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Serum Anti-Saccharomyces cerevisiae Antibodies (ASCA) by Immunoassay

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

This test measures antibodies to *Saccharomyces cerevisiae* (a type of yeast), which may help identify an autoimmune response linked to certain gastrointestinal conditions.

Quick summary

["ASCA antibodies may signal inflammation in the gut, aiding diagnosis of conditions like Crohn’s disease."]

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

Key facts at a glance

LOINC
29949-5
Short code
ENA SS-B Ab Titr Ser ID
Synonyms
ENA SS-B Ab Titr Ser ID
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
immune-diffusion
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 This Test Measures

The ASCA test detects the presence of antibodies produced by your immune system against yeast proteins. These antibodies can indicate an abnormal immune response, often associated with inflammatory bowel diseases such as Crohn’s disease.

Why It Might Be Ordered

Your healthcare provider may recommend this test if you have symptoms like persistent diarrhea, abdominal pain, weight loss, or a history of gastrointestinal issues. It’s sometimes used alongside other tests to help diagnose or monitor conditions like Crohn’s disease.

How the Test Works

A small blood sample is taken from your arm and sent to a lab. The serum is analyzed using an immunoassay method to detect ASCA antibodies. This process identifies whether your immune system has produced these antibodies in response to the yeast protein.

What the Results Mean

Results are qualitative (positive or negative) and not tied to specific numeric ranges. A positive result suggests a higher likelihood of an autoimmune-related gastrointestinal condition, but it’s not definitive on its own. Results should be interpreted by your healthcare provider in the context of your symptoms and other tests.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

ASCA Antibody Test

Frequently asked questions

What are the possible symptoms or conditions this test helps identify?
ASCA antibodies are often elevated in people with Crohn’s disease, an inflammatory bowel condition that primarily affects the lower gastrointestinal tract. They may also appear in other autoimmune or inflammatory gastrointestinal disorders, though less commonly. A positive result doesn’t confirm a diagnosis but may prompt further evaluation.
How often should I get this test?
The frequency depends on your healthcare provider’s recommendations. Some patients with suspected inflammatory bowel disease may have this test as part of an initial evaluation or during follow-up to monitor disease activity. Regular monitoring may be advised if you have a known condition like Crohn’s.
Can I prepare for this test?
No special preparation is needed. You can eat, drink, and take your usual medications as usual. If you’re on blood thinners or have a history of bleeding disorders, inform your provider before the test.
  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