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Alpha-1 Antitrypsin (A1AT) Serum Concentration

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 from damage caused by enzymes released during inflammation.

Quick summary

["A1AT levels can help diagnose or monitor lung diseases like emphysema or chronic obstructive pulmonary disease (COPD)."]

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

Key facts at a glance

LOINC
17977-0
Short code
LA Area A4C
Synonyms
LA Area A4C
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
us-d-a-c
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 Matters

Alpha-1 Antitrypsin (A1AT) is crucial for maintaining lung and liver health. Low levels can increase the risk of lung diseases, such as emphysema, where the lungs lose elasticity and become damaged over time. This test helps identify genetic mutations that may lead to reduced A1AT production, which can cause chronic inflammation and tissue damage.

What to Expect Before the Test

No special preparation is needed for this blood test. You may have a small needle inserted into your arm to draw a blood sample. If you’re nervous, let your healthcare provider know—they can help make the process more comfortable.

How the Test Works

Blood is collected from a vein in your arm and sent to a lab. The lab uses an immunoassay method to measure the amount of Alpha-1 Antitrypsin protein in your serum. This helps determine if your levels are within the normal range or if further evaluation is needed.

Possible Results and Next Steps

If your results are low, your doctor may recommend genetic testing to check for mutations linked to A1AT deficiency. They might also monitor your lung function closely if you have a history of lung disease. Normal results mean your A1AT levels are likely healthy, but follow-up may still be advised if you have symptoms of lung issues.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: Alpha-1 Antitrypsin Deficiency

Short name

A1AT Serum

Frequently asked questions

What causes low Alpha-1 Antitrypsin levels?
Low A1AT levels are often caused by genetic mutations passed down through families. These mutations can prevent the liver from producing enough of the protein, leading to chronic inflammation in the lungs and liver over time. Some people may also develop low levels due to liver disease or certain medications.
How does this test help doctors?
This test helps doctors identify if you have Alpha-1 Antitrypsin deficiency, which can increase your risk of lung diseases like emphysema. Early detection allows for better management and prevention strategies, such as monitoring lung function or lifestyle adjustments to slow disease progression.
Can lifestyle changes affect A1AT levels?
While lifestyle changes like quitting smoking or avoiding lung irritants (like air pollution) can help protect lung health, they generally do not directly change A1AT levels. However, maintaining a healthy lifestyle can reduce inflammation and support overall lung function, especially if you have a genetic predisposition to A1AT deficiency.
  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