What is Celiac Disease?
(Pronounced: SEE-lee-ack disease)
Celiac disease (CD), 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 CD, eating certain types of grain-based products sets off an immune 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 CD, eating certain types of protein fractions, collectively called gluten, set off an immune mediated response at the site of the epithelial cells. This abnormal, cellular level immune activity can affect all organs.
Celiac Disease is: an inherited disease. Celiac disease effects those with a genetic predisposition.
- COMMON - Approximately 1 in 133 people have CD, however, most have yet to be diagnosed. This number is based upon a milestone multi-center study of blood samples collected from 13,145 people from February 1996 to May of 2001. This means that there were over 2.1 million undiagnosed people with celiac disease in the United States in 2001.
- characterized by (IgA mediated) damage to the mucosal lining of the small intestine known as villous atrophy.
- 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.
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, 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 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 their ability to absorb nutrients.
It is important to note that these sequences are NOT found in the proteins of corn and rice.
The Nature of the Injury
The damage to the small intestine (the jejunum) caused by this disease is very slow to develop and is insidious. It is:
- almost certainly mediated by the immune system.
- associated with ANTIBODIES to glutenin, gliadin, reticulin and/or endomysial (smooth muscle) proteins.
- probably not directly caused by the antibodies, though they 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 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 CD may be 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 CD:
- 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.
- A 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 WBRO, or any of their derivatives.
Celiac disease is life-long and currently incurable. The only known treatment at this time is strict adherence to a gluten-free lifestyle, free of WBRO. Oats are not a risk free choice for those with celiac disease and not reccommended during the first year. There is no way to determine in advance whether or not a person will be able to tolerate uncontaminated oats. Contact CSA for assistance and guidance on beginning a gluten-free lifestyle.
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 new questions added to include celiac disease. 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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