Celiac Disease

Reviewed on 6/1/2022

Things to Know About Celiac Disease (Celiac Sprue)

Abdominal pain
Celiac disease results from a combination of immunological responses to an environmental factor (gluten) and genetic factors.

  • Celiac sprue, also known as celiac disease, gluten-sensitive enteropathy, and gluten-induced enteropathy, is a chronic disease of the digestive tract that interferes with the digestion and absorption of nutrients from food.
  • People with celiac disease cannot tolerate gluten, a protein commonly found in wheat, rye, barley, and to some degree, oats. When affected individuals ingest foods containing gluten, the lining (mucosa) of the intestine becomes damaged due to the body's immune reaction.
  • Because the lining of the intestine contains essential enzymes for digestion and absorption, its destruction leads to malabsorption, and difficulty in the absorption of food and essential nutrients. As result, celiac disease is often considered a malabsorption disorder.
  • Persons with celiac disease experience improvement in the condition when on a strict, gluten-free diet and relapse when dietary gluten is reintroduced. With treatment, celiac disease is rarely fatal. However, untreated and unrecognized celiac disease may slightly increase the risk of developing intestinal lymphoma, a form of cancer.
  • Celiac disease is a genetic disease; the genes for this condition may be transmitted to some family members and not to others. Sometimes the disease is triggered, or becomes apparent for the first time, after surgery, pregnancy, childbirth, viral infection, or severe emotional stress.
  • Celiac disease is rare in persons with an African American, Caribbean, or Asian background. Females are slightly more affected than males. Although celiac disease can manifest at any age, the detection of this disease usually peaks at 8-12 months and in the third to fourth decade of life.
  • The true prevalence of the celiac disease is not known. The increased awareness and the availability of better diagnostic tests have led to the realization that the disease is relatively common. The highest prevalence is in Western Europe and in places where Europeans emigrated, notably North America and Australia.

Celiac Disease Causes

Celiac disease results from a combination of immunological responses to an environmental factor (gluten) and genetic factors. People need both a genetic predisposition and exposure to gluten in order to develop celiac disease.

Immune mechanisms

  • The interaction of gliadin (a specific gluten present in certain grain products) with the lining of the small intestine is critical in the development of celiac disease. When people with celiac disease eat foods containing gluten, gliadin is identified by the immune system as a threat. As a result, the body produces antibodies called antigliadin antibodies. Antigliadin antibodies are directed against gliadin.
  • Two additional antibodies have been identified in the bloodstream of people with celiac disease. In contrast to antigliadin antibodies, these antibodies target the person's own body and are referred to as autoantibodies (antibodies against our own cells and organs).
    • The first antibody targets endomysium, a small intestinal smooth muscle component.
    • The second antibody targets an enzyme called tissue transglutaminase. The presence of these autoantibodies suggests that autoimmunity plays a role in the disease process of celiac disease.
  • Genetic factors: Genes play an important role in celiac disease. Celiac disease occurs much more frequently in relatives of persons with celiac disease than in the general population.

Celiac Disease Symptoms and Signs

Abdominal pain
The onset of celiac disease symptoms is usually gradual and coincides with the introduction of cereal into the diet. The symptoms usually diminish in adolescence.

Gastrointestinal symptoms in children

Because the celiac disease affects the absorption of nutrients essential for growth, children who are affected may have impaired growth and consequently short stature. Other common signs and symptoms include the following:

The onset of symptoms is usually gradual and coincides with the introduction of cereal into the diet. The symptoms usually diminish in adolescence.

Gastrointestinal symptoms in adults

Celiac disease usually affects adults in the third to fourth decade of life but sometimes later. The signs and symptoms of celiac disease are variable and may include the following:

  • Diarrhea
  • Abdominal discomfort
  • Bloating
  • Steatorrhea, or fatty stools (caused by malabsorption of ingested fat)

Malabsorption of ingested fat results in the delivery of excessive dietary fat to the large bowel. The bacteria in the colon feast on the fats and other undigested and unabsorbed nutrients, generating intestinal gas resulting in bloating and flatulence. In addition, other substances are released, causing secretion of fluid into the intestine and hence diarrhea. Fatigue (tiredness) and weakness can result from the loss of electrolytes, such as potassium and magnesium, due to diarrhea.

Nutrient and vitamin deficiencies

Iron and folic acid are essential for the production of normal red blood cells (erythrocytes). Abnormalities in the absorption of iron or folic acid may result in anemia (low red blood cell count). Vitamin B-12 deficiencies can also contribute to the anemia noticed in affected persons with a mechanism similar to that of iron and folic acid deficiencies.

Vitamin deficiencies may develop when malabsorption is present. Vitamins soluble in fat are commonly malabsorbed. These include vitamins K and D.

  • Vitamin K is essential for the production of clotting proteins. As a result, vitamin K deficiency causes a bleeding tendency among persons with celiac disease.
  • Vitamin D is essential for the absorption of calcium, which is required for appropriate bone growth. As a result, vitamin D deficiency may cause low blood calcium levels (hypocalcemia). This predisposes children with celiac disease to bone disorders such as rickets. Adults with celiac disease have decreased calcium in the bones, which become soft, a condition referred to as osteomalacia, and may develop fractures. Loss of protein and calcium may lead to osteoporosis, in which the bones are porous and brittle.

Nongastrointestinal (extraintestinal) features

Skin disorders can complicate the course of celiac disease. These conditions include dermatitis herpetiformis, an itchy skin condition characterized by a rash or blisters involving the extremities, the trunk, the buttocks, the scalp, and the neck.

Neurologic (nervous system) symptoms include weakness, problems with balance, and sensory changes (for example, sensation of touch and pain).

