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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 helps prevent lung disease and liver problems; low levels may indicate genetic risk or conditions like emphysema."]

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

Key facts at a glance

LOINC
13151-6
Short code
Deprecated S pneum9 Ab sp1 Ser-aCnc
Synonyms
Deprecated S pneum9 Ab sp1 Ser-aCnc
Category
coagulation
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 healthcare provider may order this test if you have symptoms of lung disease (such as chronic cough or shortness of breath), liver problems, or if you have a family history of Alpha-1 Antitrypsin deficiency. It may also be used to monitor treatment for known conditions affecting these proteins.

What to Expect Before the Test

No special preparation is needed. You may have a small needle inserted into your arm to draw blood, which usually takes a few minutes. Avoid eating or drinking for 8–12 hours before the test if instructed by your provider.

What the Test Results Mean

Results are compared to a standard range for healthy adults. Very low levels may suggest genetic deficiency, while very high levels could indicate liver disease or other conditions. Your provider will discuss results with you in the context of your overall health.

Common Conditions Linked to A1AT Levels

Low A1AT levels are strongly linked to Alpha-1 Antitrypsin deficiency, which can cause chronic lung diseases like emphysema or liver cirrhosis. High levels may be associated with conditions like chronic obstructive pulmonary disease (COPD) or liver disorders.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

A1AT Serum

Frequently asked questions

How long does it take to get my test results?
Results are typically available within 1–3 business days, depending on your lab. Your provider will contact you once they are ready.
Can I eat or drink before this test?
Follow your provider’s instructions—usually, you should fast for 8–12 hours before the blood draw, but confirm with them to avoid confusion.
What if my A1AT level is outside the normal range?
If your results are abnormal, your provider will explain what it means for you and may recommend further testing or treatments, such as enzyme replacement therapy for 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