What is Celiac Disease?
(Pronounced: SEE-lee-ack disease)
Celiac disease, also known as celiac sprue or gluten-sensitive enteropathy, is a genetically linked autoimmune disorder that can affect both children and adults. In people with celiac disease, eating certain types of grain-based products sets off an immune mediated response that causes measurable damage to the small intestine. This, in turn, interferes with the small intestine’s ability to absorb nutrients in food, leading to malnutrition and a variety of other complications. The offending amino acid sequences are collectively called “gluten” and are found in wheat, barley, rye, and to a lesser extent, oats* (WBRO). Related proteins are found in triticale, spelt, and Kamut®. Refer to the grains and flours glossary for a more extensive classification of grains.
In people with celiac disease, eating certain types of protein fractions, collectively called gluten, set off an immune mediated response at the site of the epithelial cells. The condition is caused by an abnormal or dysregulated, cellular level immune activity can affect all organs. See Symptoms.
Celiac Disease is an inherited disease. Celiac disease effects those with a genetic predisposition.
- COMMON - Approximately 1 in 141 people haveceliac disease, however, an estimated 80% have yet to be diagnosed based upon the National Health and Nutrition Examination Survey (NHANES) study of the Center for Disease Control. A figure of 1 in 133 came from mainly from Celiac Support Association Chapter sponsored blood screenings in an unprecedented multi-center study of blood samples collected from 13,145 people from February 1996 to May of 2001.
- characterized by (IgA mediated) damage to the mucosal lining of the small intestine known as villous atrophy or enteropathy.
- responsible for the malabsorption of nutrients resulting in malnutrition.
- linked to skin blisters known as dermatitis herpetiformis (DH).
- linked to gluten ataxia.
- not age-dependent. It may become active at any age.
- linked to genetically transmitted histocompatibility cell antigens (HLA DR3-DQ2, DR5/7 DQ2, and DR4-DQ8).
Other genetic links have been identified outside of the HLA area.
Celiac Disease is NOT:
- simply a food allergy (IgE). Wheat allergies are rare among adults. In children, wheat allergies affect .04-.05% of population.
- an idiosyncratic reaction to food proteins (mediated by IgE).
- typified by a rapid histamine-type reaction (such as bronchospasm, urticaria, etc.).
- an intolerance which is a non-immune system response to food.
The Damaging Protein Fractions
The term "gluten" is, in a sense, a generic term for the storage proteins that are found in grains. In reality, each type of protein - glutenin and gliadin in wheat, secalin in rye, hordein in barley, avenin in oats, zein in corn and oryzenin in rice - is slightly different from the others. The "gluten" in wheat, rye, barley, and in a much lower amount, oats, contains particular amino acid sequences that are harmful to persons with celiac disease.
The damaging proteins are particularly rich in proline and glutamine (especially the amino acid sequences which are in the following orders: Pro-Ser-Gln-Gln and Gln-Gln-Gln-Pro). As peptides, some such as 33-MER, cannot be broken down any further in the body. In people with celiac disease, 33-MER stimulates T-cells to produce antibodies. Sequences containing as few as 7 amino acids can be toxic to those with celiac disease. The antibodies, in turn, attack the villi in the small intestine, reducing the surface able to absorb nutrients. The damage may be patchy.
It is important to note that these amino acid or protein sequences are NOT found in the proteins of corn and rice.
The Nature of the Injury
The damage to the small intestine (the jejunum) is very slow to develop and is insidious.
- almost certainly mediated by the immune system.
- associated with ANTIBODIES to glutenin, gliadin, reticulin and/or endomysial (smooth muscle) proteins.
- antibodies may be signals for cell-mediated immunity.
- probably produced by the cellular immune system (T and B cells) - but only when gluten-type prolamins are present.
- reversible, in most cases, to completely or near normal bowel function, if gluten is excluded from the diet.
- normal bowel function, diarrhea, constipation or irritable bowel symptoms may be present.
How Do You Get Celiac Disease?
Celiac disease cannot be "caught," but rather the potential for celiac disease is in the body from birth. Its onset is not confined to a particular age range or gender, although more women are diagnosed than men. It is not known exactly what activates the disease, however three things are required for a person to develop celiac disease:
- A genetic disposition: being born with the necessary genes. The Human Leukocyte Antigen (HLA) genes specifically linked to celiac disease are DR3, DQ2 and DQ8...and others.
- An external trigger: some environmental, emotional or physical event in one’s life. While triggering factors are not fully understood, possibilities include, but are not limited to adding solids to a baby’s diet, going through puberty, enduring a surgery or pregnancy, experiencing a stressful situation, catching a virus, increasing WBRO products in the diet, or developing a bacterial infection to which the immune system responds inappropriately.
- A diet: containing gluten and related prolamins.
- Auto-antigen enzyme, tissue transglutaminase (TG2) also TG4 and TG6.
- Production of proinflammatory cytokines, especially interferon (IFN-γ).
Celiac disease is a life-long disease managed by lifestyle and generally without medication. There is no cure. The only known treatment is strict adherence to a gluten-free lifestyle. The complexity of the disease makes any other safe therapeutic option years away. Oats are not recommended during the first year after diagnosis. Oats can be a choice for many after the first year. There is no way to determine in advance whether or not a person will be able to tolerate uncontaminated oats. Uncontaminated oats and oat products may qualify for the CSA Recognition Seal for Innovative products if absent G12 antibody below 5 ppm of gluten. Call or email the Celiac Support Association home office at 1-877-CSA-4CSA for assistance and guidance on beginning a gluten-free lifestyle.
There is no animal model. The National Health and Nutrition Examination Survey (NHANES) is a program of studies designed to assess the health and nutritional status of adults and children in the United States. The survey is unique in that it combines interviews and physical examinations. Two questions were added to include celiac disease for two years. MCQ082 - Ever been told you have celiac disease? MCQ086 - Are you on a gluten-free diet? NHANES Statement.
- Trier, JS, Celiac Sprue, New England Journal of Medicine, 325:1709-1719, 1991.
- Marsh, MN, Gluten, Major Histocompatibility Complex and the Small Intestine, Gastroenterology, 102:330-354, 1992.
- Marsh, MN, ed Celiac Disease Methods and Protocols, 2000.
- Maki, M and Collin, P, Coeliac Disease, Lancet 349:1755-1759, 1997.
- Sturgess, RP et al, Cereal Chemistry, Molecular Biology and Toxicity in Coeliac Disease, Gut 32:1055-1060, 1991.
- Sturgess, RP et al, Wheat Peptide Challenge in Coeliac Disease, Lancet, 343:759-761, 1994.
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