Gluten Sensitivity / Coeliac Blood Tests
N.B. The “patient” must be eating a normal gluten-laden diet at the time of the tests. If for any reason the person has already eliminated gluten before taking the blood tests, then at least 4 slices of bread (or pasta or wheat bran etc.) per day must be eaten for at least 2 months prior to the tests. If this is not done, the test results will be inconclusive.
The Tests
- AEA-IgA – Antiendomysial antibody test for gluten or gliadin (called EMA-IgA in USA)
- TtG-IgA – Tissue transglutaminase AUTO antibody test for gluten or gliadin (gliadin is the section of the gluten molecule that causes the problem.
- TtG-IgG – Tissue transglutaminase (necessary to diagnose coeliac disease in IgA deficient individuals; of greater value than IgG Antigliadin antibodies.
- Total serum IgA (Immunoglobulin A) – will identify coeliac disease in symptomatic patients who happen to be IgA deficient. Two of the above tests are IgA based so results of these tests may be falsely low. From this blood test the doctor can decide whether a patient is IgA deficient and can compensate when reading the results of the IgA based tests.
The following tests for wheat or gluten allergy can also be done at the same time if wished. This is to rule out an allergic reaction. It is a simple skin prick test. When testing for coeliac disease the results of these tests will usually be negative.
- IgE for wheat or gluten – called Specific IgE for gluten S79
- RAST test for wheat or gluten
Depending on the results, your doctor may or may not request a small bowel biopsy (a procedure done through the mouth), to remove minute sections of the intestinal wall for examination of possible flattened villi. This procedure does not generally require anaesthetic. It is not painful at all. This is a procedure done in the outpatient’s clinic of a hospital. It is a procedure done to confirm whether the villi in your small bowel are flattened. Villi are microscopic finger-like projections on the walls of the small bowel that absorb nutrients from food.
Some gastroenterologists (e.g. Dr John Wright in Cape Town) can now perform a procedure for photographing the intestinal wall, during which the patient swallows a tiny camera in an endoscopic capsule.
All these tests are covered by all medical aid societies. If you are not on a medical aid, please make enquiries in the gastroenterology department at your nearest government hospital.
Please show this sheet of information to your doctor as he/she may not be aware of some of these tests as they are relatively new in South Africa.
This is a procedure done in the outpatient’s clinic of a hospital. It is a procedure done to confirm whether the villi in your small bowel are flattened. Villi are microscopic finger-like projections on the walls of the small bowel that absorb nutrients from food.
