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Serum or plasma mass concentration of **serine protease inhibitor (e.g., alpha-1 antitrypsin variant or related inhibitor protein)**

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

This test measures the amount of a protein called alpha-1 antitrypsin in your blood. Alpha-1 antitrypsin helps protect your lungs from damage caused by enzymes released during inflammation.

Quick summary

["Alpha-1 antitrypsin levels can help diagnose or monitor lung diseases like emphysema or chronic obstructive pulmonary disease (COPD)."]

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

Key facts at a glance

LOINC
57672-8
Short code
11DC 2D p chal SerPl-mCnc
Synonyms
11DC 2D p chal SerPl-mCnc
Category
hormone
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

What Does This Test Measure?

Alpha-1 antitrypsin is a protein produced mainly in the liver. It acts as an antioxidant and protects lung tissue from damage caused by enzymes released during inflammation. Low levels of alpha-1 antitrypsin can increase your risk of lung diseases, especially if you smoke or have a family history of lung conditions.

Why Might You Need This Test?

Your healthcare provider may order this test if you have symptoms of lung disease, such as shortness of breath, chronic cough, or frequent lung infections. It may also be used to screen family members with a history of alpha-1 antitrypsin deficiency.

What to Expect Before the Test

No special preparation is usually needed. You may be asked to fast for 8–12 hours before the test if it involves drawing blood from a vein. Bring any medications or supplements you’re currently taking to your appointment.

What Happens During the Test?

A healthcare professional will insert a small needle into a vein in your arm to draw blood. The process is quick and typically causes only a brief pinch. The blood sample will be sent to a lab for analysis.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: Alpha-1 Antitrypsin Deficiency and Lung Disease

Short name

Alpha-1 Antitrypsin (AAT) Mass Concentration

Frequently asked questions

Why is this test important for my health?
This test helps identify whether your alpha-1 antitrypsin levels are low, which can indicate a genetic condition called alpha-1 antitrypsin deficiency. Low levels increase your risk of developing lung diseases like emphysema, even if you don’t smoke. Early diagnosis allows for better management and treatment planning.
What are the common symptoms of low alpha-1 antitrypsin levels?
Symptoms may include persistent coughing, shortness of breath, frequent lung infections, or liver problems (less common). Some people with low levels may not have symptoms until lung or liver disease develops. If you have a family history of alpha-1 antitrypsin deficiency, your provider may recommend testing even if you don’t have symptoms.
How is this test different from other blood tests?
Unlike standard blood tests that measure general protein levels, this test specifically focuses on alpha-1 antitrypsin, a protein with a unique role in protecting lung tissue. It is often used alongside other tests, such as lung function tests, to diagnose or monitor conditions like COPD or emphysema.
  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