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Alpha-1 Antitrypsin (A1AT) Serum 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.

Quick summary

["A1AT helps prevent lung disease and liver problems; low levels may indicate genetic disorders or chronic lung conditions."]

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

Key facts at a glance

LOINC
56387-4
Short code
Sheep Sorrel IgG4-mCnc
Synonyms
Sheep Sorrel IgG4-mCnc
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
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, wheezing, or shortness of breath, especially if they suggest lung diseases like emphysema or chronic obstructive pulmonary disease (COPD). It may also be checked in people with a family history of Alpha-1 Antitrypsin deficiency, liver disease, or unexplained lung problems.

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.

How the Results Are Used

Low levels of A1AT can indicate genetic disorders like Alpha-1 Antitrypsin deficiency, which increases risk for lung disease or liver problems. High levels may be seen in certain liver conditions or during pregnancy.

Common Conditions Linked to A1AT Levels

Abnormally low A1AT is most strongly linked to Alpha-1 Antitrypsin deficiency, a genetic condition that can cause lung diseases (like emphysema) and liver disease. High levels may be associated with acute liver inflammation or certain medications.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

A1AT Level

Frequently asked questions

What might cause my A1AT level to be low?
Low A1AT levels are most commonly due to Alpha-1 Antitrypsin deficiency, a genetic disorder passed through families. Other rare causes include certain liver diseases or conditions that damage the liver. If your levels are low, your doctor may recommend genetic testing or further evaluation of lung or liver health.
Could my A1AT level be high?
High A1AT levels can occur in conditions like acute liver inflammation (hepatitis), certain infections, or during pregnancy. They may also be seen with some medications. If your levels are high, your doctor may check for underlying liver issues or other causes.
Do I need to do anything special if my A1AT level is abnormal?
If your results are abnormal, follow your doctor’s advice. For low levels, they may recommend monitoring lung function, liver tests, or genetic counseling. For high levels, they may check for liver disease or other conditions. Lifestyle changes (like quitting smoking) can sometimes help manage symptoms linked to A1AT deficiency.
  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