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Serum Anti-Saccharomyces Cerevisiae Antibody (ASCA) Immunoassay

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

This test measures antibodies in your blood that target *Saccharomyces cerevisiae* (a type of yeast), often linked to inflammatory bowel disease (IBD).

Quick summary

["ASCA helps doctors assess possible IBD, particularly Crohn’s disease, by detecting immune system responses to gut bacteria."]

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

Key facts at a glance

LOINC
38487-5
Short code
IgA Ser-aCnc
Synonyms
IgA Ser-aCnc
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

What Does This Test Measure?

ASCA detects specific antibodies your immune system produces in response to *Saccharomyces cerevisiae* (a common gut yeast). These antibodies may indicate chronic inflammation in the digestive tract, often seen in conditions like Crohn’s disease.

Why Might You Need This Test?

Your doctor may order this test if you have symptoms like persistent diarrhea, abdominal pain, weight loss, or a history of IBD. It helps distinguish between different types of IBD or rule out other causes of gut inflammation.

How Is the Test Performed?

A blood sample is taken from a vein in your arm. The sample is sent to a lab where antibodies against the yeast are measured using an immunoassay method.

What Are Possible Results?

Results are qualitative (positive/negative) and not tied to a specific numeric range. A positive result suggests a higher likelihood of ASCA-related inflammation, but it’s not definitive alone. Your doctor will interpret results in the context of your symptoms and other tests.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

ASCA Antibody Test

Frequently asked questions

What Does a Positive Result Mean?
A positive ASCA test may indicate an immune response linked to Crohn’s disease or other inflammatory conditions. It’s not a definitive diagnosis but can guide treatment decisions, such as targeting specific gut bacteria in therapy.
What If Results Are Negative?
A negative result means no detectable antibodies to this yeast, which may reduce suspicion for ASCA-driven inflammation. However, other tests or conditions could still explain your symptoms.
How Often Should I Get This Test?
Your doctor will determine the need for retesting based on your symptoms, treatment response, or other diagnostic needs. Follow-up may depend on your overall health and medical history.
  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