Hormonal disorders, such as loss of menstruation (amenorrhea) and infertility in women, and impotence and infertility in men, are very uncommon.

When to Seek Medical Care for Celiac Disease

Celiac disease can be a debilitating condition, especially if the diagnosis is not considered early in the course of the disease. As a result, persons with any of the symptoms mentioned above (see Signs and Symptoms) or those with a family history of the disease are encouraged to seek medical advice. Because celiac disease is hereditary, close family members of persons with celiac disease should be tested for the disease.

Females who are pregnant and have worsening anemia should seek medical care. This diagnosis should be considered in females with significant worsening of anemia during pregnancy.

Celiac Disease Diagnosis

The likelihood of celiac disease determines the approach to diagnosis. If a low or moderate suspicion exists that celiac disease is present, a blood test for tissue transglutaminase (tTG) or anti-endomysial antibody is performed. If the likelihood that someone has celiac disease is very high or the blood test result is positive, then biopsies of the small intestinal should be performed.

Genetic testing is only performed in certain circumstances.

Blood tests Blood chemistry, red blood cell, and clotting test results suggest but do not confirm the diagnosis of celiac disease. The same abnormalities may be seen in many other diseases.

  • Electrolyte imbalances, such as low potassium level (hypokalemia), low calcium level (hypocalcemia), and low magnesium level (hypomagnesemia), may be present.
  • Sometimes, malnutrition includes a low albumin level (hypoalbuminemia), a low total protein level (hypoproteinemia), and a low cholesterol level (hypocholesterolemia).
  • Anemia due to deficiency in iron, folate, or vitamin B-12 may be present.
  • A low serum iron level is common.
  • Malabsorption of vitamin K may cause abnormal clotting test results such as a prolonged prothrombin time.

Serologic tests

The best diagnostic tests for celiac disease include measurements of antibody levels to endomysium and to an enzyme called tissue transglutaminase (tTG). The 2 tests are very specific for celiac disease in persons who are untreated.

Measurements of antibodies to gliadin and reticulin (a part of the cell structure) are other diagnostic tests that are less specific for celiac disease.

Small intestine imaging tests

Radiology tests, such as small-bowel barium studies and abdominal/pelvic CT scanning, are usually not helpful in establishing the diagnosis of celiac disease. In video capsule endoscopy, a tiny camera in a capsule films the small intestine as the camera moves through it. However, this study cannot examine the tissue microscopically. These tests should be considered in the evaluation of persons with suspected celiac disease and those who have dramatic weight loss, severe abdominal pain, intestinal bleeding, a significant decrease in albumin levels, and intestinal obstruction. These symptoms may suggest the presence of tumors or ulcers in the small intestine.

Small intestine biopsy

The lining of the small intestine usually consists of fingerlike projections called villi. The villi contain digestive enzymes and provide a large absorptive surface area of the small intestine. In celiac disease, the villi are destroyed because of the inflammatory and autoimmune process. Once the villi are destroyed, nutrients cannot be absorbed. Biopsy samples of the small intestine show mild, moderate, or severe destruction of the villi depending on the severity of the inflammation. Biopsy samples of the small intestine are obtained by introducing a small, flexible endoscope through the mouth, the stomach, and into the small intestine while the patient is sedated.

Celiac Disease Treatment

The treatment for celiac disease is strict avoidance of gluten in the diet.

  • Removal of gluten from the diet is essential. Because a gluten-free diet is a lifetime commitment, is more expensive than a normal diet, and has social implications, it should not be recommended unless the diagnosis is firmly established. Complete avoidance of gluten-containing grain products takes significant effort. Maintaining a strict, gluten-free diet may be relatively difficult because certain products, such as wheat flour, are so common in the Western diet.
  • Improvement in symptoms begins within days of starting the gluten-free diet. Complete healing of the small intestine, meaning the villi are intact and working, usually occurs in 3-6 months, although it may take up to 2 years in older persons.

Because lactose intolerance is common in people with celiac disease, incremental improvements occur when a lactose-free diet is introduced.

Self-Care at Home for Celiac Disease

For the most part, successful control of celiac disease consists of what happens at home to modify diet, and select foods that can be eaten. Many resources are available to assist a person with choosing appropriate foods and modifying recipes to work within his or her diet.

Food labels should be read carefully. Wheat and rye flours, barley, and oats are common ingredients in many products. Many products a person would not suspect contain flour, such as salad dressings. In addition, barley is used in the brewing process of beer. The following substitutions may be tried:

  • Rice flour and bread made with rice flour may be found at local specialty grocery stores.
  • Cornstarch may be substituted for thickening sauces or gravies.
  • Sorghum may also be substituted.

Celiac Disease Medications

  • In a small percentage of persons with celiac disease, the condition fails to respond to a gluten-free diet alone. In some people whose conditions are unresponsive, corticosteroids or lactose restrictions may be helpful.
  • In people whose conditions do not respond well to corticosteroid therapy, other medical conditions should be considered.

Celiac Disease Outlook

  • The celiac disease begins to improve within days of starting a gluten-free diet.
  • Complete healing of the small intestine usually occurs in 3-6 months, although it may take up to 2 years in older persons.

Support Groups and Counseling

Careful and extensive education of a person with celiac disease and their family is often necessary to achieve full compliance. A registered dietitian may be very helpful in providing information and educational resources.

Reviewed on 6/1/2022
References
Medically reviewed by John A. Daller, MD; American Board of Surgery with subspecialty certification in surgical critical care

REFERENCE:

UpToDate. Patient information: Celiac disease in adults (Beyond the Basics).