Very high TTG-IGG, low overall IGA

[MashaMom]

Hi, my 12 yo daughter has complained for months of headaches, stomaches, nausea.  She says she doesn't feel well nearly daily and has frequent rashes.  She's able to go to school and play sports and is generally a happy normal kid but she's starting to ask to skip activities bc of how she feels.  Her bloodwork was as follows: overall serum IGA is Lower than normal (28) but not deficient.  Her TTG-IGA is normal.   Based on the low IGA, her PCP ordered a TTG-IGG which came back extremely elevated.  She referred us to a specialist.  He seemed extremely skeptical of celiac and was surprised she had run the TTG-IGG at all because that's not a test they typically ever use.  He wants to rerun all the tests.  My reading of the literature is that this is not necessarily diagnostic but that the next step would be an endoscopy.  I think we'll get there.  But in the meantime, any ideas what this super elevated IGG test could mean? It was off the charts (>250 u/ml) so it can it really be just a random abnormal lab value with no meaning?

[trents]

From the article linked: If the initial Immunoglobulin A (IgA) test is lower than normal, then these two tests should be done:

1. Tissue transglutaminase antibodies, IgA and IgG profle.

2. Gliadin (deamidated) antibodies evaluation, IgG and IgA.

From your post: "Based on the low IGA, her PCP ordered a TTG-IGG which came back extremely elevated."

Your PCP seems to know more about testing for celiac disease than does the specialist.

[Scott Adams]

As the article states:

Quote

The sensitivity of the tTG-IgG blood test is generally high, ranging from 85% to 98%. This means that the test can accurately detect celiac disease in a significant percentage of people who have the condition.

The specificity of the tTG-IgG blood test is also high, typically around 90% to 98%. This indicates that the test can effectively rule out celiac disease in individuals who do not have the condition.

Be sure she keeps eating gluten daily until all testing is completed.