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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 from damage caused by enzymes released during inflammation.

Quick summary

Your A1AT level helps assess lung health and risk for lung diseases like emphysema.

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

Key facts at a glance

LOINC
69125-3
Short code
Deprecated RF Liver Bx needle guide
Synonyms
Deprecated RF Liver Bx needle guide
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
rf
CPT
86430
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 maintaining lung tissue integrity. Low levels can increase the risk of lung diseases, particularly emphysema, which damages the air sacs in the lungs. This test helps doctors identify whether you may be at higher risk for these conditions, especially if you have a family history of lung disease or smoke.

What to Expect Before the Test

No special preparation is needed for this blood test. You may have a small needle inserted into your arm to draw a blood sample. If you’re nervous, let your healthcare provider know so they can help make the process more comfortable.

What the Results Mean

Results are typically reported as a concentration value (e.g., mg/dL). While reference ranges vary by lab, very low levels may indicate a genetic disorder (like Alpha-1 Antitrypsin Deficiency), which can lead to lung or liver problems. High levels may suggest liver disease or certain infections.

Common Reasons for Testing

Doctors may order this test if you have symptoms like chronic cough, shortness of breath, or a history of lung disease. It’s also used in genetic screening for families with a history of A1AT deficiency.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

Alpha-1 Antitrypsin Level

Frequently asked questions

What causes low Alpha-1 Antitrypsin levels?
Low A1AT levels are most commonly caused by a genetic mutation (Alpha-1 Antitrypsin Deficiency). Other rare conditions or liver diseases may also affect production. Smoking or chronic lung infections can temporarily lower levels, but this is usually temporary.
How often should I get this test?
If you have a confirmed diagnosis of Alpha-1 Antitrypsin Deficiency, your doctor may recommend regular monitoring (every 1–3 years) to track lung function and adjust treatment as needed. For routine screening, it’s typically done once or twice in a lifetime if you have a family history of the condition.
Can diet or supplements affect this test?
No, the diet or supplements you take do not directly affect Alpha-1 Antitrypsin levels in blood tests. However, if you have liver disease, certain medications (like some antibiotics or antifungals) may influence liver function indirectly, which could impact protein production.
  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