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Serum or Plasma Alpha-1 Antitrypsin (A1AT) 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 or injury.

Quick summary

["Alpha-1 Antitrypsin helps prevent lung disease and other chronic conditions by protecting tissues from breakdown."]

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

Key facts at a glance

LOINC
31777-6
Short code
C trach Ag Spec Ql
Synonyms
C trach Ag Spec Ql
Category
chemistry
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 This Test Might Be Ordered

Your healthcare provider may order this test if you have symptoms like chronic cough, shortness of breath, or lung problems that could be linked to low Alpha-1 Antitrypsin levels. It’s also checked in people with a family history of conditions like emphysema or chronic obstructive pulmonary disease (COPD).

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 serum/plasma is collected. Bring any medications you’re taking to your appointment.

How the Test Is Performed

A blood sample is drawn from a vein, usually in your arm. The sample is sent to a lab for analysis using an immunoassay method to measure the protein concentration.

What the Results Mean

Results are compared to a standard range, but exact values can vary by lab. Low levels may indicate genetic disorders or conditions affecting lung health, while high levels might be seen in certain liver diseases or infections.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Low Alpha-1 Antitrypsin levels are strongly linked to alpha-1 antitrypsin deficiency, a genetic condition that can cause lung diseases like emphysema or liver disease. Regular monitoring is important for those at risk to prevent progression.

Short name

Alpha-1 Antitrypsin Level

Frequently asked questions

What causes low Alpha-1 Antitrypsin levels?
Low levels are often due to genetic mutations passed down through families. Other rare causes may include certain liver diseases or conditions that reduce protein production.
How long does it take to get results?
Results are typically available within 1–3 business days, depending on your lab’s processing time.
Can I eat or drink before this test?
If fasting is required, avoid food and liquids (except water) for 8–12 hours before the blood draw. If no fasting is needed, you can eat and drink normally.
  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