How Well Do Celiac Disease Blood Tests Work in Kids?

True or False: False-Negative Celiac Blood Tests More Common in Kids

Getty Images/Arthur Tilley

Question: How well do celiac disease tests work in kids? Is it true that false negative celiac test results are common in kids?

Answer: A so-called "false negative" test result occurs when the results of a medical test indicate you don't have a particular condition (in this case, celiac disease), but you really do. The medical test isn't deliberately lying to you — few tests offer 100% certainty in their results.

It's common to read on various celiac disease forums that children often have false negative results on tests for celiac disease (especially on celiac blood tests).

The reasoning behind this is that the celiac-related intestinal damage known as villous atrophy takes a long time to develop, and so children with negative results simply haven't had enough time for the condition to progress to the really damaged stage (positive blood tests indicate damage is present).

This sounds like a good theory, but unfortunately there's no medical evidence to back it up — the studies just haven't been done.

What Do We Know About Testing Kids for Celiac?

According to Dr. Alessio Fasano, who heads the University of Maryland Center for Celiac Research, overall false negatives on one particular celiac disease blood test — the tTG-IgA test — generally occur in about 10-15% of all cases. However, there hasn't been any research to determine whether children are more prone to these false negatives than adults.

"To assess the sensitivity of a test like tTG, first you perform endoscopies with biopsies and then confirm how many of the biopsies showing damage indicative of celiac disease are positive for tTG," Dr. Fasano told me. "These kinds of studies have been done in adults who can undergo endoscopies more frequently and for many more reasons than kids.

In the pediatric population, this approach would not be ethically justifiable, and I'm not aware of any such studies."

There is some evidence for a false negative rate in children that's somewhat higher than 10-15%.

A study published in 2011 in the journal Clinical Chemistry and Laboratory Medicine looked at blood test and biopsy results in a group of celiac children under age six who had both tests. The study found that 80% of these biopsy-confirmed celiac disease patients had positive test results in either the deamidated gliadin peptide (DGP) IgA blood test or in the tTG-IgA blood test. A total of 84% of the children were positive in either the DGP-IgG or the tTG-IgA blood test.

Therefore, the authors concluded that the best chances for an accurate blood test result come when the tTG-IgA test is used in combination with the DGP IgG test. In that study, the "false negative" rate for those two recommended blood tests used in combination was 16%. Using the other combination of tests yielded a false negative rate of 20%.

I Think the Test Was A False Negative. Now What?

If you believe your child's celiac disease test results came back with a false negative result, you potentially have a couple of options that you can discuss with your pediatrician, especially if your child's symptoms scream "celiac." (Check out my article on Celiac Disease Symptoms in Children if you're not sure.)

It's possible that, despite the negative blood test results, your child's physician might recommend going ahead with an endoscopy to determine if there's any intestinal damage that could indicate celiac. Although many parents stress over subjecting their child to an endoscopy (and there is some slight risk, just as there is with any medical procedure), the truth is that the children usually cope far better than the parents on endoscopy day.

You might also decide to skip the endoscopy, but consider going ahead with a trial of the gluten-free diet to see if symptoms resolve. Your child may not have celiac disease, but may instead have non-celiac gluten sensitivity, a newly-recognized condition with symptoms that closely mimic celiac. There's currently no universally accepted way to test for gluten sensitivity, but if your child suffers from the condition, her symptoms should improve rapidly when she avoids gluten in her diet.

Finally, you could consider genetic testing for celiac disease. These tests can't diagnose celiac; instead, they only can determine if you have the genetic potential to develop the condition. (For more on this, see my article What if my celiac gene test was positive?)

The bottom line is, there's little evidence for a much higher rate of false negative celiac disease blood test results in children than there is in adults — it's possible that about one in every five or six children tested receives a false negative result. Fortunately, you do have some options if you believe your child's test results aren't correct.

Continue Reading