Alicia Woodward: Hi! I am Alicia Woodward, editor of 'Living Without,' the worlds leading magazine for people with food allergies and sensitivities.

Today I'd like to talk with you about testing for Celiac disease. The gold standard for diagnosing Celiac disease is the intestinal biopsy. Blood tests are useful first step in identifying people who should undergo a biopsy.

The American Gastroenterological Association recommends beginning with a tTG screening which measures antibodies via a blood test. The deamidated gliadin peptides or DGP is the newest Celiac test and it is showing up more often. When run together, the DGP and the tTG test yield highly accurate results.

Early reports in the medical literature suggest that if you're positive by both, the DGP and tTG tests the certainly of having Celiac disease is high. When blood tests are unclear or when a patient is already on the gluten free diet, a genetic test may help clarify the diagnosis. When negative, a genetic test rules out the likelihood of Celiac disease in almost all cases.

Sometimes blood tests for Celiac disease are falsely negative, and there are several reasons for this. The first is eating gluten free. For accurate results your diet must currently contain gluten. Certain health conditions, such as IGA deficiency which is an immune deficiency disorder that affects up to 4% of those with Celiac disease can also cause false negatives.

Very young children may get false negatives, because their immune systems aren't mature enough to manufacture some of the antibodies the test picks up. It's also important to keep in mind that no test is a 100% perfect all the time. The test itself may fall short. In addition, an inexperienced lab may yield an accurate test results or there maybe errors in interpreting the data.

Ask your doctor to use a laboratory that specializes in Celiac disease. If your blood test and biopsy come back negative, your doctor may rule our Celiac disease. If you continue to have symptoms when you eat gluten, you maybe gluten sensitive, a condition that responds well to the gluten-free diet.