver problems or certain inflammatory conditions.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Low Alpha-1 Antitrypsin levels are strongly linked to conditions like alpha-1 antitrypsin deficiency, which can lead to chronic lung diseases like emphysema. Doctors may also use this test to diagnose or monitor liver diseases, infections, or inflammatory conditions affecting protein production.
Short name
Alpha-1 Antitrypsin Level
Frequently asked questions
What causes low Alpha-1 Antitrypsin levels?
How often should I get this test?
Can diet 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