There are a number of blood tests that are available to investigate and diagnose coeliac and gluten intolerance.
At the Children’s Clinic | Allergy Centre, as part of your specialist consultation,
we will organise these tests for you, if it is indicated.
If you have symptoms that suggest you could be have coeliac disease (see the “Big List” of symptoms), then we will arrange your blood tests. It is important you have these blood tests before you go gluten free. To make a diagnosis of coeliac (celiac) disease, you need to have evidence of gut (intestinal) damage caused by gluten (Note: these tests do NOT test for gluten sensitivity).
Coeliac disease blood tests
The names of these “tissue damage” tests are:
DGP (Diamidated Gliadin Peptide) – IgG and IgG
tTG (tissue TransGlutaminase) – IgA and IgG (on request)
EMA (Endomesial Antibodies) – IgA
These blood tests all detect abnormal antibodies that your immune system makes when the gut is damaged by gluten.
Studies demonstrate that where levels of these antibodies are elevated, more than 95% of patients will be found to have coeliac disease. Some studies state that a high DGP or tTG level is all that is required to make a diagnosis of coeliac disease.
DGP (Deamidated Gliadin Peptide)
This test has been claimed to most accurately identify people with coeliac disease. It detects an immune response to a very specific fragment of the gluten molecule (this fragment is a short peptide of gliadin). Although new test is excellent for detecting coeliac disease, it will not detect gluten sensitivity in people who do not have coeliac disease.
It does NOT replace the IgG-gliadin test.
Value of DGP: If both high, then coeliac disease almost certain.
tTG antibody (also called IgA tissue transglutaminase antibody)
Anti-tTG is a specific antibody made against muscle tissue damage in your small bowel. It is a very sensitive indicator of the small bowel damage that can be caused by the gluten in your diet. High levels of tTG mean that you might have gut damage (coeliac disease). It is currently recommended that you confirm the likelihood of gut damage by having a small bowel biopsy (by endoscopy).
Value of tTG: If very high, then coeliac disease almost certain. If slightly high, then maybe celiac.
EMA (Endomesial Antibodies)
This is an older test and becoming less popular. Nevertheless, it is quite sensitive at detecting the gut tissue damage of celiac disease.
Value of EMA: If positive, then high chance of celiac disease.
If these coeliac blood tests are “normal” – this does NOT rule out gluten-sensitivity (see the gluten tests item).
Currently, it is still recommended that coeliac disease is confirmed by small bowel biopsy (upper endoscopy).