Celiac Disease

Celiac disease is the most commonly identified autoimmune malabsorption disease in which the villae and microvillae of the small intestine are damaged, interfering with absorption of nutrients from food.The prevalence of celiac disease in the United States has been estimated to be as high as one in 133 individuals. At the same time, only one in 4,700 individuals have been diagnosed with celiac disease.

Other Names

• Celiac sprue
• Coeliac disease
• Nontropical sprue
• Gluten-sensitive enteropathy

Signs and Symptoms

Celiac disease affects people in various ways. Symptoms may occur in the digestive system, or in other parts of the body. For example, one person might have diarrhea and abdominal pain, while another person may be irritable or depressed. In fact, in children, irritability is one of the most common symptoms.

Symptoms of celiac disease may include one or more of the following:

• excessive gas
• recurring abdominal bloating and/or pain
• chronic diarrhea
• constipation
• pale, foul-smelling, or fatty stool
• weight loss
• fatigue
• unexplained anemia (a low count of red blood cells causing fatigue)
• bone or joint pain
• osteoporosis or osteopenia
• behavioral changes
• tingling and numbness in the legs (from nerve damage)
• muscle cramps
• missed menstrual periods (often because of excessive weight loss)
• infertility, recurrent miscarriage
• delayed growth
• failure to thrive in infants and children
• pale sores inside the mouth, called aphthous ulcers
• tooth discoloration or loss of enamel
• itchy skin rash called dermatitis herpetiformis
• seizure disorder
• hypoproteinemia

A person with celiac disease may have little or no symptoms. People without symptoms are still at risk for the complications of celiac disease, including malnutrition and small bowel lymphoma. The longer a person goes undiagnosed and untreated, the greater the chance of developing malnutrition and other complications. Anemia, delayed growth, and weight loss are signs of malnutrition: The body is just not getting enough nutrients. Malnutrition is a serious problem for children because they need adequate nutrition to develop properly.

Researchers are studying the reasons celiac disease affects people differently. Some people develop symptoms as children, others as adults. Some people with celiac disease may not have symptoms, while others may not know their symptoms are from celiac disease. The undamaged part of the small intestine may be able to absorb enough nutrients to prevent symptoms.

Causes

Diagram of gastrointestinal tract with shading of the small intestine. Source: National Digestive Diseases Information Clearinghouse.

Close-up illustration of a small section of the small intestine with flap cut away to reveal inner wall. An inset shows the microscopic fingerlike structures, called villi and microvillae, on the inner surface of the small intestine. Source: National Digestive Diseases Information Clearinghouse.

People who have celiac disease cannot tolerate a protein called gluten, found in wheat, rye, and barley. Gluten is found mainly in foods, but may also be found in everyday products, such as stamp and envelope adhesive, medicines, and vitamins.

When people with celiac disease eat foods or use products containing gluten, their immune system attacks the small intestine. The tiny, fingerlike protrusions (called "villi") that line the small intestine are damaged or destroyed. The villi normally allow nutrients from food to be absorbed into the bloodstream. Without healthy villi, a person becomes malnourished, regardless of the quantity of food eaten.

Because the body's own immune system causes the damage, celiac disease is considered an autoimmune disorder. However, it is also classified as a disease of malabsorption because nutrients are not absorbed.

Celiac disease is a genetic disease, meaning it runs in families. Sometimes the disease is triggered—or becomes active for the first time—after surgery, pregnancy, childbirth, viral infection, or severe emotional stress.

Diagnosis

Recognizing celiac disease can be difficult because some of its symptoms are similar to those of other diseases. In fact, sometimes celiac disease is confused with irritable bowel syndrome, iron-deficiency anemia caused by menstrual blood loss, Crohn's disease, diverticulitis, intestinal infections, and chronic fatigue syndrome. As a result, celiac disease is commonly underdiagnosed or misdiagnosed.

