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Alpha-1 Antitrypsin (A1AT) in Serum

Published: August 9, 2026Updated: August 16, 2026

This test measures the level of Alpha-1 Antitrypsin, a protein produced by the liver that helps protect the lungs and other organs from damage caused by enzymes released during inflammation.

Quick summary

["Alpha-1 Antitrypsin helps prevent lung disease and liver problems; low levels may signal genetic risk or liver issues."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
41810-3
Short code
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Synonyms
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Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ct
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 symptoms of lung diseases like chronic obstructive pulmonary disease (COPD) or emphysema, or if you have a family history of Alpha-1 Antitrypsin deficiency. It may also be checked before surgeries or treatments that could affect your immune or respiratory systems.

What to Expect Before the Test

No special preparation is needed. You’ll provide a blood sample, usually drawn from your arm. Avoid smoking or strenuous activity for a few hours before testing if instructed by your healthcare provider.

What the Results Mean

Results help determine if your Alpha-1 Antitrypsin levels are low, which could indicate a genetic condition or liver disease. Very low levels may increase your risk for lung diseases or liver problems over time.

Common Causes of Abnormal Results

Low levels of Alpha-1 Antitrypsin can be caused by genetic mutations, liver disease, or chronic inflammation. High levels may occur in certain liver conditions or during pregnancy.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

A1AT Serum

Frequently asked questions

How is Alpha-1 Antitrypsin tested?
This test is typically performed using an immunoassay method, which detects the protein in your serum. Results are compared to standard reference ranges to assess your levels.
What should I do if my results are low?
If your levels are low, your doctor may recommend further testing, lifestyle changes, or monitoring to manage potential risks. Genetic counseling may also be advised if a family history of deficiency is present.
Can diet or supplements affect this test?
Dietary changes or supplements alone won’t change Alpha-1 Antitrypsin levels, but they may influence overall health. Follow your doctor’s advice regarding medications or supplements that could interact with test results.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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