Background: Patients with well-controlled celiac disease (CeD) show markedly heterogeneous mucosal injury during standardized gluten exposure. We asked whether duodenal mucosa already carries a molecular signature that predicts subsequent susceptibility to gluten-induced damage.
Methods: We performed a post hoc longitudinal analysis of paired duodenal biopsies from placebo-treated CEC-3 clinical study participants undergoing 6 weeks of gluten challenge (3 g per day, n=24; 1,2). Baseline duodenal bulk RNA-seq obtained on a gluten-free diet was modeled in relation to post-challenge villus height-to-crypt depth ratio (VH:CrD), adjusting for baseline VH:CrD, using continuous limma-voom modeling. An immune/regulatory candidate space of >500 curated genes was interrogated, and convergence was assessed with the externally defined HALLMARK_INTERFERON_GAMMA_RESPONSE set. As an orthogonal sensitivity analysis, baseline expression within this Hallmark set was tested against individual histologic change (ΔVH:CrD=post−pre).
Results: Baseline transcriptomic variation was associated with subsequent mucosal injury despite clinical control on a gluten-free diet. In the primary baseline-adjusted analysis, TAP1, PSMB9, HLA-B, and IRF9 met the FDR<0.10 threshold for association with lower post-challenge VH:CrD, within a broader IFN-γ/antigen-processing program also comprising HLA-A, IRF1, BST2, B2M, IFI27, PARP14, and CCL5. The ΔVH:CrD sensitivity analysis reproduced this directionally coherent program. Strongest deterioration-associated effects were observed for HLA-B (β=−0.35), IRF9 (β=−0.33), and PSMB9 (β=−0.32), with concordant recurrence of IFI27, HLA-A, BST2, TAP1, B2M, IRF1, PARP14, and CCL5. Opposing positive associations included TRIM14, CFB, and MVP, suggesting a distinct resilience-associated state.
Conclusions: Clinically controlled CeD mucosa retains pre-existing molecular heterogeneity that marks subsequent vulnerability to gluten. Convergence across baseline-adjusted and change-score analyses identifies an IFN-γ/antigen-presentation axis as a robust candidate marker of mucosal susceptibility and a potential stratification framework for gluten-challenge studies.