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Serum or plasma *Alpha-1 Antitrypsin* (A1AT) levels by immunodiffusion/line blot

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

This test measures the amount of Alpha-1 Antitrypsin, a protein that helps protect your lungs and liver from damage caused by enzymes released during inflammation.

Quick summary

["A1AT helps prevent lung diseases like emphysema and liver disorders; 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
85095-8
Short code
3-PGDH IgG Ser Ql Line blot
Synonyms
3-PGDH IgG Ser Ql Line blot
Category
glucose
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
line-blot
CPT
82784
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 like chronic cough, shortness of breath, or unexplained liver issues. It’s also used to screen family members of those with known A1AT deficiency, a genetic condition passed from parents to children.

What to Expect Before the Test

No special preparation is needed. You’ll provide a blood sample, usually drawn from your arm. If you’re on blood thinners, let your doctor know before the test.

What the Results Mean

Results help determine if your A1AT levels are low (which may increase your risk for lung or liver disease) or within normal ranges. Your doctor will discuss findings with you based on your symptoms and medical history.

Common Causes of Abnormal Results

Low A1AT levels can occur due to genetic mutations, chronic lung diseases, or liver conditions. High levels may be seen in certain infections or liver diseases.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

This test is critical for diagnosing Alpha-1 Antitrypsin deficiency, a genetic disorder that can lead to progressive lung disease (like emphysema) or liver cirrhosis. Early detection allows for monitoring and potential interventions to manage symptoms and slow disease progression.

Short name

A1AT Screening/Confirm

Frequently asked questions

What does an abnormal A1AT level mean?
An abnormal result may indicate a genetic predisposition to lung or liver disease. Your doctor will review your results with you and may recommend further testing or lifestyle adjustments.
Can diet or supplements affect A1AT levels?
Dietary changes alone won’t alter A1AT levels, but certain medications (like some antibiotics or liver disease treatments) may influence results. Always follow your doctor’s advice.
Is this test painful?
The blood draw is quick and may cause slight discomfort, but most people tolerate it well. If you’re anxious, ask your doctor about numbing cream or other options.
  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