Is Igg Really Clinically Irrevelant?

[organicmama]

After having gluten, wheat, and casein IgG tests show positive, Aetna is denying coverage. Evidently they believe all IgG tests are meaningless and "clinically irrelevant." I swear I feel mentally better after the diet change. Our pediatrician especially orders these on a routine basis.

Is the clinical irrelevance really true, under debate, or another way to avoid paying for many things?

[Skylark]

The mainstream view is that IgG testing is not clinically relevant, particularly IgG4. The problem is that you can have IgG to foods that comes and goes, and IgG shows up a lot more often than actual sensitivities by elimination diets. There is even an argument that IgG protects against IgE mediated allergy, which shows how poorly we understand immunity. It's definitely not diagnostic in the sense that the celiac panel would be.

That said, don't write off the fact that you're feeling better. There ARE people around here who have gotten IgG testing and found they can't tolerate some of their IgG foods. I'm just providing the science so you understand the insurance issues, not to say you can't be feeling better!!!

Here is a task force report on IgG4 that says it is not useful. This was done to address all the mail order companies offering the testing to non-physicians.

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This Pubmed article has a section on IgG testing saying it doesn't work well for allergy. It is available for free online.

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Here is another free article by a GI doctor that points out the problems with IgG testing.

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In contrast, this author claims that IgG testing shows promise. Notice that he says it is useful for guiding an elimination diet, which is exactly what you have done.

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[kareng]

I would fight with the doc if you are being required to pay for this. He ordered the medically "iffy" tests. You just went by his advice. He is supposed to be the expert.

[organicmama]

I asked him to order the tests because all four of my children have had IgG food sensitivities, all of which show again now. Can't really dispute a charge for something I requested.

With children's reactions being behavioral and occasional eczema, it's hard to know if they are truly sensitive or not. They are too small to vocalize any neurological issues.

[organicmama]

Skylark, thanks so much for all of the info. I've been reading a few journal articles that do show significance at times, so I will just carry on with elimination and maybe reintroduce in six months depending on how I feel.

Does it mean anything that the IgG levels were normal after elimination for several months and high again once foods were reintroduced?

[Skylark]

You were tested for total IgA and it was normal, right? If so, I'm not enough of an immunologist to know whether the reappearance of IgG antibodies is clinically significant.

[organicmama]

No, none of us have ever been tested for total IgA.

[Skylark]

You had a celiac panel without total IgA??? Go yell at your doctor.

There is an association between celiac disease and low IgA, so total IgA should always be run with a celiac panel. Low IgA invalidates the IgA tests since people with low total IgA don't make enough to find on tests. Instead you get an IgG celiac panel. This could be what's going on in you and your family with the anti-gliadin IgG coming and going.

[organicmama]

Will testing for that be an issue with us being Gluten-free Casein-free for a month?

[Skylark]

Total IgA? I don't think your diet affects it.