Abstract
Background/Objectives: Histological follow-up still lacks consensus in the long-term management of adult patients with celiac disease (CD) adhering to a gluten-free diet (GFD). Despite clinical and serological improvement, a significant proportion of patients continue to have persistent villous atrophy. We aimed to synthesize current evidence regarding histological outcomes after GFD treatment in adult CD, focusing on mucosal healing rates, assessment methods, and remission criteria. Methods: We conducted a literature search with extraction and analysis of published cohort studies that included adult patients with CD on GFD with follow-up biopsy data. Extracted parameters included demographic details, baseline histology, GFD duration and adherence, serologic status, and histologic recovery rates with corresponding remission criteria. Results: Data from 46 studies comprising 15,530 patients were analyzed. The overall mean age was 41 years, and 73.3% were female. Mean histologic remission across cohorts was 58.8%, with considerable interstudy variation. Remission criteria also varied widely, ranging from strict Marsh 0 control histology to more inclusive definitions that considered Marsh 1 or even non-atrophic mucosa (Marsh < 3) as indicative of recovery, while some studies relied on quantitative villous height-to-crypt depth ratio thresholds, substantially influencing reported remission rates. Longer GFD duration and rigorous diet adherence assessment using validated questionnaires and accurate laboratory tools were associated with higher remission rates. Conclusions: Histologic remission in GFD-treated adult patients with CD is highly variable and strongly influenced by remission definitions and adherence assessment methods. Standardized reporting using validated metrics for histologic outcome and dietary compliance is essential for harmonizing follow-up strategies in adult CD.