(Anti-Saccharomyces Cerevisiae Antibody – IgA)
A marker to support diagnosis of Inflammatory Bowel Disease (IBD)

What is the ASCA IgA Test?

The ASCA IgA test detects the presence of IgA class antibodies against Saccharomyces cerevisiae — a type of yeast commonly found in the gut and in food (like baker’s yeast).

High levels of ASCA IgA are associated with Crohn’s Disease, a type of Inflammatory Bowel Disease (IBD).

Why is the Test Done?

✅ Helps in the differential diagnosis between:

• Crohn’s Disease (usually ASCA positive)

• Ulcerative Colitis (usually ASCA negative)

✅ Supports diagnosis in patients with:

• Chronic abdominal pain

• Diarrhea

• Unexplained weight loss

• Gastrointestinal inflammation

✅ Often used alongside:

• ASCA IgG

• p-ANCA (Perinuclear Anti-Neutrophil Cytoplasmic Antibodies)

• Endoscopy and colon biopsy