First described by Samuel Gee in England in 1887 and Christian Herter in the United States, the disease of malnutrition and growth retardation now called Coeliac disease was known as Gee-Herter disease. It is now recognised as an immune-mediated disorder characterised by chronic inflammation of the proximal small bowel, which heals with gluten withdrawal from the diet and returns upon gluten reintroduction. Coeliac disease exhibits geographical variation, with the highest incidence in Western Europe and lower occurrences in Asia and sub-Saharan Africa. Once considered rare (prevalence of 1 in 4,000 to 1 in 5,000 in the 1950s), its true prevalence in Western countries, including Australia, is now estimated to be around 1 in 70. Females are predominantly affected, and serological testing reveals that silent coeliac disease (positive serology and small bowel biopsy without or with minimal symptoms) is about 7 times more common than symptomatic disease. Monozygotic twins have a 70% concordance rate, and first-degree relatives of individuals with coeliac disease have a prevalence of villous atrophy ranging from 4% to 12%. Type I Diabetes and Dermatitis Herpetiformis increase the risk, as do thyroid disease, Down's syndrome, PBC, and IgA deficiency. Gluten encompasses storage proteins from wheat, barley, and rye. Gliadins, the ethanol-soluble component of gluten, are highly immunogenic. In genetically predisposed individuals, an immune response in the mucosal lining of the small intestine leads to mucosal inflammation, increased lymphocytes, crypt hyperplasia, and villous atrophy. Clinical presentations range from no symptoms to IBS-like or classic symptoms such as diarrhea, bloating, and weight loss. Osteoporosis at an early age or unexplained iron deficiency may indicate the disease. Neurological and psychiatric conditions like ataxia, neuropathy, and epilepsy can also be associated. Serological studies for deamidated gliadin, tissue transglutaminase, and endomysium antibodies have sensitivity and specificity above 95%. However, performance may be influenced by IgA deficiency, occurring in 3-5% of coeliac patients, necessitating a diagnostic small intestinal biopsy proximal and distal to the ampulla of Vater. HLA 'gene' screening for DQ-2 and DQ-8 may assist in diagnosing uncertain cases, as a negative result essentially rules out coeliac disease. However, using this test as a screening tool is not recommended, as 20-30% of the normal population carries these HLA antigens without having gluten enteropathy. The lifelong treatment of coeliac disease requires strict adherence to a gluten-free diet. Avoidance of triticale, couscous, spelt, semolina, and cracked wheat is necessary, while rice, corn, buckwheat, tapioca, polenta, and dhal are permitted. Formal dietetic reviews and support groups are strongly advised for patient management. Untreated or inadequately treated coeliac disease carries a 20-fold increased risk of solid malignancies, including oropharyngeal, oesophageal, and intestinal cancers, as well as an 80-fold increased risk of lymphoma. I'm interested in inviting Assoc. Prof. Jason Tye-Din to Everyday Medicine. Jason is an active clinician practicing gastroenterology and a laboratory head in the division of immunology at Melbourne's Walter and Eliza Hall. His research focuses on the inflammatory response to gluten in humans and characterising CD4+T cell antibody responses. He aims to improve clinical pathways for timely and cost-effective diagnosis, monitoring, and management of coeliac disease. Please join me with Jason Tye-Din over the next two episodes. References: Assoc Professor Jason Tye-Din: www.wehi.edu.au Coeliac Society of Australia: www.coeliac.org.au Gastroenterology Society of Australia: www.gesa.org.au The Dietitians Association of Australia: www.data.asn.au Gastronet: www.gastro.net.au