Recently, researchers discovered that people with celiac disease have higher than normal levels of certain autoantibodies in their blood. Antibodies are protective proteins produced by the immune system in response to substances that the body perceives to be threatening. Autoantibodies are proteins that react against the body's own molecules or tissues. To diagnose celiac disease, physicians will usually test blood to measure levels of the following:

• Immunoglobulin A (IgA)(An IgA deficiency can mask or affect accuracy

of the antibody tests as below)

• anti-tissue transglutaminase (tTGA)
• IgA anti-endomysium antibodies (AEA)
• HLA-DQ2 and HLA-DQ8 gene tests which can be used to exclude celiac disease in doubtful cases

IgA antiendomysial antibodies can detect celiac disease with a sensitivity and specificity of 90% and 99% according to a systematic review. The systematic review estimates that the prevalence of celiac disease in primary care patients with gastrointestinal symptoms to be about 3%. This results in a positive predictive value of and a negative predictive value of 74% and negative predictive value of 3% (click here to recalculate for different prevalences of celiac disease).^[1]The review found that IgA antitissue transglutaminase antibodies performs similarly, but is an easier test to perform.^[1]

Before being tested, one should continue to eat a regular diet that includes foods with gluten, such as breads and pastas. If a person stops eating foods with gluten before being tested, the results may be negative for celiac disease even if celiac disease is actually present (a false negative result).

If the tests and symptoms suggest celiac disease, the doctor will perform a small bowel biopsy. During the biopsy, the doctor removes a tiny piece of tissue from the small intestine to check for damage to the villi. To obtain the tissue sample, the doctor eases a long, thin tube called an endoscope through the mouth and stomach into the small intestine. Using instruments passed through the endoscope, the doctor then takes the sample.

Screening

Screening for celiac disease involves testing for the presence of antibodies in the blood in people without symptoms. Americans are not routinely screened for celiac disease. Testing for celiac-related antibodies in children less than five years old may not be reliable. However, since celiac disease is hereditary, family members, particularly first-degree relatives—meaning parents, siblings, or children of people who have been diagnosed—may wish to be tested for the disease. About 5%-15% of an affected person's first-degree relatives will also have the disease. About 4.5% of people with type 1 diabetes will have biopsy-confirmed celiac disease,^[2] and 5%–10% of people with Down's syndrome will be diagnosed with celiac disease.

Treatment

The only treatment for celiac disease is to follow a gluten-free diet. When a person is first diagnosed with celiac disease, the doctor usually will ask the person to work with a dietitian on a gluten-free diet plan. A dietitian is a health care professional who specializes in food and nutrition. Someone with celiac disease can learn from a dietitian how to read ingredient lists and identify foods that contain gluten in order to make informed decisions at the grocery store and while eating out.

For most people, following this diet will stop symptoms, heal existing intestinal damage, and prevent further damage.^[3] Improvements begin within days of starting the diet. The small intestine is usually completely healed in three to six months in children and younger adults and within two years for older adults. Healed means a person now has villi that can absorb nutrients from food into the bloodstream.

In order to stay well, people with celiac disease must avoid gluten for the rest of their lives. Eating any gluten, no matter how small an amount, can damage the small intestine. The damage will occur in anyone with the disease, including people without noticeable symptoms. Depending on a person's age at diagnosis, some problems will not improve, such as delayed growth and tooth discoloration.

Some people with celiac disease show no improvement on the gluten-free diet. This condition is called unresponsive celiac disease. The most common reason for poor response is that small amounts of gluten are still present in the diet. Advice from a dietitian who is skilled in educating patients about the gluten-free diet is essential to achieve the best results.

Rarely, the intestinal injury will continue despite a strictly gluten-free diet. People in this situation have severely damaged intestines that cannot heal. Because their intestines are not absorbing enough nutrients, they may need to receive nutrients directly into their bloodstream through a vein (intravenously). People with this condition need to be evaluated for complications of the disease. Researchers are now evaluating drug treatments for unresponsive celiac disease.

