In the United Kingdom, the National Institute for Health and Clinical Excellence (NICE) does not (as of 2015) recommend the use of HLA typing to rule out coeliac disease outside of a specialist setting, for example, in children who are not having a biopsy, or in patients who already have limited gluten ingestion and opt not to have a gluten challenge. Endoscopy
An upper endoscopy with biopsy of the duodenum (beyond the duodenal bulb) or jejunum is performed 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. Even in the same bioptic fragment, different degrees of
damage may be present.Most people with coeliac disease have a small intestine that appears to be normal on endoscopy before the biopsies are examined. However, five findings have been associated with 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.European guidelines suggest that in children and adolescents with symptoms compatible with coeliac disease, the diagnosis can be made without the need for intestinal biopsy if anti-tTG antibodies titres are very high (10 times the upper limit of normal).Until the 1970s, biopsies were obtained using metal capsules attached to a suction device. The capsule was swallowed and allowed to pass into the small intestine.
A small proportion have abnormal coagulation because of vitamin K deficiency and are at a slight risk of abnormal bleeding. Miscellaneous
Coeliac disease has been linked with many conditions. In many cases, it is unclear whether the gluten-induced bowel disease is a causative factor or whether these conditions share a common predisposition. IgA deficiency is present in 2.3% of people with coeliac disease, and is itself associated with a tenfold increased risk of coeliac disease. Other features of this condition are an increased risk of infections and autoimmune disease. Dermatitis herpetiformis, an itchy cutaneous condition that has been linked to a transglutaminase enzyme in the skin, features small-bowel changes identical to those in coeliac disease and may respond to gluten withdrawal even if no gastrointestinal symptoms are present. Growth failure and/or pubertal delay in later childhood can occur even without obvious bowel symptoms or severe malnutrition. Evaluation of growth failure often includes coeliac screening. Pregnancy complications can occur if coeliac disease is pre-existing or later acquired, with significant outcomes including miscarriage, intrauterine growth restriction, low birthweight and preterm birth. Hyposplenism (a small and underactive spleen) occurs in about a third of cases and may predispose to infection given the role of the spleen in protecting against harmful bacteria. Abnormal liver function tests (randomly detected on blood tests) may be seen.Coeliac disease is associated with several other medical conditions, many of which are autoimmune disorders: diabetes mellitus type 1, hypothyroidism, primary biliary cholangitis, microscopic colitis, gluten ataxia, psoriasis, vitiligo, autoimmune hepatitis, primary sclerosing cholangitis, and more.