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Alpha-1 Antitrypsin (Serum) Concentration

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

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

Quick summary

["A1AT levels can help identify genetic risks for lung diseases or liver problems."]

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

Key facts at a glance

LOINC
13162-3
Short code
Deprecated S pneum23 Ab sp2 Ser-aCnc
Synonyms
Deprecated S pneum23 Ab sp2 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 doctor may order 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 monitor treatment for certain lung diseases.

What to Expect Before the Test

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

What the Results Mean

Lower than normal levels may indicate a genetic condition that increases your risk for lung diseases (like emphysema) or liver disease. Higher levels may be seen in certain infections or liver conditions, but this is less common.

Common Causes of Abnormal Results

Abnormally low A1AT levels are most often linked to a genetic disorder. Other conditions, like chronic liver disease or certain infections, can sometimes cause lower-than-normal levels, but this is less typical.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

Alpha-1 Antitrypsin (A1AT) Level

Frequently asked questions

What does a low A1AT level mean?
A low A1AT level suggests a higher risk for lung diseases like emphysema or chronic obstructive pulmonary disease (COPD), especially if you have a family history of the condition. It may also raise concerns for liver disease, though further testing would be needed to confirm.
What does a high A1AT level mean?
High A1AT levels are usually not directly harmful but can sometimes indicate conditions like chronic liver disease or certain infections. If your doctor finds this result, they may recommend further evaluation to rule out underlying issues.
Is this test covered by insurance?
Most insurance plans cover this test if it’s ordered as part of a diagnostic evaluation for suspected lung or liver conditions. However, it’s best to check with your insurance provider or ask your doctor for specifics.
  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