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Alpha-1 Antitrypsin, Serum/Plasma — Mass Concentration

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

This blood test measures alpha-1 antitrypsin, a liver-made protein that helps protect the lungs from inflammation.

Quick summary

["The result can help identify unusually low or high alpha-1 antitrypsin levels, but it is interpreted alongside other findings."]

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

Key facts at a glance

LOINC
1829-1
Short code
A1AT SS SerPl-mCnc
Synonyms
A1AT SS 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?

Alpha-1 antitrypsin is a protein made mainly by the liver. It travels in the blood and helps limit damage from inflammation in the lungs.

Why might I need this test?

This test may be ordered if a person has unexplained chronic lung disease, liver disease, or a family history of alpha-1 antitrypsin deficiency. It may also be used to monitor a patient with an established low alpha-1 antitrypsin level.

How is the test performed?

A blood sample is collected, and the laboratory measures the concentration of alpha-1 antitrypsin in serum or plasma. The result is usually interpreted with the person's symptoms, medical history, and other laboratory tests.

How do I prepare for the test?

No special preparation is usually needed. Follow your clinician's instructions about fasting, medications, and timing, especially if the test is being repeated to monitor your health.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Alpha-1 Antitrypsin

Frequently asked questions

What does alpha-1 antitrypsin do?
It is a protective protein that limits inflammation-related damage, particularly in the lungs. The liver produces most of it.
Does a low result mean I have alpha-1 antitrypsin deficiency?
A low result can suggest the condition, but diagnosis may also require genetic testing or protein phenotyping. Your clinician can explain the follow-up needed.
Can alpha-1 antitrypsin levels be high?
Yes. Levels can rise during acute inflammation, infection, pregnancy, or with certain liver conditions, so the result must be interpreted in context.
  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