Molina‐Infante, Javier

Consensus diagnostic recommendations to distinguish GORD from eosinophilic oesophagitis (EoE) by response to a trial of proton pump inhibitors (PPIs) unexpectedly uncovered an entity called ‘PPI-responsive oesophageal eosinophilia’ (PPI-REE). PPI-REE refers to patients with clinical and histological features of EoE that remit with PPI treatment. Recent and evolving evidence, mostly from adults, shows that patients with PPI-REE and patients with EoE at baseline are clinically, endoscopically and histologically indistinguishable and have a significant overlap in terms of features of Th2 immune-mediated inflammation and gene expression. Furthermore, PPI therapy restores oesophageal mucosal integrity, reduces Th2 inflammation and reverses the abnormal gene expression signature in patients with PPI-REE, similar to the effects of topical steroids in patients with EoE. Additionally, recent series have reported that patients with EoE responsive to diet/topical steroids may also achieve remission on PPI therapy. This mounting evidence supports the concept that PPI-REE represents a continuum of the same immunological mechanisms that underlie EoE. Accordingly, it seems counterintuitive to differentiate PPI-REE from EoE based on a differential response to PPI therapy when their phenotypic, molecular, mechanistic and therapeutic features cannot be reliably distinguished. For patients with symptoms and histological features of EoE, it is reasonable to consider PPI therapy not as a diagnostic test, but as a therapeutic agent. Due to its safety profile, ease of administration and high response rates (up to 50%), PPI can be considered a first-line treatment before diet and topical steroids. The reasons why some patients with EoE respond to PPI, while others do not, remain to be elucidated.

SummaryBackgroundRecent advances in eosinophilic oesophagitis (EoE) have confirmed the existence of a new disease phenotype, proton pump inhibitor (PPI)‐responsive oesophageal eosinophilia (PPI‐REE).AimTo summarise evidence supporting the use of PPI therapy in patients with suspected EoE (oesophageal dysfunction plus >15 eos/HPF in oesophageal biopsies).MethodsA literature search was conducted through MEDLINE, using the MeSH search terms ‘eosinophilic oesophagitis’, ‘proton pump inhibitors’ and ‘oesophageal eosinophilia’. Relevant articles and their reference lists were identified through manual review.ResultsTen articles, including 258 patients with suspected EoE (152 children, 106 adults) undergoing clinico‐histological re‐evaluation after PPI therapy, were identified. In children, clinical response ranged from 78% to 86% and histological remission from 23% to 40%. In adults, symptom response ranged from 25% to 80% and histological remission from 33% to 61%. Among PPI‐REE patients with oesophageal pH‐monitoring, 35 showed pathological and 10 normal studies. PPI‐REE was significantly commoner with documented gastro‐oesophageal reflux disease (GERD) when compared to patients with negative pH monitoring (70% vs. 29%, P < 0.001). Symptom improvement/resolution occurred in 50–85% of patients without histological remission on PPI therapy. Six PPI‐REE patients demonstrated clinico‐histological relapse on PPI therapy.ConclusionsAt least one third of patients with suspected EoE achieve clinico‐histological remission on PPI therapy. Response is more limited in children compared with that in adults. pH monitoring does not accurately predict response to PPI therapy, albeit histological remission is significantly higher, up to 70%, upon documented GERD. Symptom improvement is common with PPI therapy despite persistent eosinophilic infiltration.