When coeliac disease is suspected, the first step would be a blood test.
- Tissue transglutaminase 2 IgA and IgG (anti-TG2)
- Endomysial IgA (EMA)
- It is important to test the total IgA level as well when doing these tests, as a general IgA deficiency can give false normal results
- Before doing the test the person should be eating normal amounts of gluten, as gluten avoidance can cause false negative tests
- If the levels of antibodies are high, celiac disease is very likely
The diagnosis may be confirmed by a biopsy of the small bowel taken during a gastroscopy. This involves swallowing an instrument with a camera on the tip. A small piece of intestinal lining (the biopsy) will then be examined under a microscope. In Coeliac disease we see flattening of the finger-like structures of the intestinal lining that absorb nutrients, and a build-up of inflammatory cells in the lining.
Endoscopy pic, normal pic, coeliac pic