Skip to content

Alpha-1 Antitrypsin Phenotype, Serum/Plasma

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

A blood test that identifies the forms of alpha-1 antitrypsin protein present, which can help evaluate inherited deficiency and related lung or liver conditions.

Quick summary

["This test identifies inherited alpha-1 antitrypsin protein variants that may affect lung and liver health."]

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

Key facts at a glance

LOINC
32769-2
Short code
A1AT Phenotyp SerPl-Imp
Synonyms
A1AT Phenotyp SerPl-Imp
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?

The alpha-1 antitrypsin phenotype test determines which versions, or protein variants, of alpha-1 antitrypsin are present in a blood sample. Alpha-1 antitrypsin is a protein that helps protect the lungs from inflammation.

Why might I need this test?

This test may be ordered for unexplained chronic lung disease, including early-onset emphysema, or for unexplained liver disease. It may also be used to investigate a family history of alpha-1 antitrypsin deficiency or to help guide genetic counseling.

How is the test performed?

A serum or plasma sample is obtained from a blood draw and analyzed in the laboratory to identify the alpha-1 antitrypsin protein pattern or variants. If needed, the result may be confirmed with another laboratory method or a genetic test.

How do I prepare for the test?

No special preparation or fasting is usually required. Follow any instructions provided by the testing laboratory, and tell your healthcare professional if a recent illness, infection, or liver disease may affect the interpretation.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Alpha-1 antitrypsin phenotype

Frequently asked questions

Is this the same as an alpha-1 antitrypsin level test?
No. A phenotype test identifies the different protein variants present, while an alpha-1 antitrypsin level test measures the total amount of the protein in the blood.
Does an abnormal result mean I will definitely have lung or liver disease?
No. Some variants increase risk but do not guarantee disease. Your healthcare professional will interpret the result alongside symptoms, examination findings, and other tests.
Should my family members be tested?
Testing may be recommended for first-degree relatives, particularly after a variant is identified. A healthcare professional or genetic counselor can explain when and how family testing should be done.
  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