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.
Cause
Coeliac disease is caused by an inflammatory reaction to gliadins and glutenins (gluten proteins) found in wheat and to similar proteins found in the crops of the tribe Triticeae (which includes other common grains such as barley and rye) and to the tribe Aveneae (oats). Wheat subspecies (such as spelt, durum, and Kamut) and wheat hybrids (such as triticale) also cause symptoms of coeliac disease.A small number of people with coeliac disease react to oats. Oat toxicity in coeliac people depends on the oat cultivar consumed because the prolamin genes, protein amino acid sequences, and the immunoreactivities of toxic prolamins are different in different oat varieties. Also, oats are frequently cross-contaminated with other grains containing gluten. The term "pure oats" refers to oats uncontaminated with other gluten-containing cereals. The long-term effects of pure oat consumption are still unclear, and further studies identifying the cultivars used are needed before making final recommendations on their inclusion in a gluten-free diet. Coeliac people who choose to consume oats need a more rigorous lifelong follow-up, possibly including periodic intestinal biopsies. Other grains
Other cereals such as corn, millet, sorghum, teff, rice, and wild rice are safe for people with coeliac disease to consume, as well as noncereals such as amaranth, quinoa, and buckwheat. Noncereal carbohydrate-rich foods such as potatoes and bananas do not contain gluten and do not trigger symptoms. Risk modifiers
There are various theories as to what determines whether a genetically susceptible individual will go on to develop coeliac disease.