Gluten Sensitivity /
Celiac Disease

Alternative Names: Also classified as a disease of nutrient malabsorption, celiac disease is also known as celiac sprue, nontropical sprue and gluten-sensitive enteropathy.

Celiac disease is a digestive disease that damages the small intestine and interferes with absorption of nutrients from food.  People who have celiac disease cannot tolerate a protein called gluten (or a gluten fraction called gliadin), which is found in wheat, rye, barley, and possibly oats. Gluten is a protein found in wheat, rye, barley, and oats that gives dough it's sticky quality.  An inability to digest these grains is called celiac disease.

Incidence; Causes and Development; Contributing Risk Factors

Approximately 0.5% of Americans have symptoms brought on by this condition.  About 10% of an affected person's first-degree relatives (parents, siblings or children) will also have the disease.  It has also been estimated that up to 20% of Americans have the disease to some degree.

When people with celiac disease eat foods containing gluten, their immune system responds by damaging the small intestine.  Specifically, tiny fingerlike protrusions, called villi, on the lining of the small intestine are lost.  Nutrients from food are absorbed into the bloodstream through these villi.  Without villi, a person becomes malnourished - regardless of the quantity of food eaten.

There is increasing evidence that most people with gluten sensitivity have latent celiac disease with such mild manifestations in the digestive tract that the diagnosis is never made.  An allergy or intolerance to specific grains, such as wheat, may be due to a gluten sensitivity, but may occur for other reasons as well.

Celiac disease is considered an autoimmune disorder because the body's own immune system causes the damage.

Celiac disease runs in families.  Sometimes the disease is triggered by surgery, pregnancy, childbirth, viral infection or severe emotional stress.  Celiac disease affects people differently; some develop symptoms as children, others as adults.  One factor thought to play a role in when and how celiac appears is whether and how long a person was breastfed - the longer one was breastfed, the later and more atypical the symptoms appear.  Other factors include the age at which one began eating foods containing gluten and how much gluten has been eaten.

Signs and Symptoms

Symptoms may or may not occur in the digestive system.  For example, one person might have diarrhea and abdominal pain, while another person has irritability or depression.

Symptoms include mood swings (down after eating and up after avoidance), severe depression, anxiety, irritability, compulsive behavior, "schizophrenia" symptoms, and other mental disorders.

Diagnosis and Tests

To diagnose celiac disease, physicians test blood to measure levels of antibodies to gluten.  These antibodies are antigliadin, anti-endomysium and antireticulin.  If the tests and symptoms suggest celiac disease, the physician may remove a tiny piece of tissue from the small intestine to check for damage to the villi.  Gluten sensitivity should not be self-diagnosed, since other medical problems could be the cause of similar symptoms.  A gluten-free diet should not be followed until you have been seen by your doctor.  Tests for celiac disease cannot produce a proper diagnosis if a person is not currently reacting to gluten in their diet.  Once a diagnosis is made and a person responds to the gluten-free diet, the physician will know for certain that the diagnosis of celiac disease is correct.

Screening for celiac disease involves testing asymptomatic people for the antibodies to gluten/gliadin.  Because celiac disease is hereditary, family members - particularly first-degree relatives - of people who have been diagnosed may need to be tested for the disease.

Complications

While the gastrointestinal tract is the primary target organ, systemic disease is an important consequence of gluten ingestion in many patients.  Latent disease may manifest itself as irritable bowel syndrome with iron deficiency anemia, but little or no diarrhea.  There is increasing evidence that most people with gluten/gliadin sensitivity have latent celiac disease with such a mild manifestation that the diagnosis is never made.  The undamaged part of their small intestine is able to absorb enough nutrients to prevent symptoms.  However, people without symptoms are still at risk for the complications of celiac disease.

The longer a person goes undiagnosed and untreated, the greater the chance of developing malnutrition and other complications.