What is Coeliac Disease?
Coeliac Disease (CD), also known as Gluten Intolerance, is a condition of the small intestine that affects around 1 in 300 people and while it can affect anyone at any age, a definite risk factor to developing CD is a history of the condition in your family. Gluten, a substance found in wheat, barley and ry, reacts with the small intestines causing damage by activating the immune system to attack the delicate bowel lining, which is responsile for absorbing nutrients and vitamins.
What are the symptoms?
Coeliac Disease has many and varied symptoms and can include, although is not exclusive to;
- Weight loss
- Tiredness
- Vomiting
- Lethargy
- Breathlessness
- Abdominal Discomfort
- Anaemia
- Mouth Ulcers
- Diarrhoea
Why test for Coeliac?
Because of the broard range of symptoms CD presents it is difficult it is difficult to diagnose. If undiagnosed, CD patients who continue to ingest gluten will have an increased risk of developing gastrointestinal tumours, so early detection of CD is very important.
How does the test work?
Testing is simple and involves either screening the patient’s blood for Anti-gliadin (AGA) or tTG-IgA Antibodies, with a follow up intestinal biopsy in positive cases to confirm the presence of the villous changes.
Anti-gliadin test.
Gliadin is a major protein found in the gluten fraction of wheat. The antibodies found in blood are of the IgG and IgA class. While IgA is very specific for CD, it is not present in 100% of cases. Gliadin IgG antibodies are found in 95% of coeliac patients, provided the patient is not on a gluten free diet, but they are also present in some other diseases. For this reason both classes of antibodies are measured. The test uses the accurate ELISA technology.
Transglutaminase IgA test (tTG-IgA)
This is a new immunological marker for the identification of patients with CD. tTG appears to be more specific than Gliadin IgA and appears to remain in the blood longer than gliadin IgG/ IgA, even weeks after a patient has stopped taking gluten.
tTG IgA antibodies appear to preferentially recognise the calcium-ion activated form of transglutaminase. Calcium is in fact a required co-factor for TGA’s enzymatic activity. External studies have shown that the CNS Transglutaminase IgA test results show 99% – 100% correlation with the “Gold Standard” endomysial antibodies tests. A positive tTG IgA result ic compelling evidence of Coeliac disease, provided the patient is not already on a gluten free diet.
Some Celiac patients suffer from IgA deficiency and in these cases, tTG-IgA will be falsely negative. In such cases, a gliadin test may prove more useful.
Sample required and test turnround.
Both tests require just a pin-prick blood sample. Results are available within 10 working days.