Rodney Ford

If you have symptoms that suggest you could be have celiac disease or are gluten sensitive, the next step is to arrange to get your blood tests. It is important you have these blood tests before you go gluten free.

Please keep on gluten until you have had your blood tests.

Currently available blood tests:

Tissue damage tests: to look for celiac disease

Step one is to look for evidence of gut damage: this is to make a diagnosis of celiac (coeliac) disease.  These "tissue damage" tests are called:

• DGP-IgG (Diamidated Gliadin Peptide – IgG)
• tTG (tissue TransGlutaminase) - IgA
• DPG-IgA (Diamidated Gliadin Peptide – IgA)
• EMA (Endomesial Antibodies) - IgA

Celiac disease is defined as the gut damage caused by gluten. When this happens, there is an over-reaction of the immune system in the gut. A harmful immune reaction is generated in the gut mucosa. This tissue injury involves inflammatory cells and the production of antibodies.  These "tissue damage" tests can pick this up.

Studies demonstrate that where levels of these antibodies are elevated, more than 95% of patients will be found to have coeliac disease.  Not surprisingly, there are now claims that a high DGP or tTG level is all that is required to make a diagnosis of celiac disease.

DGP (Deamidated Gliadin Peptide)

This is a new type of gliadin test is being manufactured by Inova Diagnostics. It has been developed to more accurately identify people with coeliac disease.  Eventually, it is likely to overtake the tTG test because it is excellent at finding those people who have gluten gut damage. This test detects an immune response to a very specific fragment of the gluten molecule (this fragment is a short peptide of gliadin). This new test is excellent for detecting coeliac disease (in fact it seems more reliable that the tTG test), but it will not detect gluten sensitivity in people who do not have celiac disease.

It will not pick up the people who have the other symptoms of The Gluten Syndrome.  It does not replace the IgG-gliadin test.

Value of DGP: If both high, then celiac disease almost certain.

tTG antibody (also called IgA tissue transglutaminase antibody)

The tTG antibody test is a tissue damage test. 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 (celiac 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 celiac 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 positivie, then high chance of celiac disease.

To look for gluten-sensitivity

Step two is to look for evidence of gluten harm: this is to make the diagnosis of gluten-sensitivity (reactions to gluten without the gut damage).

• Anti gliadin antibody – IgG
• Anti gliadin antibody – IgA

The conflict of the IgG-gliadin test

There is disagreement surrounding the interpretation of the gliadin antibody test.  It is found in elevated levels in about 10% of the population. 

To summarise, beginning in the 1990s, the anti-gliadin IgG antibody test (often referred to as the IgG-gliadin test) was used to verify suspicion of celiac disease. However, it is  a poor predictor of celiac disease.  By contrast, the "tissue damage" antibodies (see above) are set off by bowel tissue damage and are excellent predictors of celiac disease.

There are two opposing schools of thought. First, the medical establishment, represented by the gastroenterologists, has concluded that the gluten blood tests are inaccurate and misleading (in relation to celiac disease). Their total focus is on the gut damage: and justify their position with the fact that gluten (gliadin) blood tests are poor predictors of who has the tissue damage caused by celiac disease.

This is true, but they then go on to make a serious error of logic. They say that because the gluten tests are not useful in detecting celiac disease, consequently, these gluten tests are not good for anything, and should be abandoned.

Dr Rodney Ford's data shows another interpretation:

The IgG-gliadin test is a gluten test

Research shows that the IgG-gliadin antibody test is valuable for detecting people who are reacting adversely to gluten (but who do not have celiac disease).

The relationship between patient complaints and high levels of gluten antibodies has been widely investigated.  Dr Ford's research has shown that high levels of gluten antibodies accurately predict a beneficial response to a gluten-free diet.

High IgG-gliadin antibody levels are indicative of an immunological reaction to gluten, which can manifest as significant poor health – The Gluten Syndrome.

The books that tell you much more about this are:

• Are You Gluten Sensitive?
• The Gluten Syndrome.