This glossary is a list of common terms related to celiac disease, non-celiac gluten sensitivity and other gluten-related disorders.
This glossary has been developed through a joint program of the Gluten-Related Disorders Collaborative, a group composed of the leading advocacy groups in the US working in the field of celiac disease and non-celiac gluten sensitivity: American Celiac Disease Alliance, Celiac Disease Foundation, Celiac Sprue Association, Gluten Intolerance Group and the National Foundation for Celiac Awareness.
The glossary is based on a consensus document published by a group of celiac disease experts from around the world. (Read more about the Oslo definitions here.) The purpose of this glossary is to further the use of that lexicon to provide greater uniformity across patient-related organizations.
For a list of terms that are no longer recommended for use, click here.
Celiac disease: Celiac disease is a chronic small intestinal immune-mediated enteropathy precipitated by exposure to dietary gluten in genetically predisposed individuals. Celiac disease is triggered by the ingestion of gluten (definition below), the protein component of wheat, rye, barley, but not oats. Such exposure results in a variable degree of intestinal damage. To confirm a diagnosis of celiac disease, biopsies of the duodenum must be taken when patients are on a gluten-containing diet. It is generally agreed that four to six biopsies are necessary for diagnosis, including from the duodenal bulb.
Asymptomatic celiac disease: Asymptomatic celiac disease is not accompanied by symptoms even in response to direct questioning at initial diagnosis. Individuals with asymptomatic celiac disease do not manifest any symptoms commonly associated with celiac disease and have no symptoms that respond to gluten withdrawal, even in response to direct questioning. These patients often suffer from decreased quality of life.
At risk family members: (formerly Genetically at risk of celiac disease) - Family members of patients with celiac disease that test positive for HLA DQ2 and/or DQ8 are genetically at risk of celiac disease. (Note: The Oslo definitions refer to this term as "genetically at risk of celiac disease.")
Blood tests for celiac disease (serology): Blood tests for celiac disease are used to determine whether at risk individuals have elevated levels of certain autoantibodies—proteins that react against the body's own cells or tissues—in their blood. The initial tests will screen for the presence of anti-tissue transglutaminase antibodies (tTGA) or anti-endomysium antibodies (EMA). The results of these tests will determine whether additional testing is necessary.
For these tests to be reliable, a patient must be consuming foods that contain wheat, rye, or barley, e.g. gluten-containing grains.
Classical celiac disease: Classical celiac disease presents with signs and symptoms of malabsorption. Diarrhea, steatorrhea, weight loss or growth failure is required. Examples of classical celiac disease are patients with diarrhea and weight loss but also patients with weight loss and anemia.
Dermatitis herpetiformis is the skin manifestation of untreated or undiagnosed celiac disease. It is characterized by blistering, intensely itchy skin. Individuals with dermatitis herpetiformis need to follow a gluten-free diet.
Gliadin-specific antibodies: These are AGAs (anti-gliadin antibodies) of IgA (Immunoglobulin A) and IgG (Immunoglobulin G) subclass recognizing the gliadin moiety of wheat. Antibodies recognizing native gluten are now rarely used for diagnostic purposes because they lack general specificity. Antibodies recognizing DGP (deamidated gliadin peptide) demonstrate high specificity and sensitivity. They can also be used for measurement of gluten in foodstuffs. Use of the term gliadin-specific antibodies generally refers to antibodies directed against the gliadin moiety of wheat prolamins. The following four aspects of these antibodies are relevant to the spectrum of gluten-induced disease.
Diagnostic value - After introduction in the 1980s, IgA antibodies against wheat gliadin (AGAs) served as the best serological test for celiac disease for some years. However, the low positive predictive value meant that this test has since been abandoned for the investigation of celiac disease, except for in children younger than 18 months, in whom IgA AGA seems to have high sensitivity. Recently, assays for IgA and IgG antibodies against DGP have been introduced and perform similarly to TTG-based tests.