The gluten-free diet

A gluten-free diet means not eating foods that contain wheat (including spelt, triticale, and kamut), rye, and barley. The foods and products made from these grains are also not allowed. In other words, a person with celiac disease should not eat most grains, pasta, and cereal, and should avoid many processed foods. Despite these restrictions, people with celiac disease can eat a well-balanced diet with a variety of foods, including gluten-free bread and pasta. For example, people with celiac disease can use potato, rice, soy, amaranth, quinoa, buckwheat, or bean flour instead of wheat flour. They can buy gluten-free bread, pasta, and other products from stores that carry these foods, or order products from special food companies. Gluten-free products are increasingly available from regular stores.

Checking labels for “gluten-free” is important since many corn and rice products are produced in factories that also manufacture wheat products. Hidden sources of gluten include additives such as modified food starch, preservatives, and stabilizers. Wheat and wheat products are often used as thickeners, stabilizers, and texture enhancers in foods.

“Plain” meat, fish, rice, fruits, and vegetables do not contain gluten, so people with celiac disease can eat as much of these foods as they like. Recommending that people with celiac disease avoid oats is controversial because some people have been able to eat oats without having symptoms. Oats can, however, be contaminated with wheat, rye, or barley products.^[4]

Gluten is also used in some medications. One should check with the pharmacist to learn whether medications used contain gluten. Since gluten is also sometimes used as an additive in unexpected products, it is important to read all labels. If the ingredients are not listed on the product label, the manufacturer of the product should provide the list upon request.

Some examples

In 2006, the American Dietetic Association updated its recommendations for a gluten-free diet. The following list is based on the 2006 recommendations. This list is not complete, so people with celiac disease should discuss gluten-free food choices with a dietitian or physician who specializes in celiac disease. People with celiac disease should always read food ingredient lists carefully to make sure that the food does not contain gluten. ^[5]

Allowed foods

Foods to avoid

• Wheat
  • Including einkorn, emmer, spelt, kamut
  • Wheat starch, wheat bran, wheat germ, cracked wheat, hydrolyzed wheat protein
• Barley
• Rye
• Triticale (a cross between wheat and rye)

• Other wheat products
  • Bromated flour
  • Durum flour
  • Enriched flour
  • Farina
  • Graham flour
  • Phosphated flour
  • Plain flour
  • Self-rising flour
  • Semolina
  • White flour

Processed foods that may contain wheat, barley, or rye

Most of these foods can be found gluten-free. When in doubt, check with the food manufacturer.

• Bouillon cubes
• Brown rice syrup
• Chips/potato chips
• Candy
• Cold cuts, hot dogs, salami, sausage
• Communion wafers
• French fries
• Gravy
• Imitation fish
• Matzoh
• Rice mixes
• Sauces
• Seasoned tortilla chips
• Self-basting turkey
• Soups
• Soy sauce
• Vegetables in sauce
• Herbal or nutritional supplements
• Over the counter medications

Living with Celiac Disease

Lifestyle changes

The gluten-free diet can be difficult to follow. It requires a completely new approach to eating that affects a person's entire life. Newly diagnosed people and their families may find support groups to be particularly helpful as they learn to adjust to a new way of life. People with celiac disease have to be extremely careful about what they buy for lunch at school or work, what they purchase at the grocery store, what they eat at restaurants or parties, and what they grab for a snack. Eating out can be a challenge. If a person with celiac disease is in doubt about a menu item, he or she can ask the waiter or chef about ingredients and preparation. Gluten-free menus are available at some restaurants.See the list of restaurants on the Gluten Intolerance Group page. See external links below also for tasty gluten-free recipes.

Chances of Developing Celiac Disease

Risk factors

The length of time a person is breastfed, the age a person started eating gluten-containing foods, and the amount of gluten-containing foods one eats are three factors thought to play a role in when and how celiac disease appears. A thorough review of several studies shows, for example, that the longer a person was breastfed, the later the symptoms of celiac disease appear and the more uncommon the symptoms. In addition, being breastfed at the time of introduction of gluten-containing foods decreases the risk of developing celiac disease.^[6]

Genetics

There is a strong genetic predisposition to celiac disease. The genetic markers, known as Histocompatibility Antigens, HLA-DQ2 and HLA-DQ8 are most strongly associated with celiac disease.^[7]

Heredity

People with family members with celiac disease are at higher risk of developing celiac disease themselves. One study found that asymptomatic siblings of people with celiac disease have a 24–48-fold increased risk of having evidence of celiac disease on blood tests.^[8]

Related Problems

Complications

Damage to the small intestine and the resulting nutrient absorption problems put a person with celiac disease at risk for malnutrition, anemia, and several other diseases and health problems.

