| Abdomen |
Often called the belly. the section of the body between the chest (thorax) and pelvis. Contains many parts of the digestive tract (e.g. stomach, small intestine, and large bowel [also known as the colon]). |
| Biopsy |
The removal of a tissue sample for the purpose of examination. In coeliac disease, the tissue samples obtained from the duodenal biopsy are examined under a microscope (i.e. histological examination) for evidence of coeliac disease (e.g. villous atrophy). |
| Brain-gut axis (BGA) |
The bi-directional relationship between the central nervous system (i.e.brain and spinal cord) and the gastrointestinal tract (i.e. the enteric nervous system). The electrochemical process in the brain can influence the gut (e.g. passage of food, intestinal permeability), which may cause gastrointestinal symptoms (e.g. diarrhoea, constipation). Conversely, information from the gut (e.g. inflammation, microbial signals) can affect our thoughts, feelings, and behaviour. |
| Coeliac disease |
A chronic condition immune-mediated condition affecting the small bowel that emerges when a genetically susceptible individual ingests gluten. |
| Coeliac serology |
The array of blood tests that are used in the screening and diagnosis of coeliac disease. |
| Cross contamination |
When a gluten-free food/ingredient becomes unsafe to eat due to contact with a gluten-containing food/ingredient. |
| Dapsone |
An antibiotic often used to treat the skin condition dermatitis herpetiformis. |
| Deamidated gliadin peptide (DGP IgA/IgG) |
A test of DGP antibodies that are produced because of the abnormal immune reaction to gluten in individuals with coeliac disease. May be used to screen for coeliac disease in those with an IgA deficiency. |
| Dermatitis herpetiformis |
A skin condition characterised by rash of red itchy bumps that affects a subset of individuals with coeliac disease. |
| Duodenum |
The first section of small bowel, immediately after the stomach. To confirm a diagnosis of coeliac disease, the physician will conduct a duodenal biopsy. |
| Endoscope |
A long, flexible tube-like device with a video camera on the end. An endoscope is used to examine the digestive tract for signs of disease (i.e., gastroscopy). |
| False negative |
Test results that erroneously indicates a condition/illness is not present, when in fact it is. |
| False positive |
Test results that erroneously indicates a condition/illness is present, when in fact it is not. |
| Gastrointestinal |
Relating to the digestive tract, that is, the organs that make up the passage beginning at the mouth and ending at the anus. |
| Gastroscopy |
A procedure wherein an endoscope is inserted through the mouth to examine the upper GI tract. In coeliac disease, the endoscope traverses the stomach and into the first section of the small bowel, the duodenum, where a biopsy is taken. |
| Gluten |
A composite of water insoluble proteins found in wheat, barley, and rye. |
| Gluten-free |
Containing no detectable gluten, or containing gluten at a level that is below the threshold set by regulatory bodies (e.g., in Europe and the USA, gluten-free means a ratio of 20 parts per million [ppm] of gluten or less) |
| HLA |
Human leukocyte antigen (HLA) testing. Used in coeliac disease screening to investigate potential genetic susceptibility towards coeliac disease. |
| HLA-DQ2 and/or HLA-DQ8 |
Human leukocyte antigen (HLA) genetic variations. Almost every person with coeliac disease has one or both variants. Absence of these genetic variants typically rules out the possibility of coeliac disease. |
| IgA Endomysial antibody (EMA) |
A highly specific antibody test for coeliac disease –virtually everyone with a coeliac-positive EMA result has coeliac disease. Less commonly used than tTG-IgA, DGP IgA/IgG, and total serum IgA test. |
| Mucosal healing |
Healing of the lining of the small bowel. Those with coeliac disease can expect the small bowel to heal with time and strict adherence to the gluten-free diet . |
| Non-coeliac gluten sensitivity |
A term used to describe a condition wherein symptoms related to gluten exposure are observed in individuals in which coeliac disease has been excluded as a potential cause. |
| Small bowel/small intestine |
The section of the digestive tract between the stomach and the large bowel (aka colon). The small bowel is the primary location of disease activity in coeliac disease. |
| Tissue transglutaminase IgA antibodies (tTG-IgA) |
A measure of the level of tTG-IgA antibodies that are produced in individuals with coeliac disease after they have consumed gluten. It is used in the screening of coeliac disease, typically conducted in combination with either the deamidated gliadin peptide (DGP IgA/IgG) test or the total serum IgA test. |
| Total serum IgA |
A test of IgA antibody deficiency that is often administered in combination with the tTgA-IgA test. IgA deficiency can result in a false negative on the tTgA-IgA test (i.e., someone with coeliac testing negative for it on the tTgA). |
| Villi |
The millions of finger-like projections that line the inside of the small bowel. |
| Villous atrophy |
The flattening of the villi within the small bowel. In coeliac disease, the villi become damaged due to the body’s abnormal immune reaction to gluten. |
