Celiac Disease Diagnosis
Making a diagnosis of celiac disease usually involves a physical exam, a review of the person's symptoms, and blood tests. Based on the results of the blood tests, a biopsy of the small intestine may also be necessary when diagnosing this condition. The final step often involves putting the patient on a gluten-free diet.
In order to make a celiac disease diagnosis, the healthcare provider will typically begin by asking a number of questions (known as the medical history) and perform a physical exam looking for certain signs and symptoms of celiac disease. If he or she believes celiac disease is a possibility, the healthcare provider may also recommend certain tests or procedures. Finally, if the doctor suspects celiac disease, he or she will likely recommend a gluten-free diet.
The Medical History and Physical Exam
The healthcare provider will usually begin by asking a number of questions about subjects such as:
- Current symptoms
- Medical conditions
- Current medications
- A family history of any medical conditions, including celiac disease.
He or she will also perform a physical exam, looking for signs that may point to a diagnosis of celiac disease. During the exam, the doctor will look for things such as signs of malnutrition, weight loss, an unexplained rash, blood in the stool, and bone pain or tenderness.
Tests and Procedures Used to Make a Diagnosis
Recently, researchers discovered that people with celiac disease have higher-than-normal levels of certain autoantibodies in their blood. Antibodies are protective proteins produced by the immune system in response to substances that the body perceives to be threatening. Autoantibodies are proteins that react against the body's own molecules or tissues.
To diagnose celiac disease, physicians will also usually test the person's blood to measure the levels of one or more of the following antibodies:
- IgA anti-tissue transglutaminase (tTGA)
- IgA anti-endomysium antibodies (AEA)
- IgA and IgG anti-gliadin antibodies (AGA).
Before being tested, one should continue to eat a regular diet that includes foods with gluten, such as breads and pastas. If a person stops eating foods with gluten before being tested, the results may be negative for celiac disease, even if the disease is actually present.
If the tests and symptoms suggest celiac disease, the healthcare provider will typically perform a small bowel biopsy. During the biopsy, the healthcare provider removes a tiny piece of tissue from the small intestine to check for damage to the villi. To obtain the tissue sample, the healthcare provider eases a long, thin tube called an endoscope through the mouth and stomach into the small intestine. Using instruments passed through the endoscope, the healthcare provider then takes the sample.