Can Anyone Explain The Low Iga Issue

[Elaine40]

My daughter's IGA showed <3 (with a negative being <11 and 11 to 17 being equivocal and >17 positive). Her IGG was 7 with negative being <11.

The TTG antibody, IGG was <3

The TTG antibody, IGA was also <3, so negative for both.

She has actually been retested and we are waiting the results because for some reason the hematologist thought that the other doctor didn't do the full panel. Does this sound like the full panel, and does the IGA seem low. I've seen a few things on low IGA affecting the celiac test.

Thank you.

[happygirl]

From Columbia University's Celiac Disease Center:

"Serologic panel

Of the commercially available serologic tests that aid in the diagnosis of celiac disease, no one test is ideal. Using multiple serologies increases the diagnostic yield. Therefore, in the United States, screening in patients with possible celiac disease should consist of a panel of the following serologic tests:

Anti-gliadin antibodies (AGA) both IgA and IgG

Anti-endomysial antibodies (EMA) - IgA

Anti-tissue transglutaminase antibodies (tTG) - IgA

Total IgA level.

The reason for the use of the panel to detect celiac disease is several fold. They include selective IgA deficiency (SIgA deficiency), lack of concordance of endomysial antibody and tTG, and the occurrence of seronegative celiac disease. "

When you hear about "low IgA", it is in reference to total or serum IgA. If you are IgA deficient, then your other IgA tests won't be as accurate...which is why you need the full panel run.

"Selective IgA deficiency (SIgA deficiency)

SIgA deficiency occurs 10 to 15 times more commonly among people with celiac disease compared to the general population [19]. Patients with SIgA deficiency will lack IgA antibodies including endomysial antibody, tTG and IgA AGA. To detect celiac disease in patients with SIgA deficiency an IgG antibody, typically IgG AGA, needs to be performed together with total IgA level. Alternatively, one may screen with IgG anti- EMA or IgG anti-tTG, though these are not widely available. Typically the patient with celiac disease and SIgA deficiency will have a positive IgG AGA and absent total IgA level. This combination should prompt a biopsy, whereas an isolated positive IgG AGA would usually not. "

Your hematologist is right---they didn't run the full panel.

If the total serum IgA is low, it affects the other IgAs. If you AGA IgA is normal, and your serum IgA is normal, then it means you are testing within normal limits.

[Elaine40]

Thanks so much. That was really helpful. Hopefully we'll get the results of the second testing today.

[happygirl]

Elaine,

Happy to help. I hope that you find some much needed answers!

Laura