or '''celiac disease''' is an auto-immune disorder of the
Digestive System that occurs in genetically-predisposed individuals. It is characterised by damage or flattening to all or part of the
Villi lining the
Small Intestine , which interferes with the absoption of nutrients. This damage is caused by eating anything with
Gluten (
Gliadin ), a protein found in
Wheat ,
Rye , and
Barley . A small number of coeliacs (people with coeliac disease) may also react negatively to
Oats , possibly to the protein in them (avenin).
This condition has several other names, including: (with
Ligature ), '''c(o)eliac sprue''', '''non-tropical sprue''', '''gluten enteropathy''', and '''gluten intolerance'''.
The diverse range of coeliac disease symptoms may make it difficult to diagnose. There are over two hundred symptoms that have been identified; not all people have the same symptoms; some people have no symptoms at all; and the symptoms may mimic other diseases. Thorough lists are available
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Gastrointestinal or digestive problems occur in some coeliacs. It used to be thought that all coeliacs had diarrhoea, weight loss, and nutritional deficiencies, but it is now known that only a small percentage have these symptoms. The wide range of digestive symptoms include everything from
Canker Sores to
Diarrhea to
Constipation to
Nausea . Many of the symptoms may mimic other diseases such as
Irritable Bowel Syndrome ,
Reflux , or even
Crohn's Disease and coeliac may be misdiagnosed as any of these. Other symptoms that may occur are bulky, pale, offensive-smelling stools which may float in the toilet bowl, excess
Flatulence , infrequent, minor
Rectal Bleeding , or persistent pain in the abdomen.
Some symptoms appear to be caused because the villi are unable to absorb nutrients. Some examples are
Osteoporosis , damage to teeth enamel,
Anemia , fatigue, rapid or unexplained
Weight Loss ,
Overweight ,
Failure To Thrive or stunted growth in children, etc. Yet other symptoms appear to be emotional, such as
Depression and irritability.
Dermatitis Herpetiformis is an itchy blistering skin disease that occurs in some coeliacs and is considered to be an external manifestation of coeliac disease.
While some untreated coeliacs may be symptom-free, they are still doing damage to their small intestines. Regardless of the presence or absence of symptoms, the disorder is associated with an increased risk of
Osteoporosis , miscarriage, certain types of intestinal cancers, and other auto-immune disorders.
The condition is frequently misdiagnosed or overlooked as it can exhibit multiple symptoms and often the patient or medical staff may not link seemingly unconnected conditions. It is most frequently misdiagnosed when the sufferer complains of
Diarrhea , persistent
Indigestion , a rash or
Irritable Bowel Syndrome .
There are several tests that can be used to assist in diagnosis. The level of symptoms may determine the order of the tests, but all tests must be done while the person is on a gluten containing diet. Antibodies are reduced and intestinal damage begins to heal immediately upon removing all gluten from the diet, so the risk of misdiagnosis is increased if the person is not eating gluten.
The first tests to be run are usually blood tests. These are discussed in detail below. It is possible for a person to have negative results, however, and still have celiac disease. If indicated, either because of positive blood tests, or because test results were not consistent by family history or symptoms are, the next step in diagnosis is through a biopsy. This is considered the "gold standard" test that definitively determines if a person has celiac disease.
An
Upper Endoscopy with
Biopsy of the distal
Duodenum or
Jejunum is performed. It is important for the physician to obtain multiple samples from various places throughout the intestine. However, upper endoscopy carries a risk of false negative results. This is because coeliac disease may or may not damage villi throughout the entire small intestine, and upper endoscopy only examines the upper part of the intestine. In a patient whose intestinal damage is located further down, the biopsy may come back negative.
If the endoscopy is positive, then the diagnosis is confirmed. If the endoscopy is negative, the diagnosis is not necessarily excluded.
