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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 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
25282-5
Short code
Deprecated S pneum3 IgG 2:1 Ser-Rto
Synonyms
Deprecated S pneum3 IgG 2:1 Ser-Rto
Category
coagulation
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
82784
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 healthcare provider may recommend this test if you have symptoms like chronic cough, shortness of breath, or liver issues, or if you have a family history of conditions like alpha-1 antitrypsin deficiency. It can also be used to check if treatment is working for certain lung or liver diseases.

What to Expect Before the Test

No special preparation is usually needed. You may be asked to fast for 8–12 hours before the test if it involves a blood draw, but this is not always required for this specific test. Bring any medications you’re currently taking to your appointment.

How the Test Works

A small sample of your blood is taken from a vein, usually in your arm. The blood is then sent to a lab where it is analyzed to measure the amount of Alpha-1 Antitrypsin protein present.

What the Results Mean

Results are compared to a general reference range to determine if your levels are low, normal, or high. Low levels may indicate alpha-1 antitrypsin deficiency, which can lead to lung or liver disease, while high levels may be seen in certain liver conditions or genetic variations.

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 Alpha-1 Antitrypsin levels?
Abnormal levels can result from genetic mutations (inherited conditions), liver disease, smoking, or certain medications. If your levels are low, it may indicate a hereditary condition that requires lifelong management, while high levels may be due to liver problems or other factors.
Can lifestyle changes affect my Alpha-1 Antitrypsin test results?
Yes, smoking is known to lower Alpha-1 Antitrypsin levels. Quitting smoking can help improve your levels over time. Avoiding excessive alcohol and managing liver health through diet and exercise may also support normal protein levels.
How often should I get this test if I have a family history of alpha-1 antitrypsin deficiency?
If you have a family history, your healthcare provider may recommend testing at birth or shortly after, followed by regular monitoring—typically every few years or as advised. Follow-up tests help track changes in your levels and guide treatment decisions.
  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