WHAT IS CELIAC DISEASE?— Celiac disease (also called gluten sensitive enteropathy ("enter-AH-pathy"), celiac sprue, and nontropical sprue) was first described by Samuel Gee in 1888 in a report entitled "On the Coeliac Affection," although a similar description of a chronic, intestinal disorder by Aretaeus from Cappadochia (now Turkey) reaches as far back as the 2nd century AD. It is a condition in which the lining of the small intestine is abnormal but improves once gluten (a protein contained in wheat, rye, barley, and a multitude of prepared foods) is eliminated from the diet. People with celiac disease have an abnormal immune system reaction against gluten, the consequences of which cause damage to the lining of the small intestine. Celiac disease can occur in people of any age and affects both genders.
The small intestine is responsible for absorbing food and nutrients. Thus, damage to the lining, such as occurs in celiac disease, results in impaired absorption of nutrients, a condition referred to as "malabsorption." The associated signs and symptoms vary from person to person. In the mildest form, which doctors sometimes refer to as "subclinical," patients may have no symptoms whatsoever. However, such patients may have evidence of malabsorption on laboratory testing, such as a low blood count from decreased absorption of iron. Others may have diarrhea, weight loss, abdominal discomfort, excessive gas, osteoporosis, and other signs and symptoms due to deficiencies of specific vitamins and nutrients. Still others may have signs or symptoms of a number of conditions that are more common in patients with celiac disease, including:
WHAT CAUSES IT? — As mentioned above, celiac disease is caused by an abnormal immune system response to dietary gluten. Why some people develop the abnormal response and others do not is incompletely understood. Genetic factors are clearly important since celiac disease occurs primarily in whites of northern European ancestry. There is a strong link between inheritance of specific genes that regulate the immune response (HLA DQ2) and risk for celiac disease. The exact mechanisms that underlie the abnormal immune system response are gradually being uncovered.
HOW IS IT DIAGNOSED? — Celiac disease may be suspected in patients who have clinical or laboratory abnormalities suggesting the diagnosis. Blood tests detecting certain antibodies produced by patients with celiac disease can strongly support the diagnosis. The most accurate of these tests are for:
These tests are positive in more than 90 percent of people with untreated celiac disease, and are rarely positive in those without celiac disease.
Confirmation of the diagnosis requires examination of a sample of the lining of the small intestine under the microscope. This is usually accomplished during an upper endoscopy, which is a very safe test that involves swallowing a small flexible instrument that can allow your doctor to examine the upper part of the gastrointestinal system. A sample of the small intestine (biopsy) can be obtained during the examination. The biopsy is not painful.
The most characteristic finding of the small intestinal lining under the microscope is flattening of the finger- or frond-like structures, which are called "villi" (show histology). Villi are essential for the normal absorption of nutrients. Once gluten is removed from the diet, the villi grow back. Some doctors recommend documenting the regrowth by repeating a biopsy some months after gluten has been eliminated from the diet. In some cases, if the diagnosis is still in doubt after a period of treatment with a gluten free diet it may be necessary to reintroduce gluten and demonstrate that the flattening returns. A decline in the levels of endomysial antibody in the blood are expected once on a gluten-free diet.
Patients with celiac disease should be tested for nutritional deficiencies that may result from malabsorption. Common tests include a blood count to detect anemia from iron, folic acid, or vitamin B12 deficiency, and tests to detect calcium or vitamin K deficiency. Many doctors recommend that patients with celiac disease undergo specific testing for bone loss. One method involves using a DEXA (dual energy x-ray absorptiometry) scan, a painless imaging test that determines the density of bone. Those who have developed significant bone loss may require specific treatment. Vaccination against pneumonia (Pneumovax) has also been recommended.
HOW IS IT TREATED? — The cornerstone of treating celiac disease is to completely eliminate gluten from the diet. Patients who are malnourished because of the disease may also need certain nutrient supplements. As mentioned above, those who have developed significant bone loss may require specific treatment.
Maintaining a gluten-free diet can be a difficult task requiring major lifestyle adjustments since gluten is contained in the most commonly consumed grains in the Western world (wheat, rye, and barley) and is included as an additive in multiple prepared foods. Thus, it is usually best to consult with a nutritionist who can provide detailed guidance and written information on permissible foods. In addition, a number of helpful resources are available that can provide dietary advice and support. ().
Fortunately, life on a gluten free-diet has become increasingly easier with the gaining popularity of gluten-free foods. Excellent gluten-free substitutes for traditional gluten-containing foods are now widely available.
DO I HAVE TO BE STRICT ABOUT ELIMINATING GLUTEN? — People with celiac disease should be very strict about avoiding gluten since even small amounts can cause the disease. Oats do not appear to be harmful but should be avoided unless special steps have been taken during their production to avoid contamination by the other harmful cereals.
People who had no symptoms when diagnosed often find it particularly difficult to accept a gluten-free diet. Indeed, some doctors have questioned the need for a strict gluten-free diet in such people given the lifestyle restrictions that such a diet can pose. However, several lines of evidence would support adhering to a gluten-free diet even in those without symptoms:
WHAT IS THE PROGNOSIS? — The majority of patients completely respond to a gluten-free diet and go on to lead a normal life. Approximately 70 percent of those with symptoms at diagnosis notice an improvement in intestinal symptoms (such as diarrhea) within two weeks of beginning a gluten-free diet; in others, the response is more gradual. The skin lesions present in some patients with celiac disease (dermatitis herpetiformis) may take several months to resolve. The response to some of the other associated conditions is variable.
The most common reason for failure to respond is inadvertent ingestion of gluten-containing foods. However, other disorders mimicking celiac disease should be considered in those who continue to have symptoms despite a gluten-free diet.
Are there possible complications? — In addition to anemia, bone loss, and other consequences of malabsorption, a very small percentage of patients develop intestinal symptoms that do not respond to a gluten-free diet, a condition called "refractory sprue." Some patients with refractory sprue have a condition known as "ulcerative jejunitis" in which the small intestine develops multiple ulcers that do not heal. Treatment involves medications designed to suppress the immune system. Cancer of the lymph system (lymphoma) is also an uncommon but recognized complication of long-standing celiac disease. Other types of cancers may also be more common in people with untreated celiac disease than the general population, although the actual risk is very low.
IMPLICATIONS FOR YOUR FAMILY — Your family will need to adjust to your new diet. Thus, it may be helpful for them to share in your education about celiac disease.
Another issue related to your family is that the risk of celiac disease is increased in the relatives of those with celiac disease. Thus, first-degree relatives (a parent, brother, sister, or child) of a person who has been diagnosed with celiac disease should consider being screened for the disease, which is typically accomplished with blood antibody testing as described above. You should discuss these issues with your doctor.
Follow your health care provider's instructions for rest, activity, medicine, and diet. Your provider will probably suggest that you:
After a few days, you may return to normal eating, carefully adding back any of the foods that sometimes cause diarrhea.
If you have cramps or abdominal pain, it may help to put a hot water bottle or electric heating pad (set on low) on your abdomen.
If your health care provider prescribes a new antibiotic, take all of the medicine as prescribed.
Call your health care provider if: