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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 and other organs from damage caused by enzymes released during inflammation.

Quick summary

["Alpha-1 Antitrypsin helps prevent lung and liver damage; low levels may indicate genetic disorders or chronic inflammation."]

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

Key facts at a glance

LOINC
13143-3
Short code
Deprecated S pneum4 Ab sp1 Ser-aCnc
Synonyms
Deprecated S pneum4 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 Might Be Ordered

Your healthcare provider 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 Alpha-1 Antitrypsin deficiency. It may also be done to monitor lung or liver disease progression.

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 on blood thinners, let your provider know before the test.

What the Results Mean

Results help determine if your A1AT levels are low, which could indicate a genetic condition affecting lung or liver health. Your provider will discuss findings in relation to your symptoms and medical history.

Common Reasons for Testing

This test is often used to diagnose or monitor Alpha-1 Antitrypsin deficiency, a genetic disorder linked to lung diseases like emphysema or chronic bronchitis, and liver diseases such as cirrhosis.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

A1AT Serum

Frequently asked questions

How often will I need this test?
Your provider will determine the frequency based on your condition. For example, people with known deficiency may need monitoring every few years, while others may need it more often if symptoms worsen.
What if my results are low?
Low levels may require further genetic testing or treatment options, such as enzyme replacement therapy. Your provider will guide you on next steps based on your specific situation.
Can lifestyle changes affect my A1AT levels?
While lifestyle factors like smoking or chronic infections can contribute to lung inflammation, they do not directly alter A1AT levels. Focus on managing symptoms and following your provider’s advice for overall health.
  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