What is Celiac Disease?

(En Español)

Celiac disease has been known by many different names in the medical literature over the years, including gluten-sensitive enteropathy and celiac sprue (to differentiate it from tropical sprue). CELIAC DISEASE can be defined as a permanent intolerance to the gliadin fraction of wheat protein and related alcohol-soluble proteins (called prolamines) found in rye and barley. CELIAC DISEASE occurs in genetically susceptible individuals who eat these proteins, leading to an autoimmune disease, where the body’s immune system starts attacking normal tissue. This condition continues as long as these food products are in the diet.

The resulting inflammation and atrophy of the intestinal villi (small, finger-like projections in the small intestine) results in the malabsorption of critical vitamins, minerals, and calories. Signs and symptoms of the disease classically include diarrhea, short stature, iron-deficiency anemia and lactose intolerance. However, many patients will also present with “non-classical” symptoms, such as abdominal pain, “irritable bowel”, and osteoporosis. Patients may also be screened for celiac disease because of the presence of another autoimmune disease, such as type I diabetes or thyroid disease, or a family history of celiac disease, without having any obvious symptoms. Serum antibodies can be utilized to screen for celiac disease. However, the key to confirming the diagnosis remains a small intestinal biopsy, and the patient’s subsequent clinical response to a gluten-free diet. Clinicians in the United States must maintain a high index of suspicion for this disease, as it is significantly under-diagnosed in this country.

What is a wheat allergy?

People can also have other medical problems, besides celiac disease, when they eat wheat and related proteins. Wheat allergy is one of the top 8 food allergies in the United States. Allergic reactions after eating wheat may include reactions in the skin, mouth, lungs, and even the GI tract. Symptoms of wheat allergy can include rash, wheezing, lip swelling, abdominal pain and diarrhea. The branch of the immune system activated in allergic reactions is different from the branch thought to be responsible for the autoimmune reactions of celiac disease.

What is gluten intolerance?

People can also experience ‘intolerance’ to gluten. Food intolerances are not thought to be immune mediated. GI symptoms with wheat or gluten intolerance may include gassiness, abdominal pain, abdominal distension, and diarrhea. These symptoms are usually transient, and are thought NOT cause permanent damage.

Patients with lactose intolerance, where the lactose sugar in diary products is not digested well, may also experience gassiness, abdominal pain, abdominal distension, and diarrhea. Like gluten or wheat intolerance, these symptoms will pass once the lactose is out of the person’s system, and will not cause permanent damage.

Why is it important to know if you have celiac disease, versus wheat allergy or gluten intolerance?

Celiac disease, wheat allergy and gluten-intolerance are treated similarly, in that patients with these conditions must remove wheat from their diet. It is important to note, however, that there is a difference between these three medical problems. Celiac disease is an autoimmune condition, where the body’s immune system starts attacking normal tissue, such as intestinal tissue, in response to eating gluten. Because of this, people with celiac disease are at risk for malabsorption of food, which cause nutritional deficiencies and may result in conditions such as iron deficiency anemia, osteopenia, and osteoporosis.  Persons with a wheat allergy or gluten-intolerance usually do not have severe intestinal damage, and therefore are not at risk for these nutritional deficiencies.  They also are not at increased risk of developing other autoimmune conditions.

Unlike a food allergy or food intolerance, celiac disease is an inherited condition.  This means family members may have it, too.  For this reason, if someone in your family is diagnosed, it is recommended that first degree relatives (parents, children, siblings) are screened as well.  Finally, celiac disease involves the activation of a particular type of white blood cell, the T lymphocyte, as well as other parts of the immune system, which may increase the risk of developing GI cancers, in particular lymphomas, in persons with celiac disease.  Since food allergies and intolerances do not involve this particular immune system pathway, these patients are not at increased risk for these cancers.

While celiac disease, wheat allergy, and gluten-intolerance may be treated with similar diets, they are not the same conditions. Due to the genetic component, and risk of nutritional deficiencies, other autoimmune diseases, and GI cancers, it is very important for a person to be properly diagnosed.