Acid Reflux and EoE: A Complex Relationship

Often caused by acid reflux, eosinophilic esophagitis (EoE) is an emerging inflammatory disease that is generally unresponsive to proton pump inhibitor (PPI) therapy. A different condition, proton pump inhibitor—responsive esophageal eosinophilia (PPI-REE), responds symptomatically and histologically with PPI therapy. Although it is not considered EoE, PPI-REE is phenotypically and genotypically indistinguishable from EoE.

A pair of researchers explored the link between gastroesophageal reflux disease (GERD) and EoE in the journalBest Practice & Research Clinical Gastroenterology. They found that PPIs provide benefit in 33% of patients with EoE whose esophageal pH monitoring indicates nonpathological disease. EoE and PPI-REE mucosal disruption were also found to be independent of acid exposure, although the researcher suggested that patients with EoE and acid hypersensitivity may benefit from taking PPIs.

Additionally, PPIs appear to reverse inflammatory gene expression in PPI-REE as strongly as steroids benefit patients with EoE. PPI therapy in PPI-REE significantly downregulates inflammatory markers in the distal and proximal esophagus, just as topical steroids do in patients with EoE. However, EoE may cause acid reflux through stricture formation, and EoE co-existence with GERD may be coincidental.

Suggesting that EoE and PPI-REE will soon be considered the same disease, the researchers predicted that the standard of care for EoE will shift to include PPIs as firstline therapy, while second-line therapy will include restricted diet and steroids. Further research is needed to determine whether esophageal barrier impairment is the cause or the effect of EoE and whether PPIs primarily target barrier integrity or esophageal inflammation.