Expression microarray analysis identifies novel epithelial-derived protein markers in eosinophilic esophagitis.

Area of Science:

• Gastroenterology
• Immunology
• Molecular Biology

Background:

• Eosinophilic esophagitis (EoE) has an immune-mediated etiology with altered inflammatory and epithelial gene expression.
• Characterizing epithelial gene expression changes in EoE is crucial for understanding disease mechanisms.

Purpose of the Study:

• To further characterize epithelial gene expression alterations in eosinophilic esophagitis.
• To evaluate the diagnostic utility of specific epithelial-derived markers using immunohistochemistry.

Main Methods:

• Gene expression microarray and RT-PCR were used on esophageal biopsies from pediatric EoE patients before and after steroid therapy.
• Immunohistochemistry was performed on a larger cohort of EoE patients, reflux patients, and normal controls to assess protein expression of identified markers.

Main Results:

• Overexpression of ALOX15 and TNFAIP6, and underexpression of FLG, SLURP1, and CRISP3 were identified in EoE.
• ALOX15 and TNFAIP6 showed high specificity and sensitivity for EoE, correlating with eosinophilic infiltration.
• FLG and SLURP1 were significantly underexpressed in EoE and recovered after therapy, while CRISP3 was also reduced.

Conclusions:

• Five epithelial-derived markers (ALOX15, TNFAIP6, FLG, SLURP1, CRISP3) are differentially expressed in eosinophilic esophagitis.
• These markers are detectable by immunohistochemistry and hold potential for diagnostic applications in EoE.
• The findings support the role of epithelial dysfunction in the pathogenesis of eosinophilic esophagitis.