The Coeliac Screen (tTG) uses proven ELISA-based technology to detect circulating IgA and IgG antibodies raised against tissue Transglutaminase (tTG).
Frequently Asked Questions
- What is coeliac disease?
- Coeliac disease (CD) is an autoimmune disorder that damages the small intestine and interferes with the absorption of essential nutrients from food. Individuals who have CD cannot tolerate gluten – a protein found in wheat, rye, and barley, which may also be found in everyday products such as medicines, vitamins and lip balms.
- What causes coeliac disease?
- When individuals with CD eat foods containing gluten (or use products containing gluten), this triggers a severe autoimmune response which damages the tiny, finger-like protrusions (villi) lining the small intestine. Villi enable nutrients to be absorbed through the walls of the small intestine into the bloodstream. Without healthy villi, a person rapidly becomes malnourished, regardless of how much food is consumed.
- What are the symptoms of coeliac disease?
- • Diarrhoea, excessive wind and/or constipation • Persistent gastrointestinal symptoms, including, stomach pain, cramping, bloating, nausea and vomiting • Iron, vitamin B12 or folic acid deficiency • Anaemia • Tiredness • Sudden or unexpected weight loss (but not in all cases) • Mouth ulcers • Alopecia • Skin rash • Neurological problems including ataxia (loss of coordination, poor balance) and peripheral neuropathy (numbness and tingling in the hands and feet) • Repeated miscarriages • Tooth enamel problems • Depression • Liver abnormalities
- Why test for coeliac disease?
- The National Institute for Care and Health Excellence (NICE) has advised that people with close relatives (for example father, mother, son, daughter, siblings) are at increased risk of CD and so should be considered for screening. If you suffer from any of the symptoms of CD (described above), already have an autoimmune disease and/or have a family history of autoimmune disease, then you should discuss your concerns with your GP, who may advise that you undertake a blood test.
- What should be considered before taking the test?
- The NICE guidelines from May 2009 state that gluten should be included in the diet in at least one meal daily for a minimum of 6 weeks before testing, which is what we also advise. However, we also recommend that if you start having severe symptoms when reintroducing gluten that you should stop. It is possible however, that symptoms may be due to being intolerant to other proteins in wheat in which case you may like to experiment with foods including rye or barley in your diet. If symptoms subside this will ensure that you are still eating gluten and so are able to perform the test.
- How does the test work?
- The CNS Coeliac Screen (tTG) test is an ELISA-based method for the detection of circulating IgA and IgG antibodies raised against tissue Transglutaminase (tTG).
- What will the test results tell me?
- tTG IgA Studies have shown that IgA antibodies to tTG – an enzyme present in the connective tissue of the gut – are also strongly associated with the presence of CD. tTG IgA antibodies are highly sensitive (95% -100%) and specific (90%-97%) for CD. tTG IgG Patients with CD can exhibit IgA-deficiency. In such cases, the tTG IgA test will produce a negative result. A tTG IgG test is then recommended to prevent false negative results being obtained (NICE clinical guideline 86). A follow up intestinal biopsy should be conducted in positive cases, to confirm the presence of damaged villi.
- What can be done if I have coeliac disease?
- Once CD has been diagnosed, it is recommended that a gluten-free diet is followed for life. It is also essential to ensure a nutritionally adequate diet, to compensate for the malabsorption of nutrients that may have occurred. The Coeliac Society publishes a list of gluten-free manufactured products in a booklet which is updated every year. Often many coeliac sufferers are found to be anaemic. This is usually due to iron deficiency due to malabsorption. Folic acid or vitamin B12 may also be deficient. An iron supplement maybe prescribed until the digestive system recovers and can absorb iron again. To ensure a good intake of iron, pulses, lentils, nuts and green vegetables should be included in the daily diet . Tea should be avoided with meals as it inhibits iron absorption, but fruit juice will aid absorption (due to vitamin C content). For further details see www.coeliac.co.uk Vegetarians and vegans should be aware that some gluten-free flours are low in protein, due to the removal of gluten, however, specially manufactured, prescribed gluten-free flours often have milk protein added. Please check ingredients labels carefully. Other proteins suitable for vegetarians/ vegans can be obtained from nuts & seeds, pulses, non-gluten containing cereals, soya products, milk, cheese and free range eggs. The Vegetarian Society can provide further information: www.vegsoc.org