Coeliac Disease (CD) or Gluten-sensitive Enteropathy is a chronic life-long inflammatory disease of the small bowel intestinal lining. It is often misdiagnosed as Irritable Bowel Syndrome and affects about 1% of children in the UK, according to the British Medical Journal.
by Dr Adrian Morris
Coeliac Disease is triggered by a delayed onset allergic reaction to a grain protein called gluten in the normal diet. Gluten is a protein found mainly in Wheat and to a lesser extent in Rye and Barley. Hence the alternative name for the condition of Gluten-sensitive Enteropathy. People with stable Coeliac Disease will tolerate Oats in the diet.
Coeliac Disease (CD) is an inherited disease of the intestinal immune system and affects both men and women. It is highly prevalent in the United Kingdom, affecting 1 in 300 or more people but can be quite difficult to reliably detect. Most CD is finally diagnosed in adulthood usually in the 30-45 year age group. As a result, many cases go undiscovered and are often falsely diagnosed as Irritable Bowel Syndrome (IBS). In fact only about one third of cases are ever diagnosed as CD and appropriately treated with a gluten-free diet. Untreated CD is associated with long-term health risks such as osteoporosis, diabetes, anaemia, infertility and gastrointestinal malignancy.
Samuel Gee first described the condition in 1888. The classical symptoms are malabsorption of food and chronic diarrhoea associated with anaemia, rickets, failure to grow, abdominal bloating, offensive bulky stools, a blistering rash on the buttocks and mouth ulcers. Small children usually become symptomatic when they are weaned off milk onto solids. They present with weight loss, refusal to feed, irritability, abdominal swelling and diarrhoea. However in adults, the disease often presents in an atypical form and may be missed – especially with non-specific symptoms such as fatigue, mouth ulcers, skin rashes, vague abdominal pains, intermittent diarrhoea and chronic anaemia.
A rash called Dermatitis Herpetiformis (also called Duhring’s disease) may occasionally occur in Coeliac Disease. It is an intensely itchy rash with symmetrical fine blisters which typically appear on the back, elbows or scalp, almost all people with Dermatitis Herpetiformis have Coeliac Disease. Treatment includes avoidance of Gluten and a medication called Dapsone.
Certain groups of people are at greater risk for developing Coeliac Disease. It is commoner in individuals from families that already have the condition (being linked to the HLA DQ2 gene). Coeliac Disease is more likely to occur in people with Diabetes on Insulin, Downs Syndrome, Sarcoidosis, Infertility, IgA antibody deficiency and certain autoimmune diseases such as Thyroid disease, Rheumatoid Arthritis, Chronic active Hepatitis, Addisons disease and Sjorgens syndrome of dry eyes and mouth.
Coeliac Disease testing
A recently developed blood test has revolutionised the diagnosis of Coeliac Disease. Up until this point, CD could only be detected after years of severe symptoms and an intestinal biopsy. This resulted in milder cases of Coeliac Disease remaining undiagnosed or being misdiagnosed. The Coeliac Screening blood test measures antibodies in the blood to Gluten or Gliaden in the diet and the damaged Endomysial muscle of the bowel. The Anti-Gliaden (AGA) Antibodies disappear on a Gluten-free diet and are a good indicator of Gluten avoidance and disease resolution. The Endomysial (EMA) Antibodies persist in all people with untreated and treated Coeliac Disease and this was the initial screening test. However, these tests are not 100% accurate in diagnosing CD. 2% of sufferers with IgA deficiency will have a negative EMA test while some people with a positive EMA test may have no CD symptoms at all. Over the last decade, measuring Tissue Transglutaminase antibodies (to the endomysial antigen) has become the test of choice to compliment the Endomysial antibody test. The person being tested must have been on a Gluten-containing diet for at least 6 weeks otherwise one can get a false-negative results if the have excluded gluten from their diet before taking the blood test.
We do therefore recommend that people with a positive EMA screening test still have an intestinal biopsy to confirm the presence of CD before embarking on a lifelong diet of wheat and gluten avoidance. The intestinal biopsy can now readily be done at the time of oesophago-gastrointestinal endoscopy (OGD). The small intestinal biopsy must be done after a wheat-based diet for accurate diagnosis. A biopsy specimen taken on a wheat-free diet might show a completely normal intestinal lining. Anti-Reticulin (ARA) Antibodies may also be measured in CD but most UK pathology laboratories tend to test for the Tissue Transglutaminase or Anti-Gliaden IgA and the Anti-Endomysial (EMA) antibodies. Home stool testing kits for Gluten Intolerance are unreliable and not recommended for diagnosis.
New genetic screening for Coeliac Disease has become available which actually measures HLA proteins on our blood cells or skin cells from our mouth. We each inherit two sets of HLA DQ genetic material, one copy from each of our parents and it has been found that 98% of Coeliacs have a combination of DQ2 / DQ8. This has made screening for Coeliac Disease easier than performing an intestinal biopsy in those people who have a negative Coeliac screening blood test (Tissue Transglutaminase) but benefit from a gluten free diet. This gene test will conclusively exclude the possibility of Coeliac Disease if negative for DQ2/DQ8. It does not confirm Coeliac Disease exists, as a third of the general (healthy) population will carry the gene, but have no Coeliac Disease.
