Proton-pump inhibitor-responsive esophageal eosinophilia

Area of Science:

• Gastroenterology
• Immunology
• Allergy

Background:

• Proton-pump inhibitor-responsive esophageal eosinophilia (PPI-REE) is a phenotype of eosinophilic esophagitis (EoE).
• PPI-REE patients achieve remission with proton-pump inhibitor (PPI) therapy.
• This review covers the latest evidence on PPI-REE.

Purpose of the Study:

• To review the evolving evidence on the novel phenotype of PPI-REE over the past year.
• To understand the clinical characteristics and treatment response in PPI-REE.
• To explore the underlying mechanisms of PPI therapy in PPI-REE.

Main Methods:

• Review of prospective series and in-vitro/in-vivo studies.
• Comparison of clinical, endoscopic, and molecular characteristics of PPI-REE and EoE.
• Analysis of PPI therapy's effects on esophageal mucosal integrity and Th2 cytokine expression.

Main Results:

• PPI-REE occurs in 30-40% of adults with suspected EoE.
• PPI-REE and EoE are indistinguishable at baseline based on clinical, endoscopic, and molecular markers.
• PPI therapy partially restores esophageal mucosal integrity in PPI-REE and downregulates Th2 cytokines, suggesting anti-inflammatory effects beyond acid suppression.

Conclusions:

• PPI-REE is a common clinical phenotype that is largely indistinguishable from EoE at baseline.
• PPI therapy's anti-inflammatory effects, mediated by Th2 pathway inhibition, likely contribute to epithelial restoration in PPI-REE.
• PPI-REE and EoE may represent the same disease with different treatment responses.