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Serum or plasma concentration of antichymotrypsin

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

This test measures the amount of antichymotrypsin, a protein that helps protect tissues from damage caused by enzymes. It may be used to assess lung function or detect certain inflammatory conditions.

Quick summary

["Antichymotrypsin helps monitor lung health and inflammation."]

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

Key facts at a glance

LOINC
94694-7
Short code
nAChR Ab Ser IA-sCnc
Synonyms
nAChR Ab Ser IA-sCnc
Category
coagulation
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ia
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 Might This Test Be Ordered?

Your healthcare provider may order this test to evaluate lung function, especially if you have symptoms like shortness of breath, chronic cough, or a history of lung diseases such as chronic obstructive pulmonary disease (COPD) or cystic fibrosis. It can also help diagnose or monitor conditions like pneumonia, lung infections, or inflammatory lung diseases.

What to Expect Before the Test

No special preparation is typically needed. You may have a small needle inserted into your arm to draw blood. If you’re using blood thinners, let your provider know before the test.

What the Test Results Mean

Lower than expected levels might suggest lung damage, inflammation, or certain lung diseases. Higher levels could indicate conditions like acute respiratory distress syndrome (ARDS) or severe infections. Your provider will discuss results in the context of your overall health.

Common Conditions Monitored

This test is often used to monitor lung health in conditions like COPD, cystic fibrosis, or after lung injuries. It may also help track responses to treatments for inflammatory lung diseases.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: Antichymotrypsin is a marker of lung tissue integrity. Low levels can indicate lung damage, inflammation, or certain infections. It’s particularly useful in diagnosing or managing chronic lung conditions where other tests may be less informative.

Short name

Antichymotrypsin Level

Frequently asked questions

What does a low antichymotrypsin level mean?
A low level may signal lung damage, inflammation, or conditions like chronic lung disease, infections, or lung injuries. Your provider will review the result with your symptoms and other tests.
Can diet affect antichymotrypsin levels?
Dietary factors generally do not significantly impact antichymotrypsin levels, as it’s a protein produced by the body. However, chronic inflammation or underlying health conditions may influence results.
Is this test painful?
The blood draw is typically mild discomfort for a few seconds, similar to a standard blood test. Most people experience minimal pain afterward.
  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