14 Y.O. Daughter's Inconsistent Test Results

[Integrous]

I was diagnosed with celiac disease 12 years ago, so all of my kids get routine blood work to test for celiac disease. My 14-year-old daughter, who has no symptoms, got a <1.0 tTG IgA (normal is <15) and 166 total IgA (normal is 36 to 220).  But, her tTG IgG was 6.8, which is "weakly positive" (normal is <5.99). I understand that a positive result from any test is consistent with a celiac disease diagnosis especially in light of the family history, but I also understand that a negative tTG IgA among patients without IgA deficiency indicates that celiac disease is unlikely. Is there a plausible explanation for her results other than celiac disease? She has an appointment with a GI doctor in 2 months, but is there other blood work she should get in the meantime (e.g., DGP IgA/IgG, EMA IgA)?  Thanks

[RMJ]

It wouldn’t hurt to get the DGP IgA and IgG, and the EMA IgA, so when she sees the GI doctor he/she has the whole serology picture.

[Scott Adams]

This article might be helpful. It breaks down each type of test, and what a positive results means in terms of the probability that you might have celiac disease. One test that always needs to be done is the IgA Levels/Deficiency Test (often called "Total IGA") because some people are naturally IGA deficient, and if this is the case, then certain blood tests for celiac disease might be false-negative, and other types of tests need to be done to make an accurate diagnosis. The article includes the "Mayo Clinic Protocol," which is the best overall protocol for results to be ~98% accurate.