Do You Have Celiac Disease and Have Questions Or Need Help?
Join Celiac.com's forum / message board and get your questions answered! Our forum has nearly 1 MILLION POSTS, and over 62,000 MEMBERS just waiting to help you with any questions about celiac disease and the gluten-free diet. We'll see you there!
Follow / Share
|Get Email Alerts|
- Safe Gluten-Free Food List (Safe Ingredients)
- Unsafe Gluten-Free Food List (Unsafe Ingredients)
- Gluten-Free Alcoholic Beverages
- Celiac Disease Symptoms
- The Gluten-Free Diet 101 - A Beginner's Guide to Going Gluten-Free
- Interpretation of Celiac Disease Blood Test Results
- Is Buckwheat Flour Really Gluten-Free?
How accurate are blood-antibody tests?*
In 1994 I was diagnosed with celiac disease, which led me to create Celiac.com in 1995. I created this site for a single purpose: To help as many people as possible with celiac disease get diagnosed so they can begin to live happy, healthy gluten-free lives. Celiac.com was the first site on the Internet dedicated solely to celiac disease. In 1998 I foundedÂ The Gluten-Free Mall, Your Special Diet Superstore!, and I am the co-author of the book Cereal Killers, and founder and publisher of Journal of Gluten Sensitivity.View all articles by Scott Adams
There are two classes of antibodies seen in untreated celiac disease. Antibodies directed against a fragment of gluten called gliadin, and antibodies directed against a particular tissue in the body itself. The two main areas in the body which can be attacked by its own antibodies are the aendomysial (the covering of muscle), and the reticulin ( the framework for kidney and liver), but there are others.
To conduct the test, 5ccs of blood is drawn from the patient, and the blood cells are removed. The gliadin test is usually an automated machine-read test, which means there is little room for interpretor error. However, currently in the USA there is no standard methods for conducting the test, or normal ranges for the results. The endomysial tests are more dependent on the experience and ability of a pathologist who looks at a pattern of staining produced by the patients serum on a slice of monkey esophagus. While this test is done in similar way in most labs, there are many differences in how the results are interpreted.
How good are these tests?
If all of the blood test results are positive a celiac disease diagnosis is 90% accurate. However, there are several circumstances in which the tests can be inaccurate. IGA and IGG are two different varieties of antibodies which are produced by most peoples immune systems. There is a different blood test for each of the antibodies. Of the two tests, the IGA gliadin and IGA endomysial tests are the most accurate. However, this test can become negative relatively quickly after going on a gluten-free diet (3-6 months), which can cause a false negative test result. The IGG is less specific, and can sometimes be positive in non-celiacs. Also, about 4% of celiacs have no IgA at all! For these reasons it is very important that both tests are done for an accurate diagnosis. The biopsy is still considered the "standard candle" to confirm a blood diagnosis, and give a 100% sure diagnosis.
For all tests for celiac disease it is necessary that one is on a gluten-containing diet, or false-negative test results could be given. Blood tests may also be useful in following up a known celiac and confirm that the diet is indeed free of large amounts of gluten. Also, because of the lack of standardization, keep in mind that blood test results may not be directly comparable from one lab to the next.
Celiac.com welcomes your comments below (registration is NOT required).
What is the difference between celiac disease and gluten intolerance?*
was posted by Kemp Randolph on the Celiac Listserv news group krand@pipeline.... [READ MORE]
How can I determine the amount of gluten from the weight of the wheat in food?
For 100 units of whole grain wheat, about 70 units of
white flour results from the milling process.... [READ MORE]
What about repeat biopsies vs. serology and gluten challenges?
There are different practices amongst GIs on repeat
biopsies vs.... [READ MORE]
What is dermatitis herpetiformis? What does it have to do with celiac disease?
Dermatitis herpetiformis (DH) is a severely itchy
skin condition that often starts abruptly, affecting the elbows,
knees, buttocks, scalp, and back.... [READ MORE]