Skip to content

Alpha-1 Antitrypsin, Serum/Plasma — Mass Concentration

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

A blood test that measures the amount of alpha-1 antitrypsin, a protein that helps protect the lungs and liver from damage.

Quick summary

["This test helps evaluate alpha-1 antitrypsin levels, which may be low in inherited deficiency or elevated with certain inflammatory and liver conditions."]

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

Key facts at a glance

LOINC
1827-5
Short code
A1AT MS SerPl-mCnc
Synonyms
A1AT MS SerPl-mCnc
Category
liver
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

What is this test?

This blood test measures the concentration of alpha-1 antitrypsin in serum or plasma. This protein is made mainly by the liver and helps protect lung tissue from inflammation.

Why might I need this test?

Your doctor may order this test if you have unexplained chronic lung disease, liver disease, or a family history of alpha-1 antitrypsin deficiency. It can also help assess a low level found during another evaluation.

How is the test performed?

A blood sample is collected, and a laboratory measures the amount of alpha-1 antitrypsin in the fluid portion of the blood. The laboratory may use an immunoassay or another validated method.

How do I prepare for the test?

This test usually does not require fasting or special preparation. Tell your healthcare professional about any medicines or health conditions that could affect the result, and follow the instructions provided by the testing laboratory.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Alpha-1 antitrypsin

Frequently asked questions

Does this test diagnose alpha-1 antitrypsin deficiency?
Not by itself. A low level can suggest deficiency, but confirming the diagnosis may require repeat testing, phenotyping, or genetic testing.
Why was my alpha-1 antitrypsin level checked?
It is often checked when someone has unexplained lung or liver disease, especially with a family history of similar conditions. Your doctor can explain the reason for your specific test.
Can inflammation affect the result?
Yes. Alpha-1 antitrypsin can rise during inflammation, infection, or pregnancy, and some liver conditions can also increase the level. Results should therefore be interpreted in the context of your 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