Disorders beyond the classical enteropathy - AGAs are also relevant to gluten-induced disorders beyond the classical enteropathy. The most well known example is gluten ataxia. Patients with this disorder may have celiac disease or only elevated levels of IgA or IgG AGAs (see gluten ataxia).
Increased gut permeability - Elevated levels of AGAs have also been used for the investigation of possible increased gut permeability, but this use in clinical practice lacks a strong scientific background.
Gluten: Gluten is the common name for the proteins in specific grains that are harmful to persons with celiac disease and gluten-related disorders. These proteins are found in ALL forms of wheat (including durum, semolina, spelt, kamut, einkorn and faro) and related grains rye, barley and triticale.
While science has demonstrated that gluten is poorly digested in all populations, it is critical for those with celiac disease and other gluten-related disorders to embrace a gluten-free diet as a medical necessity and the only treatment for these conditions.
Gluten ataxia: Gluten ataxia is one of a number of neurological symptoms of celiac disease and is often characterized by one or more of the following: poor coordination, imbalance, lack of control of bodily movements.
Gluten-related disorders: The term is used to describe all conditions resulting from the ingestion of gluten including: gluten ataxia, dermatitis herpetiformis, non-coeliac gluten sensitivity and celiac disease.
Non-celiac gluten sensitivity: Non-celiac gluten sensitivity is a condition that occurs in individuals who are unable to tolerate gluten and experience symptoms similar to those associated with celiac disease. Diagnostic tests for celiac disease or food allergies are negative in such individuals. May also be referred to as "gluten sensitivity" upon second and further references.
Non-classical celiac disease: Non-classical celiac disease presents without signs and symptoms of malabsorption. In non-classical celiac disease the patient does not suffer from malabsorption (e.g., a patient with constipation and abdominal pain but no malabsorption). Patients with monosymptomatic disease (other than diarrhea or steatorrhea) usually have non-classical celiac disease.
Oats (A Special Caution): Oats in their natural form do not contain the gluten protein. However, fields where oats are grown and mills that produce and store oats may also grow and manufacture wheat, barley or rye resulting in cross-contamination. Current research strongly suggests that the majority of patients with celiac disease can tolerate oats in their pure, uncontaminated form. A very small percentage of individuals with celiac disease do react to pure, uncontaminated oats. Although the cause for this reaction is not completely understood, some literature suggests that a protein in oats can trigger a response similar to gluten.
Individuals who would like to add oats to their diet should do so under the guidance of their dietitian or physician. Oat intake should be limited to the equivalent of one-half cup of rolled oats per day. Any oats and products containing oats that are eaten must be labeled gluten-free. Individuals who develop any new symptoms after adding oats to their diet should bring this to the attention of their dietitian or physician.
Pediatric classical celiac disease: Pediatric classical celiac disease is the pediatric equivalent of classical celiac disease. These children are often characterized by failure to thrive, diarrhea, muscle wasting, poor appetite and abdominal distension. Many children with classical celiac disease and malabsorption also show signs of emotional distress (‘change of mood’) and lethargy.
Subclinical celiac disease: Subclinical celiac disease is below the threshold of clinical detection.
Symptomatic celiac disease: Symptomatic celiac disease is characterized by clinically evident gastrointestinal and/or extraintestinal symptoms attributable to gluten intake. The clinical manifestations of celiac disease vary from none (asymptomatic celiac disease) to a wide spectrum of symptoms which may include: ataxia, depression, migraine headaches, short stature (in children), diarrhea, infertility, constipation, iron-deficiency anemia, fatigue, joint pain, canker sores in the mouth, or seizures.
Potential celiac disease: Potential celiac disease relates to people with a normal small intestinal mucosa who are at increased risk of developing celiac disease as indicated by positive celiac disease serology. (Read more about the biopsy process to confirm a celiac disease diagnosis: Endoscopy)
*NFCA has elected to use these terms. They are not part of the glossary created by the Gluten-Related Disorders Collaborative.