Coeliac disease is caused by a reaction to gliadin, a prolamin (gluten protein) found in wheat, and similar proteins found in the crops of the tribe Triticeae (which includes other common grains such as barley and rye). Upon exposure to gliadin, and specifically to three peptides found in prolamins, the enzyme tissue transglutaminase modifies the protein, and the immune system cross-reacts with the small-bowel tissue, causing an inflammatory reaction. That leads to a truncating of the villi lining the small intestine (called villous atrophy).
The inability to absorb carbohydrates and fats may cause weight loss (or failure to thrive/stunted growth in children) and fatigue or lack of energy. Anaemia may develop in several ways: iron malabsorption may cause iron deficiency anaemia, and folic acid and vitamin B12 malabsorption may give rise to megaloblastic anaemia.
An upper endoscopy with biopsy of the duodenum (beyond the duodenal bulb) or jejunum is performed. It is important for the physician to obtain multiple samples (four to eight) from the duodenum. Not all areas may be equally affected; if biopsies are taken from healthy bowel tissue, the result would be a false negative. Most people with coeliac disease have a small intestine that appears normal on endoscopy; however, five concurrent endoscopic findings have been associated with a high specificity for coeliac disease: scalloping of the small bowel folds (pictured), paucity in the folds, a mosaic pattern to the mucosa (described as a "cracked-mud" appearance), prominence of the submucosa blood vessels, and a nodular pattern to the mucosa
Germany in 2002. Initially, 4000 of the total 12475 residents were randomly selected by the staff of the municipal registry office from the roster of inhabitants. Out of these 4000 persons, 107 were excluded because their address was unknown or they had not given their informed consent. A total of 2445 individuals finally participated in the study, corresponding to a participation rate of 62.8%. Following exclusion of subjects less than 18 years and subjects with incomplete laboratory results, 2157 subjects were finally included in the present