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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 from damage caused by enzymes released during inflammation.

Quick summary

["Alpha-1 Antitrypsin helps prevent lung disease and supports immune function."]

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

Key facts at a glance

LOINC
13132-6
Short code
Deprecated S pneum4 Ab Ser-aCnc
Synonyms
Deprecated S pneum4 Ab 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 Is This Test Done?

Your healthcare provider may order this test if you have symptoms of lung disease (such as chronic cough or shortness of breath), a family history of Alpha-1 Antitrypsin deficiency, or if you have conditions like emphysema or chronic bronchitis. It may also be used to monitor liver function or assess risk for certain diseases.

What Does a Low Level Mean?

Low levels of Alpha-1 Antitrypsin can indicate a genetic deficiency, which may increase your risk of lung diseases like emphysema or chronic obstructive pulmonary disease (COPD). It can also affect liver health, though this is less common.

What Does a High Level Mean?

High levels are generally not clinically significant unless associated with conditions like liver disease or certain inflammatory states. Abnormal results often prompt further evaluation.

Sample Collection and Preparation

A blood sample is drawn from a vein, usually in your arm. The blood is processed to separate serum (the liquid part) for testing. This test does not require fasting.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Alpha-1 Antitrypsin

Frequently asked questions

Alpha-1 Antitrypsin deficiency is a genetic condition that can lead to progressive lung damage and liver disease. Early detection through testing helps manage symptoms and prevent complications.
Alpha-1 Antitrypsin levels are measured using an immunoassay method, which detects the protein in your serum. Results are compared to standard reference ranges to determine if levels are low, normal, or high.
What should I do if my test results are abnormal?
If your results show low Alpha-1 Antitrypsin levels, your healthcare provider may recommend genetic testing to confirm a deficiency. They may also suggest lifestyle changes, medications, or referrals to specialists for lung or liver care.
How often should I get this test?
If you have a known Alpha-1 Antitrypsin deficiency, your provider may recommend regular monitoring to track changes in your levels or symptoms. Follow their guidance for follow-up testing.
  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