Abstract and Introduction
Abstract
Background Recent advances in eosinophilic oesophagitis (EoE) have confirmed the existence of a new disease phenotype, proton pump inhibitor (PPI)-responsive oesophageal eosinophilia (PPI-REE).
Aim To summarise evidence supporting the use of PPI therapy in patients with suspected EoE (oesophageal dysfunction plus >15 eos/HPF in oesophageal biopsies).
Methods A 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.
Results Ten 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.
Conclusions At 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.
Introduction
Eosinophilic oesophagitis (EoE) has dramatically emerged over the last decade as a prevalent cause of gastrointestinal morbidity in adults and children. In fact, scientific publications have nearly doubled since the first consensus guidelines for diagnosis of EoE were published in 2007. It is currently considered the second cause of chronic oesophagitis after gastro-oesophageal reflux disease (GERD) and the first cause of food impaction in young patients. EoE is a chronic inflammatory disorder, confined to the oesophagus, characterised clinically by oesophageal dysfunction (mainly dysphagia and food impaction) and histologically by eosinophil-predominant inflammation (usually a minimum of 15 eosinophils per high power field (eos/HPF)).
The presence of oesophageal eosinophilia, however, is not specific and may occur in a variety of disorders including GERD, EoE, eosinophilic gastroenteritis, coeliac disease, achalasia, inflammatory bowel disease, infection, hypereosinophilic syndrome, vasculitis, drug and/or iatrogenic-induced states such as caustic injury, multiple convulsive therapy syndrome and immunosuppression following solid organ transplantation. The diagnosis of EoE, thus, requires exclusion of other possible causes of oesophageal eosinophilia. In 2007, the first consensus guidelines established that EoE could be distinguished from GERD by either normal oesophageal acid exposure on oesophageal pH monitoring or persistent oesophageal eosinophilia despite high-dose acid suppressive therapy, with the assumption that only GERD responds to proton pump inhibitor (PPI) therapy. Nonetheless, the complex relationship between EoE and GERD has become increasingly acknowledged with evolving evidence.
In 2006, a case series presented two children and an adult with clinical, endoscopic and histological data suggestive of EoE, which all completely responded to PPI therapy. This study raised the question as to whether these three patients had GERD or could EoE respond to a pharmacological effect of PPIs independent of acid suppression. Since then, several studies have confirmed the existence of patients with clinical symptoms of oesophageal dysfunction and oesophageal eosinophilia responsive to PPI therapy. As such, the 2011-updated guidelines for the diagnosis of EoE highlighted the description of a new potential disease phenotype, the PPI-responsive oesophageal eosinophilia (PPI-REE).
The aim of this review is to summarise the evidence over the last decade supporting the use of PPI therapy in patients with an EoE profile in clinical practice, noting the impact of PPI therapy on either clinical and histological outcomes and the role of pH monitoring to predict response to PPI therapy.