CASE-CONTROL STUDY ON VITAMIN D STATUS IN CHILDREN AND ADOLESCENTS WITH EOSINOPHILIC ESOPHAGITIS

Vitamin D Levels as a Potential Modifier of Eosinophilic Esophagitis Severity in Adults

BACKGROUND

Vitamin D deficiency is associated with atopic and immune-mediated diseases but has not been extensively assessed in eosinophilic esophagitis (EoE). We aimed to assess if vitamin D levels in newly diagnosed EoE patients were lower than in non-EoE controls and examine levels in relation to EoE clinical features.

METHODS

This secondary analysis of a prospective cohort study used data and biosamples from adults who underwent outpatient esophagogastroduodenoscopy. Before each procedure, blood was obtained and stored at -80oC. Serum 25-hydroxy-vitamin D3 (25(OH)D3) was measured by ELISA. Levels for cases and controls were compared at baseline. Within cases, 25(OH)D3 levels were compared for clinical, endoscopic, and histologic measures.

RESULTS

We analyzed 40 EoE and 40 non-EoE controls. Mean serum 25(OH)D3 level was slightly lower in EoE patients than controls (30.9 ± 15.3 ng/mL vs. 35.9 ± 15.4; p = 0.15). After controlling for age, sex, and race, adjusted levels were 10.8 ng/mL lower in EoE patients (95% CI: -19.0, -2.5), but 25(OH)D3 deficiency (< 20ng/mL) was similar in cases and controls (20% vs. 15%; p = 0.56). Levels of 25(OH)D3 were not associated with differences in clinical or endoscopic features of EoE, and EREFS and eosinophil counts did not significantly correlate with 25(OH)D3 levels (R of -0.28 [p = 0.08] and - 0.01 [p = 0.93], respectively). 25(OH)D3 levels were lower in EoE cases with lamina propria fibrosis (23.2 ± 9.6 vs. 45.0 ± 17.7; p = 0.03).

CONCLUSIONS

After adjusting for age, sex, and race, 25(OH)D3 levels were lower in EoE cases than controls, but deficiency was not common. 25(OH)D3 levels were generally similar across most EoE disease features.

Vitamin D receptor and STAT6 interactome governs oesophageal epithelial barrier responses to IL-13 signalling

OBJECTIVE

The contribution of vitamin D (VD) deficiency to the pathogenesis of allergic diseases remains elusive. We aimed to define the impact of VD on oesophageal allergic inflammation.

DESIGN

We assessed the genomic distribution and function of VD receptor (VDR) and STAT6 using histology, molecular imaging, motif discovery and metagenomic analysis. We examined the role of VD supplementation in oesophageal epithelial cells, in a preclinical model of IL-13-induced oesophageal allergic inflammation and in human subjects with eosinophilic oesophagitis (EoE).

RESULTS

VDR response elements were enriched in oesophageal epithelium, suggesting enhanced VDR binding to functional gene enhancer and promoter regions. Metagenomic analysis showed that VD supplementation reversed dysregulation of up to 70% of the transcriptome and epigenetic modifications (H3K27Ac) induced by IL-13 in VD-deficient cells, including genes encoding the transcription factors HIF1A and SMAD3, endopeptidases (SERPINB3) and epithelial-mesenchymal transition mediators (TGFBR1, TIAM1, SRC, ROBO1, CDH1). Molecular imaging and chromatin immunoprecipitation showed VDR and STAT6 colocalisation within the regulatory regions of the affected genes, suggesting that VDR and STAT6 interactome governs epithelial tissue responses to IL-13 signalling. Indeed, VD supplementation reversed IL-13-induced epithelial hyperproliferation, reduced dilated intercellular spaces and barrier permeability, and improved differentiation marker expression (filaggrin, involucrin). In a preclinical model of IL-13-mediated oesophageal allergic inflammation and in human EoE, VD levels inversely associated with severity of oesophageal eosinophilia and epithelial histopathology.

CONCLUSIONS

Collectively, these findings identify VD as a natural IL-13 antagonist with capacity to regulate the oesophageal epithelial barrier functions, providing a novel therapeutic entry point for type 2 immunity-related diseases.