Question Regarding Positive Blood Tests

[Helena]

If people test positive for the serological markers for celiac disease, dr.'s generally recommend the biopsy while the patient is still on a gluteny diet---if the biopsy is negative, they decide that the patient does not have celiac.

What I don't get is how they explain the positive blood test results. In my understanding (and I might be entirely wrong here--correct me if I am) if you put anti-tTG in a test tube along with tissue transglutaminase the autoantigen (anti-tTG) will attack the enzyme (tTG). So wouldn't that mean that regardless of the state of the villi that anti tissue transglutaminase is initiating an autoimmune response??

I should add that the answer to this question has no bearing on my life whatsoever. I'm just trying to make sense of the medical system which really doesn't make sense to me sometimes!

[Matilda]

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