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Alpha-1 Antitrypsin (A1AT) Serum Protein Concentration by Immunoassay

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 and other organs from damage caused by enzymes released during inflammation.

Quick summary

["A1AT helps prevent lung and liver diseases; low levels may indicate genetic risk or underlying conditions."]

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

Key facts at a glance

LOINC
88204-3
Short code
RSV A RNA Corn/Cnjt Ql NAA+probe
Synonyms
RSV A RNA Corn/Cnjt Ql NAA+probe
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
probe-amp-tar
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 This Test Is Done

Your doctor may order this test if you have symptoms of lung diseases (like chronic obstructive pulmonary disease or emphysema), liver problems, or if you have a family history of Alpha-1 Antitrypsin deficiency. It can also be used to monitor treatment or assess risk in certain conditions.

What to Expect Before the Test

No special preparation is needed. You may have a small needle inserted into your arm to draw blood. If you’re nervous, let your healthcare provider know—some people find it helpful to bring a support person.

What the Results Mean

Results help determine if your A1AT levels are low, normal, or high. Low levels may suggest a genetic disorder linked to lung or liver disease. Your doctor will discuss findings in the context of your symptoms and medical history.

Common Conditions Linked to A1AT Levels

Low A1AT levels are most strongly associated with Alpha-1 Antitrypsin Deficiency, a genetic condition that can cause chronic lung diseases (like emphysema) and liver disease. High levels may be seen in certain inflammatory conditions or liver disorders.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: Alpha-1 Antitrypsin Deficiency

Short name

A1AT Serum

Frequently asked questions

What symptoms might this test help identify?
This test helps identify if you have a genetic predisposition to lung diseases (e.g., shortness of breath, chronic cough) or liver issues (e.g., jaundice, fatigue). Early detection can guide treatment and prevent complications.
How often should I get this test?
If you have a family history of Alpha-1 Antitrypsin Deficiency, your doctor may recommend testing as part of routine screening. If results are abnormal, follow-up testing or monitoring may be needed based on your symptoms and risk factors.
What if my results are low?
If your results are low, your doctor may recommend genetic testing to confirm Alpha-1 Antitrypsin Deficiency. They may also suggest lifestyle changes (like quitting smoking) or refer you to a specialist for further evaluation or management of potential lung or liver risks.
  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