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Alpha-1 Antitrypsin (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 and other organs from damage caused by enzymes released during inflammation.

Quick summary

["A1AT levels can help diagnose or monitor conditions affecting your lungs or liver."]

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

Key facts at a glance

LOINC
93732-6
Short code
IgE Tear-aCnc
Synonyms
IgE Tear-aCnc
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
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 like chronic cough, shortness of breath, or liver problems. It’s also used to screen for genetic conditions that affect A1AT production, such as Alpha-1 Antitrypsin Deficiency, which can lead to lung disease or cirrhosis.

What to Expect Before the Test

No special preparation is needed, but you may be asked to fast for 8–12 hours before the test if it involves drawing blood from your arm. Wear comfortable clothing and bring any medications you’re currently taking.

How the Test Is Performed

A healthcare provider will insert a needle into a vein in your arm to draw a small amount of blood. The blood sample is then sent to a lab for analysis using an immunoassay method to measure A1AT concentration.

Possible Results and Their Meaning

Results are typically reported as a mass concentration in grams per deciliter (g/dL). Low levels may indicate a genetic disorder, while very high levels could be due to liver disease or other conditions. Your doctor will interpret results in the context of your symptoms and medical history.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Alpha-1 Antitrypsin (A1AT)

Frequently asked questions

What causes abnormal A1AT levels?
Abnormal A1AT levels can result from genetic mutations (e.g., Alpha-1 Antitrypsin Deficiency), chronic liver disease, or certain infections. Smoking can also lower A1AT levels over time.
How often should I get this test?
Your doctor will determine the frequency based on your symptoms, medical history, and risk factors. For example, people with a family history of Alpha-1 Antitrypsin Deficiency may need testing more often.
Can lifestyle changes affect A1AT levels?
While smoking is the most well-known lifestyle factor that lowers A1AT levels, quitting smoking can help stabilize or increase levels over time. Diet and exercise may indirectly support liver health but do not directly alter A1AT concentrations.
  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