• Lymphoma and adenocarcinoma are cancers that can develop in the intestine. An important cause of mortality in patients with celiac disease is non-Hodgkin's lymphoma.
• Osteoporosis is a condition in which the bones become weak, brittle, and prone to breaking. Poor calcium absorption contributes to osteoporosis. It can be the only sign of celiac disease.^[9]
• Miscarriage and congenital malformation of the baby, such as neural tube defects, are risks for pregnant women with untreated celiac disease because of nutrient absorption problems, especially of the vitamin folate.
• Short stature refers to being significantly under the average height. Short stature results when childhood celiac disease prevents nutrient absorption during the years when nutrition is critical to a child's normal growth and development. Children who are diagnosed and treated before their growth stops may have a catch-up period.

Related disorders

People with celiac disease tend to have other autoimmune diseases. The connection between celiac disease and these diseases may be genetic. These diseases include:

• Thyroid disease such as Hashimoto's thyroiditis
• [[Systemic lupus erythematosus]]
• Type 1 diabetes
• Liver disease
• Collagen vascular disease
• Rheumatoid arthritis
• Sjogren syndrome

Other conditions associated with celiac disease include:

• Dermatitis herpetiformis
• Down syndrome. One study found that 12% of adults with Down syndrome had celiac disease.^[10]
• Infertility. Early studies have reported an incidence of celiac disease in infertile women of 4%-8%, though a recent study in the United States did not find an increased incidence.^[11]

Dermatitis herpetiformis

Dermatitis herpetiformis(DH) is a severe, itchy, blistering skin manifestation of celiac disease. Not all people with celiac disease develop dermatitis herpetiformis. The rash usually occurs on the elbows, knees, and buttocks. Unlike other forms of celiac disease, the range of intestinal abnormalities in DH is highly variable, from minimal to severe. Only about 20% of people with DH have intestinal symptoms of celiac disease.

To diagnose DH, the doctor will test the person's blood for autoantibodies related to celiac disease and will biopsy the person's skin. If the antibody tests are positive and the skin biopsy has the typical findings of DH, patients do not need to have an intestinal biopsy. Both the skin disease and the intestinal disease respond to a gluten-free diet and recur if gluten is added back into the diet. In addition, the rash symptoms can be controlled with medications such as dapsone (4-,4-diamino-diphenylsuphone). However, dapsone does not treat the intestinal condition. Maintaining a gluten-free diet is also an important part of treating DH.

Research

The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) conducts and supports research on celiac disease. NIDDK-supported researchers are studying the genetic and environmental causes of celiac disease. In addition, researchers are studying the substances found in gluten that are believed to be responsible for destruction of the particular immune system function found in celiac disease. They are engineering enzymes designed to destroy these immunotoxic substances. Researchers are also developing educational materials to raise awareness among healthcare providers. The hope is that increased understanding and awareness will lead to earlier diagnosis and treatment of celiac disease.

History

Statistics

In one town in Italy that was thought to have a low incidence of celiac disease, 1 in 100 people were found to have the disorder on screening.^[12] A recent study in Finland of 2815 individuals aged 52 to 74 years found an overall incidence of biopsy-proven celiac disease of 2.45%. Sixty patients were diagnosed, and 20 of them had no symptoms.^[13]

Until recently, celiac disease was thought to be uncommon in the United States. However, studies have shown that celiac disease is very common. According to the NIH, 0.5%–1% of the US population, or 3 million people, have celiac disease.^[7]

Celiac disease could be underdiagnosed in the United States for a number of reasons including:

• Celiac symptoms can be attributed to other problems.
• Many doctors and health care providers are not knowledgeable about the disease,not having had exposure during their training.
• Only a small number of U.S. laboratories are experienced and skilled in testing for celiac disease.

