Question About Testing — Total Iga

[Orinda]

Hi all. I had my 5-year-old screened for celiac disease (she's having GI symptoms her sister was biopsy confirmed 5 years ago). They said that she didn't have it (her TTg IgA was less than two), but I asked about her total IgA and was told the following:

 

"Her total IgA was slightly low (hers was 20.1-- our lab says less than 25 is low). We can still trust the TTg IgA until total IgA is less than 10 or so. If you are still concerned, we can do an IgG test for celiac (Deaminated gliadin IgG). I aloready ordered the test so if you wish to procede, you can go to a lab to have it drawn."

 

Any thoughts or opinions? 

[kareng]

"Is an IgA result of 39, where normal is 81-463, considered deficient and could it invalidate anti-IgA tests?

Any level of IgA above 20 mg/dl should make the tTG-IgA test valid, regardless of age."

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Sounds like you are borderline. I would go for the IGG test.

[nvsmom]

I too would do more testing.  Do the tTG IGG, DGP IGG, and you might as well do the DGP IgA to cover all bases.  

 

You may want to consider the biopsy too.  The ttG IGA can have a sensitivity as low as 40%, which means it could miss 60% of celiacs.  The DGP IgG test is better with a sensitivity between 70 and 95%, but it can still miss over a quarter of all celiacs.  If the tests keep coming up negative, and if you suspect celiac disease, a biopsy might be something to consider.

 

This is where I got my info:

 

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A low IgA is more common among celiacs (1 in 20) than in the regular population (about 1 in 700).  Having low IgA can be something to make doctors consider celiac disease testing in and of itself.

 

Best wishes.