For people with Dermatitis Herpetiformis (DH) different tests are used, as not all of them will also have damaged villi, though up to 85% do according to the Celiac Disease Foundation. Aa biopsy of a skin lesion and staining for IgA in the tissues is completed.
Serology has been proposed as a screening measure, because the presence in the blood of
IgA Antibodies reactive against
Gliadin and
Tissue Transglutaminase is indicative of coeliac disease. To show antibodies, the person must be consuming gluten. These tests can be used both to identify coeliac disease and as an annual test to ensure that the celiac is not ingesting gluten.
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A thorough workup includes four tests:
- Anti-tissue transglutaminase Antibody (tTG), IgA. This test is sometimes used alone. If this test is positive it is highly likely that the patient has celiac disease. tTG test is not reliable in children before the age of 2.
- Anti-gliadin antibodies (AGA), IgG and IgA. These tests are often useful when testing young symptomatic children, but they are found in fewer coeliacs than Anti-tTG, and their presence does not automatically indicate coeliac disease because they are found in some other disorders. Some people have an IgA Deficiency . They are unable to mount an IgA response to any antigen and will have False Negative tests for the IgA type celiac tests.
- Anti-endomysial antibodies (EMA), IgA. This test is being replaced by the anti-tTG test because both tests measure the autoantibodies that cause the tissue damage associated with coeliac disease. Many physicians still order this test. This test as tTG test is also not reliable in children before the age of 2.
An older test, the anti-reticulin antibodies (ARA), IgA. IgA Anti-ARA is not ordered as frequently as it once was, because it is less sensitive and less specific than the other tests. It is found in about 60% of people with coeliac disease and 25% of those with dermatitis herpetiformis.
Many doctors do not consider positive blood tests as definitive proof of coeliac disease and require biopsy confirmation. A growing minority consider coeliac disease to be diagnosed where the patient has positive blood tests and shows improved symptoms after the adoption of a gluten-free diet. Because upper endoscopies are expensive and may produce false negative results, this group of doctors considers serology tests and a positive response to eliminating gluten from the diet to be sufficient for diagnosis. The problem with this approach is that patients later commonly want to know if they really have coeliac disease and need to be gluten restricted. A diagnosis with biopsy confirmation at the time of initial diagnosis eliminates this common clinical problem. A small minority of doctors advocate gluten-free diets even for symptom-free patients who have not had an endoscopy but have had a positive blood test, because some confirmed coeliacs are completely symptom-free throughout their lives; in symptom-free patients, the purpose of the diet is to avoid nutritional deficiencies, osteoporosis, and intestinal lymphoma.
Other tests that may assist in the diagnosis are a
Full Blood Count ,
Electrolyte s,
Renal Function and
Liver Enzyme s.
Coagulation testing may be useful to identify deficiency of
Vitamin K , which predisposes patients to
Hemorrhage .
The classic pathology changes of coeliac disease in the small bowel are the following:
The changes classically improve or reverse after
Gluten is removed from the diet.
The cause is
Presently presumed to be:
- Partly a Genetic susceptibility to the illness.
- Together with an environmental agent, probably a Virus or other infection, but stress and pregnancy have also been invoked as possible triggers.
- It is associated with other Autoimmune Disease s; these diseases are also probably a combination of susceptibility and infection.
- Possible exposure to gluten as a young baby before the Gut Barrier has developed fully (though this is still subject to further research).
Autoantigens are probably of major importance in the pathogenesis of coeliac disease (transglutaminase), a trait it shares with many other autoimmune diseases; thyroiditis: thyroglobulin, thyroid peroxidase; multiple sclerosis: myelic basic protein, etc. To some extent infectious agents may increase the risk of certain autoimmune diseases (e.g.
Coxsackie B in type 1 diabetes). There are few proofs of infections triggering coeliac disease, however.
Some researchers have suggested that smoking is protective against coeliac disease. Results on this topic are however inconsistent, and smoking cannot be recommended as a means to avoid developing coeliac disease.