More research is needed to learn the true prevalence of celiac disease among Americans.

Public Health

The celiac disease awareness campaign

To meet the need for comprehensive and current information about celiac disease, the National Digestive Diseases Information Clearinghouse (NDDIC), a service of the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), launched the Celiac Disease Awareness Campaign. The Awareness Campaign is the result of the combined ideas and efforts of the professional and voluntary organizations that focus on celiac disease, along with the NIDDK, the National Institutes of Health, and the Centers for Disease Control and Prevention.

References

1. ↑ ^{1.0 1.1} van der Windt, Daniëlle A W M et. al. "Diagnostic testing for celiac disease among patients with abdominal symptoms: a systematic review." JAMA : the journal of the American Medical Association 303 (2010): 1738-46 - Abstract
2. ↑ Holmes GK. Screening for coeliac disease in type 1 diabetes. Arch Dis Child. 2002 Dec;87(6):495-8. Abstract | Full Text
3. ↑ Usai P, Manca R, Cuomo R, Lai MA, Boi MF. Effect of gluten-free diet and co-morbidity of irritable bowel syndrome-type symptoms on health-related quality of life in adult coeliac patients. Dig Liver Dis. 2007 Sep;39(9):824-8. Epub 2007 Jul 23. Abstract
4. ↑ Thompson T. Oats and the gluten-free diet. J Am Diet Assoc. 2003 Mar;103(3):376-9. Abstract
5. ↑ Thompson T. Celiac Disease Nutrition Guide, 2nd ed. Chicago: American Dietetic Association; 2006.
6. ↑ Akobeng AK, Ramanan AV, Buchan I, Heller RF. Effect of breast feeding on risk of coeliac disease: a systematic review and meta-analysis of observational studies. Arch Dis Child. 2006 Jan;91(1):39-43. Epub 2005 Nov 15. Abstract.
7. ↑ ^{7.0 7.1} NIH Consensus Development Conference on Celiac Disease. NIH Consens State Sci Statements. 2004 Jun 28-30;21(1):1-23.
8. ↑ Bardella MT, Elli L, Velio P, Fredella C, Prampolini L, Cesana B. Silent celiac disease is frequent in the siblings of newly diagnosed celiac patients. Digestion. 2007;75(4):182-7. Epub 2007 Sep 11. Abstract
9. ↑ Stazi AV, Trecca A, Trinti B. Osteoporosis in celiac disease and in endocrine and reproductive disorders. World J Gastroenterol. 2008 Jan 28;14(4):498-505. Abstract
10. ↑ Wallace RA. Clinical audit of gastrointestinal conditions occurring among adults with Down syndrome attending a specialist clinic. J Intellect Dev Disabil. 2007 Mar;32(1):45-50. Abstract
11. ↑ Jackson JE, Rosen M, McLean T, Moro J, Croughan M, Cedars MI. Prevalence of celiac disease in a cohort of women with unexplained infertility. Fertil Steril. 2008 Apr;89(4):1002-4. Epub 2007 Jul 26. Abstract
12. ↑ Menardo G, Brizzolara R, Bonassi S, Marchetti A, Dante GL, Pistone C, et al. Population screening for coeliac disease in a low prevalence area in Italy. Scand J Gastroenterol. 2006 Dec;41(12):1414-20. Abstract
13. ↑ Vilppula A, Collin P, Mäki M, et al. Undetected coeliac disease in the elderly: A biopsy-proven population-based study. Dig Liver Dis. 2008 May 6 [Epub ahead of print]. Abstract

External Links

American Dietetic Association

Celiac Disease Foundation

Celiac Sprue Association

Gluten Intolerance Group of North America

National Foundation for Celiac Awareness

North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition (NASPGHAN)

Celiac Chicks

Gluten free on a shoestring