Edit to say: What she said...lol. Here is the LONG version of the answer.

What they are looking for is a condition called Selective IgA Deficiency. There are sort of two categories of this.

Total IgA deficiency is of the most concern, and is defined (from what I have read) as an IgA level less than 7. If someone has total IgA deficiency they can run into problems if ever needing a blood transfusion.

Below range IgA is also considered being "IgA deficient", and may make one more prone to general illness, food sensitivity, and such, but isn't considered as big of a deal. Most often, people never even find out they are low in IgA.

My daughter, like you, falls just below normal range. She does have more than her fair share of common colds, throat infections, sinus infections, urinary tract infections, etc. As a child, she couldn't get a cold without it "turning" into a sinus infection, ear infection, etc. Have you been plagued by increased general illness or infections?

How is it related to celiac disease?

There is a higher prevalnce of IgA deficiency in those with celiac disease than in the general public, and there is a higher prevalence of celiac disease in those with IgA deficiency. Increased association both ways.

The bigger issue in diagnostic testing for celiac disease is that any of the IgA tests used for celiac screening are not reliable measures in people who are IgA deficient. If you don't make IgA, you can't show IgA on these tests. So, then it is important to also test the IgG versions of the test... and it looks like they have done that.

Good for your doctor for checking Total IgA and running the IgG versions of the tests. That is a loophole sometimes left open.

However, there is another loophole I see, and it involves the Deamidated gliadin antibody. This is a newer test, replacing the original gliadin antibody test.

The original gliadin antibody test was not considered specific to the finding of villous atrophy (required for a celiac disease diagnosis). The deamidiated gliadin antibody test was developed to be a better predictor of villous atrophy.

The loophole is that you can have gluten sensitivity without having celiac disease. This is something gaining recognition over the past years, but not quite to the point of complete, widespread acceptance.

So... on the one hand... in regard to predicting "celiac disease"... the deamidated gliadin test is a better test than the previous one. Step forward for diagnosing celiac disease (villous atrophy). This may help reduce the number of unnecessary biopsies.

BUT... big BUT... when it comes to diagnosing gluten sensitivity that is manifesting without villous atrophy... the newer deamidated gliadin test becomes as worthless as the anti-tissue transglutaminase test (also very specific for villous atrophy). Neither of these tests will be positive unless someone has villous atrophy. You can absolutely be gluten sensitive and symptomatic without having villous atrophy; without being positive on these blood tests. Step backward for diagnosing gluten sensitivity.

If your doctor is willing, try to get the original antigliadin antibody test ordered. You are more likely to test positive on the original gliadin antibody test than on the newer deamidated gliadin test.

Still, you should now, many people who test negative even on the original antigliadin test often improve on a gluten free diet. The blood tests are not perfect. When it comes to gluten sensitivity without celiac disease, the rate of "false negative" lab results increase. Hence, the popularity of the stool test for identifying crytpic gluten sensitivity.

It should be noted that even in cases of biopsy proven celiac disease, blood tests are negative in up to 20%. This is why if someone is highly symptomatic of celiac disease, they should be biopsied even when blood tests are negative.

I know I just dumped a lot here. Please ask for clarification if it doesn't all make sense.

Here are a couple of articles about IgA deficiency... keep in mind the distinction between IgA deficiency and Total IgA deficiency.

Celiac Disease and Immunoglobulin A Deficiency... by Kumar, et al.

Here are a couple others... the link was broken for the article I usually reference.. but this should help.
http://pediatrics.about.com/od/prima...deficiency.htm
http://www.nlm.nih.gov/medlineplus/e...cle/001476.htm

It might not be a bad idea to test for IgG subclass deficiencies as well.

And, here are some links to pages of The Gluten File that might help clarify some things on Gluten Sensitivity vs. Celiac Disease, Diagnostic Testing, etc. You can also scan the right bar for topics that may be of interest, particularly if there is any family history of other autoimmune disease.

Diagnostic Testing
The Gray Zone
Limitations of Blood / Biopsy
Gluten Sensitivity vs. Celiac Disease
At Risk Population for Gluten Sensitivity/Celiac Disease


Hope this helps!

Cara

I went gluten free primarily to support my daughter. My antibody tests were all negative. But, before long, a life time of nagging GI symptoms just vanished. I've also realized I am sensitive to cow's milk protein, too, as is my daughter. I say... if the shoe fits... wear it... I would absolutely recommend a gluten free diet if you are symptomatic in any way or have any family history of autoimmune disease!

My family's story can be found in The Gluten File at the bottom of the home page, if you are interested. My family is gluten sensitive, but we do not have celiac disease.