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Total Antitrypsin Activity in Serum (Alpha-1 Antitrypsin Activity)

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

This test measures the activity level of alpha-1 antitrypsin, a protein that helps protect your lungs and liver from damage caused by enzymes released during inflammation.

Quick summary

["Alpha-1 antitrypsin helps prevent lung and liver damage; low levels may indicate genetic disorders or chronic lung diseases."]

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

Key facts at a glance

LOINC
33575-2
Short code
C trach I Ab Titr Ser IF
Synonyms
C trach I Ab Titr Ser IF
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
if
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 recommend this test if you have symptoms of lung diseases like chronic obstructive pulmonary disease (COPD) or emphysema, liver problems, or if you have a family history of alpha-1 antitrypsin deficiency. It can also be part of a general health check for those at risk of these conditions.

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. Stay hydrated unless instructed otherwise.

How the Test Is Performed

A healthcare professional will draw blood from a vein in your arm using a needle. The blood sample will be sent to a lab for analysis of alpha-1 antitrypsin activity levels.

What the Results Mean

Results are typically reported as a numerical value representing the activity level of alpha-1 antitrypsin in your serum. Lower than expected levels may signal a genetic disorder or conditions affecting lung or liver function.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Low alpha-1 antitrypsin activity is strongly linked to alpha-1 antitrypsin deficiency, a genetic condition that increases the risk of lung diseases (e.g., emphysema) and liver cirrhosis. High levels may be seen in acute inflammation or certain liver conditions. Regular monitoring is important for those with a known deficiency.

Short name

Alpha-1 Antitrypsin Activity

Frequently asked questions

What causes abnormal alpha-1 antitrypsin activity?
Abnormal results can be due to genetic mutations (alpha-1 antitrypsin deficiency), chronic lung diseases (like COPD), liver diseases, or certain infections or inflammatory conditions. If you have a family history of the disorder, your provider may screen you early.
How often should I get this test?
If you have alpha-1 antitrypsin deficiency, your provider may recommend testing every few years or more frequently if you develop symptoms of lung or liver disease. Follow-up depends on your specific condition and healthcare plan.
Can diet or lifestyle changes affect this test result?
Diet or lifestyle changes generally do not directly alter alpha-1 antitrypsin activity levels, but they can influence conditions like COPD or liver disease that might indirectly affect test results. Avoid smoking and follow medical advice for managing related health issues.
  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