Bakersyeastigafldqnia
The Baker's yeast IgA antibody test detects specific antibodies in your blood that may help diagnose certain digestive conditions, particularly inflammatory bowel disease.
{"This test measures IgA antibodies against Baker's yeast (Saccharomyces cerevisiae)","It is mainly used to help diagnose and differentiate Crohn's disease from other bowel conditions","A positive result suggests possible Crohn's disease, but does not confirm diagnosis alone","Results are interpreted alongside other clinical findings and tests","The test requires a simple blood sample"}
Key facts at a glance
- LOINC
- 63330-5
- Short code
- YEASTIGA
- Synonyms
- Baker's yeast IgA Fld Qn IA
- Category
- chemistry
- Sample
- serum
- Container
- Serum separator tube (SST) or red-top collection tube; transfer serum to a sterile transport tube if needed.
- Units
- N/A
- Ref low
- 10
- Ref high
- 40
- Critical range
- — – 500 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- Immunoassay (e.g., ELISA, FEIA, or similar quantitative immunoassay)
- CPT
- 83516 (Immunoassay for analyte other than infectious agent antibody or infectious agent antigen; qualitative or semiquantitative, multiple step method) or 86671 (Antibody; fungus, not elsewhere specified) depending on payer and lab-specific coding.
- SNOMED
- 122572000 |Measurement of fungal antibody (procedure)| or manufacturer-specific analyte code
- Specimen volume
- 1-2 mL of serum
- Stability
- Serum stable for 7 days at 2-8°C; for longer storage, freeze at -20°C or below for up to 30 days. Avoid repeated freeze-thaw cycles.
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 24–72 hours
- Order
- routine
What is this test?
The Baker's yeast IgA antibody test, also known as ASCA (Anti-Saccharomyces cerevisiae antibody) test, is a blood test that detects the presence of IgA antibodies directed against Saccharomyces cerevisiae, a type of yeast commonly used in baking and brewing. These antibodies develop in some people as an immune response to exposure to Baker's yeast. The test uses immunoassay techniques to measure the level (units/volume) of these antibodies in your blood serum.
Why is this test performed?
This test is primarily ordered to help healthcare providers diagnose and differentiate gastrointestinal conditions, especially inflammatory bowel diseases (IBD). It is most useful in distinguishing Crohn's disease from ulcerative colitis, as ASCA antibodies are more commonly found in patients with Crohn's disease. The test may also be used to assess disease severity or predict complications in patients already diagnosed with Crohn's disease.
What do the results mean?
A positive result indicates the presence of IgA antibodies against Baker's yeast in your blood. This positive result, particularly when combined with other clinical signs and tests, suggests a higher likelihood of Crohn's disease. However, a positive test alone does not confirm a diagnosis - some healthy individuals may also have these antibodies. A negative result means no significant levels of ASCA IgA were detected, which reduces but does not completely rule out the possibility of Crohn's disease. Your healthcare provider will interpret these results along with your symptoms, physical examination, and other diagnostic tests such as colonoscopy, imaging studies, and other laboratory tests.
Reference range
Adult: 10-40 U/LN/A
No special patient preparation is required. Fasting is not necessary prior to specimen collection.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Frequently asked questions
Do I need to fast before this test?
Is this test dangerous or painful?
Can a positive result mean I have Crohn's disease?
Does a negative result mean I don't have Crohn's disease?
What foods should I avoid before the test?
Sources
- 1
- 2
- 3
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.
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 17, 2026. · Read our editorial policy