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Alpha-1 Antitrypsin (A1AT) Serum Concentration

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

This test measures the amount 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

["A1AT levels help assess lung health and risk for conditions like emphysema or chronic lung diseases."]

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

Key facts at a glance

LOINC
107502-7
Short code
AChR Ab SerPl Fetus Ql
Synonyms
AChR Ab SerPl Fetus Ql
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 doctor may order this test if you have symptoms of lung disease, a family history of Alpha-1 Antitrypsin deficiency, or if you’re being evaluated for conditions like chronic obstructive pulmonary disease (COPD) or liver disease. It can also help monitor treatment progress or screen for genetic risks.

What to Expect Before the Test

No special preparation is usually needed, but you may be asked to fast for 8–12 hours before the test if it involves drawing blood. Wear a comfortable shirt for easy access to your arm.

How the Test Works

A healthcare provider will insert a needle into your arm to draw a small amount of blood. The sample is then sent to a lab for analysis using an immunoassay method to measure your A1AT protein levels.

What the Results Mean

Results are compared to a reference range to identify if your levels are low, normal, or high. Low levels may indicate a genetic disorder, while very high levels could be linked to certain liver conditions or other health factors.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

A1AT Serum Level

Frequently asked questions

What Are Common Causes of Abnormal Results?
Low A1AT levels are most commonly associated with Alpha-1 Antitrypsin deficiency, a genetic condition that increases the risk of lung diseases like emphysema. High levels may occur with liver disease, certain medications, or inflammation.
How Often Should I Get This Test?
Your doctor will determine the frequency based on your medical history, symptoms, and risk factors. For those with a known deficiency, tests may be done periodically to monitor progression or treatment effects.
Can I Avoid This Test If I Don’t Have Symptoms?
Yes, if you don’t have symptoms of lung disease or a known genetic risk, your doctor may not recommend routine testing. However, if you have a family history of A1AT deficiency, screening may be advised.
  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