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Plasma/Serum Alpha-1 Antitrypsin (A1AT) Mass 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 from damage caused by enzymes released during inflammation or injury.

Quick summary

["A1AT helps prevent lung disease and supports immune function; low levels may indicate genetic risk or liver disease."]

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

Key facts at a glance

LOINC
22758-7
Short code
PAI1 Ag PPP IA-mCnc
Synonyms
PAI1 Ag PPP IA-mCnc
Category
chemistry
Sample
plasma
Container
Lavender-top (EDTA) or Green-top (Heparin)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ia
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 Matters

Alpha-1 Antitrypsin (A1AT) is crucial for protecting lung tissue from damage. Low levels can increase the risk of chronic lung diseases like emphysema, especially if you have a family history of genetic A1AT deficiency.

What to Expect Before the Test

No special preparation is needed. You may eat and drink normally. Your blood will be drawn from a vein, usually in your arm, and you may feel a brief pinch or slight discomfort.

Common Causes of Abnormal Results

Low levels of A1AT can be caused by genetic mutations, chronic liver disease, or certain medications. High levels may occur in conditions like acute inflammation or infections.

What Your Results Mean

Results are used to assess lung health, diagnose genetic disorders, or monitor liver function. Your doctor will interpret the results in the context of your overall health and symptoms.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

A1AT Level

Frequently asked questions

Could my A1AT levels affect my lung health?
Yes, if you have a genetic mutation linked to low A1AT, you may be at higher risk for lung diseases like emphysema, even if you don’t smoke. Your doctor may recommend monitoring or treatments to manage symptoms.
What if my test results are abnormal?
Abnormal results may require further testing, such as genetic evaluation or additional bloodwork, to determine the cause. Your healthcare provider will discuss next steps with you based on your symptoms and medical history.
How often should I get this test?
If you have a known genetic risk for A1AT deficiency, your doctor may recommend regular monitoring. Otherwise, this test is typically ordered only when symptoms or concerns suggest it’s needed.
  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