Complications of Coeliac Disease
Coeliac sufferers absorb fewer nutrients from their diet and so may develop nutritional deficiencies. 50% will develop osteoporosis or fractures from calcium deficiency. There is a two-fold increased risk of cancers of the mouth, throat and gullet as well as intestinal lymphomas and carcinomas. They develop chronic anaemia due to not absorbing iron and folic acid from the damaged bowel. There is a strong link with insulin dependant Diabetes through the HLA DR3 gene. People with Downs Syndrome have a 43 times greater chance of developing Coeliac Disease but will often develop a milder form of the disease.
Coeliac Disease treatment
The only effective treatment of CD is strict lifelong complete avoidance of Gluten found in cereals such as Wheat, Rye and Barley (many tolerate Oats). It is completely safe to eat Maize, Corn or Rice. The Coeliac Society of Great Britain is a wonderful support-organisation that provides extensive information on gluten-free diets and foods. Gluten-free flour may be prescribed on the NHS. Unfortunately, CD patients are not entitled to free prescriptions. With the increased potential for developing osteoporosis, sufferers should be closely monitored and all menopausal women and men over 55 years of age who suffer with CD should have bone density (DEXA) scanning.
Gluten Intolerance or Coeliac Disease should not be overlooked
Coeliac Disease is significantly under-diagnosed in the UK and most cases are detected later in their 40’s due to the ill-defined symptoms that occur. The Tissue Transglutaminase screening test is an important development and all patients with vague intestinal symptoms, particularly patients with unexplained diarrhoea, anaemia, mouth ulcers, rashes and chronic fatigue should be tested. It would also be prudent to screen patients with diabetes, thyroid disease, Downs syndrome and osteoporosis for CD.
For more information visit www.coeliac.0rg.uk
Conditions confused with Coeliac Disease:
Non-Coeliac Gluten Intolerance (NCGI) is a clinical condition where people with milder symptoms of fatigue (brain fog), depression and stomach upsets (diarrhoea, constipation, bloating) respond to the withdrawal of Wheat and Gluten from their diet. When wheat is reintroduced their symptoms recur, but on testing Tissue Transglutaminase antibodies and intestinal biopsy all appears normal. This is termed Non Coeliac Gluten Intolerance (NCGI) or Non-Coeliac Wheat Sensitivity (NCWS) and generally responds well to a Gluten reduced diet but has none of the Coeliac complications.
Crohns Disease, an autoimmune inflammatory disease of the small bowel affects people in the 14 to 24 year age groups. Their symptoms are often more severe than in Coeliac Disease. They develop chronic diarrhoea, fever, severe cramps, weight loss, bowel obstruction, vomiting and anorexia. They may have blood in the stools if the lower bowel is affected (20%) of cases. Crohns is also associated with arthritis, anal abscesses, skin lesions, eye problems and mouth ulcers. Blood tests characteristically show a raised ESR, raised neutrophil blood cell count and raised CRP. Faecal Calprotectin will be raised in active Inflammatory Bowel Disease. The Barium Enema x-ray has a diagnostic appearance. Diet and Gluten avoidance play no role in Crohns Disease and treatment is with cortisone and Salazopyrine. Another inflammatory disease of the lower bowel presenting with more bloody diarrhoea but similar to Crohns Disease is Ulcerative Colitis
Irritable Bowel Syndrome (IBS) is the “disease of negatives”. It affects all ages, predominantly young women and is not life-threatening. IBS is diagnosed when there are symptoms of diarrhoea, constipation and abdominal bloating or pain but all tests for other bowel diseases are negative. Those with symptoms who have normal blood tests, normal stool tests, a normal barium enema and a normal colonoscopy end up being diagnosed with IBS. Very often food intolerances to cow’s milk, fruit and wheat plays a role and they respond well to a low fermentable carbohydrate diet (FODMAP), while stress may exacerbate the condition. Probiotics acidophilus supplementation may be of benefit.
Two sub-types of IBS occur:
Spastic Colon: Sufferers have mainly left-sided abdominal pain, recurrent constipation and symptom relief on opening the bowels.
Functional diarrhoea: Sufferers have discomfort and bloating associated with frequent diarrhoeal stools in the morning. These are usually watery or mucous laden and can be rather explosive.
We see many patients with presumed wheat intolerance, but who test negative for gluten intolerance and wheat allergy despite debilitating symptoms such as bloating, abdominal cramps and diarrhoea with constipation. Despite these negative tests, they respond favorably to a wheat exclusion diet.
These symptoms may be attributed to fructans (sugars derived from fruit juice such as sucrose and fructose) which are either added or naturally occur in cereals (wheat, oats, rye and barley), legumes, onions, leeks, asparagus and artichokes. Fructose is also found naturally in Rosacea family fruits such as apple, cherry, apricot, plum and pear juices and may be added as Sorbitol sweetener found in diabetic foods. With excessive intake, these short chain carbohydrate Fructans, may pass unabsorbed into the lower bowel where they ferment under influence of bowel microorganisms producing unpleasant gases (hydrogen, methane, carbon dioxide and hydrogen sulphide). These gases then lead to the typical bloating and flatulent symptoms similar to those experienced by individuals with lactose intolerance to dairy products. Fermentable dietary oligosaccharides, disaccharides, monosaccharides and polyols or FODMAPs exacerbate Irritable Bowel Syndrome (IBS) symptoms as well. Corn, rice, spelt and gluten-free products tend not to contain fructans or FODMAPs