The main aim of this study was to assess whether the complete healing of duodenal mucosa in patients with persistent Mars I-II lesions after 1 year on GFD i) could be achieved, as a proof of the concept, by the adoption of a GCED OR ii) may depend upon time of exposure to GFD. To achieve this aim investigators studied 2 cohorts of patients with Marsh I-II lesion after 1 year on GFD: cohort A re-byopsied after 3 month GCED , and cohort B re-biopsied after a minimum of further 2 years on standard GFD.