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Anti-Saccharomyces cerevisiae antibodies (ASCA) – Immunoglobulin G (IgG) class

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

This test measures the presence of antibodies against *Saccharomyces cerevisiae* yeast, which may help identify certain autoimmune conditions affecting the digestive system.

Quick summary

["ASCA-IgG helps diagnose inflammatory bowel disease (IBD) by detecting immune responses linked to gut inflammation."]

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

Key facts at a glance

LOINC
25290-8
Short code
Deprecated S pneum14 IgG sp1 Ser-aCnc
Synonyms
Deprecated S pneum14 IgG sp1 Ser-aCnc
Category
coagulation
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 Is ASCA-IgG Testing Used For?

ASCA-IgG is primarily used to support the diagnosis of **inflammatory bowel disease (IBD)**, particularly **Crohn’s disease**, by detecting specific antibodies that may indicate chronic inflammation in the digestive tract. It is not a standalone test but often used alongside other markers like calprotectin or endoscopic findings.

How Is This Test Performed?

A blood sample is drawn from a vein in your arm. The serum portion is then tested for ASCA-IgG antibodies using an **immunoassay** method, which detects the presence of these antibodies in your bloodstream.

Why Might You Need This Test?

Your healthcare provider may recommend ASCA-IgG testing if you have symptoms like persistent abdominal pain, diarrhea, weight loss, or a history of IBD. It helps differentiate between types of IBD or assess immune-related gut inflammation.

What Do Results Mean?

Results are qualitative (positive/negative) rather than quantitative, meaning they indicate whether antibodies are present rather than their exact concentration. A positive result suggests a higher likelihood of Crohn’s disease, but it is not definitive alone.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

ASCA-IgG

Frequently asked questions

Why was this test ordered?
Your doctor may have ordered this test to investigate symptoms like chronic abdominal pain, unexplained diarrhea, or a suspected autoimmune condition affecting your digestive system.
What does a positive result mean?
A positive result suggests a higher likelihood of Crohn’s disease, but it is not definitive. Your doctor will consider clinical symptoms, other test results, and imaging findings for a full diagnosis.
Can this test be done at home?
No, this test requires a blood sample collected in a clinical setting by a healthcare professional.
  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