Serum IFABP level as an index of mucosal health in celiac disease: a small intestinal morphometry study.

INTRODUCTION: To evaluate the correlation between serum intestinal fatty acid binding protein (IFABP) levels and quantitative duodenal morphometry in adult celiac disease (CeD) patients at diagnosis and after long-term gluten-free diet (GFD), and to assess the role of this investigation as a non-invasive marker of mucosal injury and healing. METHODS: In this prospective cross-sectional study, adult CeD patients on a GFD for ≥18 months (follow-up = FU) and newly diagnosed untreated CeD patients (ND) were enrolled. Serum IFABP levels were measured by ELISA. Duodenal biopsies from FU and ND CeD patients underwent quantitative morphometric analysis, including villous height to crypt depth ratio (Vh:Cd), intraepithelial lymphocyte (IEL) count, and calculation of the Vh:Cd and IEL scale (VCIEL) index. Correlation between IFABP and histological parameters was assessed. RESULTS: IFABP levels were significantly higher in ND patients compared with FU (p<0.001). Across the cohort, IFABP levels correlated negatively with Vh:Cd ratio (ρ= -0.53, p<0.001) and positively with IEL count (ρ=0.46, p<0.001). IFABP also showed a strong inverse correlation with the VCIEL index (ρ= -0.60, p<0.001). In FU patients, IFABP remained significantly associated with subtle morphometric abnormalities, including reduced Vh:Cd ratio and increased IELs, but not with celiac serology or self-reported dietary adherence. CONCLUSIONS: Serum IFABP levels represent a promising, non-invasive biomarker of enterocyte damage for capturing subtle changes and current mucosal status in CeD patients on a long-term GFD, when conventional serology and dietary questionnaires may fail.