Dr. Nelson?
http://www.uams.edu/celiac/FAQs/FAQframe.htm

Quote:

Strict GF diet should result in decreases in antibody titers over time. EMA (tTG) will go down first, usually negative by 4-6 months. IgA gliadin next then IgG gliadin which may persist for a year.

Another study has shown that patients (who were ultimately diagnosed with CD) with equivocal biopsies when given large "doses" of gluten containing protein over 2 month period will develop the typical changes of villous flattening. This is also known as a "Gluten Challenge".