How Is Celiac Disease Diagnosed?

Gluten Sensitive Enteropathy

Celiac disease is not a true food allergy.

What Is Celiac Disease?

Celiac disease is an autoimmune disease of the small intestine caused by intolerance to gluten, a protein found in various cereal grains such as wheat, rye and barley. Symptoms of celiac disease include diarrhea, abdominal pain, weight loss, and trouble absorbing nutrients from the intestines (malabsorption). It affects approximately 1 in 100 people, and Caucasians are even more commonly affected.

The most common ages people are diagnosed is infancy (at about 1 year of age) and adults in their 30s and 40s. Women are affected nearly twice as often as men.

Celiac disease is a genetic disorder that runs in families. A person with celiac disease has white blood cells that react to gluten proteins in an abnormal way. This reaction caused inflammation in the intestinal tract, which leads to the symptoms of celiac disease. Since the intestines have a difficult time absorbing nutrients, a person with celiac disease is also at risk for nutritional deficiencies, including vitamin deficiencies, anemia and osteoporosis.

How Is Celiac Disease Diagnosed?

Celiac disease is typically diagnosed with the use of blood tests as well as an intestinal biopsy performed via endoscopy. Antibodies against various proteins in the body can be detected in the blood of people with celiac disease. One of these proteins, called tissue transglutaminase (tTG) is involved in the processing of gluten proteins.

In a person with celiac disease, the immune system sees tTG linked to gluten as abnormal, and creates antibodies against this structure. Other antibodies in people with celiac disease include endomysial antibody, as well as antibodies against a component of gluten, called gliadin.

While the detection of certain antibodies is highly suggestive of the diagnosis of celiac disease, an intestinal biopsy is required to confirm the diagnosis.

The biopsy shows loss of the normal architecture of the small intestine, with the presence of white blood cells in the lining of the intestine. While there is no finding on intestinal biopsy that is specific to celiac disease, an abnormal biopsy is required to make the diagnosis of celiac disease.

Is Celiac Disease Caused By An Allergic Reaction?

Celiac disease is not caused by an allergic reaction; therefore allergy testing is not useful for making the diagnosis. There is no allergic antibody directed against gluten proteins in people with celiac disease. Rather, the antibodies involved are of the IgG and IgA type, and are mostly directed against the bodies own antigens bound to gluten proteins.

How Is Celiac Disease Treated?

The main treatment of celiac disease is the avoidance of gluten proteins in the diet. A gluten-free diet is difficult and expensive to follow, although given the increased public awareness of celiac disease, is becoming easier to do so. Most cereal grains need to be avoided, although rice and corn are gluten-free, as are oats (although oats may be contaminated with gluten from other cereal grains).

Following a gluten-free diet usually results in improvement of the symptoms of celiac disease, as well as resolution of the intestinal biopsy abnormalities, and normalization of the autoantibody levels in the blood.

Gluten-free diet also can prevent the development of other diseases associated with celiac disease (see below).

Learn how to follow a gluten-free diet.

What Other Diseases are Associated with Celiac Disease?

A number of different autoimmune diseases can occur in people with celiac disease, although following a gluten-free diet seems to decrease the chance that these will occur. These autoimmune diseases include thyroid disease (such as Hashimoto’s thyroiditis), liver disease (autoimmune hepatitis and primary biliary cirrhosis), juvenile rheumatoid arthritis, myasthenia gravis and type 1 diabetes mellitus.

It also appears that these autoimmune diseases also occur at a higher rate in immediate family members with celiac disease.

In addition to autoimmune diseases, people with celiac disease are also at an increased risk of non-Hodgkin lymphoma, as well as a variety of neurologic conditions including epilepsy, dementia and migraine headaches. Dermatitis herpetiformis, an itchy, blistering skin rash most often occurring on the elbows, knees, lower back and scalp, also occurs in people with celiac disease – and can be the only symptoms that a person may experience. Luckily, following a gluten-free diet either decreases or eliminates the chance that these associated diseases will occur in people with celiac disease.

Lastly, many people meeting the diagnostic criteria for irritable bowel syndrome (IBS) are four times more likely to have celiac disease than people without IBS. Whether there is an association between celiac disease and IBS, or if the two diseases have such similar symptoms, and therefore the diagnosis of one disease is confused for the other disease, is unknown.


Freeman HJ, Chopra A, Clandinin MT, Thomson ABR. Recent Advances in Celiac Disease. World J Gastroenterol. 2011;17(18):2259-2272.

Rubio-Tapia A, Murray JA. Celiac Disease. Curr Opin Gastroenterol. 2010;26:116-122.

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