About the Blood Tests for CD

There are several blood tests for Celiac Disease, so the first thing to know is which one(s) you had! If you don't have your actual lab results, you can ask for a copy from your doctor's office. You may need to fill out a request form due to the privacy laws, but asking for a copy of the test is fine - people do it all the time.

If you read any journal articles about medical tests, they will refer to the sensitivity and specificity of the tests. What does this mean? These terms are a measure of the "trueness" of the test. Sensitivity is the chance that a person who really does have an illness, really will have a positive test. Specificity is the chance that a person who does not have an illness will have a negative test. In evaluating a test, you would want the sensitivity and specificity to be as close to 100% as possible.

Antigliadin antibody IgA (AGA-IgA), Antigliadin antibody IgG (AGA-IgG)
Positive antigliadin antibodies mean that the body is reacting against gliadin, one of the gluten proteins in wheat. A large percentage of the population has antibodies against gliadin, and many are apparently healthy, so the interpretation of this test has been very confusing. In fact, these tests are no longer recommended as a screening tool for CD...and yet they are still run. A positive antigliadin antibody, with a negative tTG test and biopsy, can cause a lot of concern when it appears in family members. What does this type of test result mean - if anything? A study has been published that follows people who had only antigliadin antibodies.

Gliadin Peptide antibody
A new test with good performance. This measures a reaction to the broken-down gluten molecule (peptide). These peptides are an integral part of the reaction to gluten in Celiac Disease and this test is showing good results in diagnosis.

Tissue Transglutaminase antibody IgA

Tissue Transglutaminase antibody IgG

Endomysial antibody IgA

HLA Type

Anti-actin antibody

Positive blood tests / negative biopsy

Negative blood tests