Proton pump inhibitor responsive esophageal eosinophilia, a distinct disease entity?

Effect of Proton Pump Inhibitor Treatment in "PPI Non-responsive" Patients with Eosinophilic Esophagitis

BACKGROUND AND AIMS

Some eosinophilic esophagitis (EoE) patients can have a decline in eosinophil count after proton pump inhibitor (PPI) treatment without achieving histologic response, but little is known about this group. We aimed to determine the effect of PPIs on reducing esophageal eosinophilia in patients deemed non-responsive to PPI therapy.

METHODS

We analyzed prospectively collected cohort data from newly diagnosed adults with EoE who were histologic non-responders (≥15 eos/hpf) to PPI-only therapy. Symptoms, endoscopic histologic features were assessed before and after PPI. Pre- and post-PPI treatment esophageal biopsies were read by pathologists to determine peak eosinophil counts and other histologic findings.

RESULTS

Of 125 patients, peak eosinophil counts were 102.1 ± 69.8 and 102.9 ± 101.1 (p=0.93) before and after PPI treatment, respectively, but lamina propria fibrosis decreased from 97% to 41% (p<0.001). Heartburn frequency also decreased (19% to 11%; p=0.006), though endoscopic findings did not change. There were 75 patients (60%) who had some decrease in eosinophil counts, with 30 patients (24%) having ≥50% decrease in counts. When comparing the ≥50% and <50% decrease groups, differences in endoscopic features were identified, but the ≥50% group had improvement in eosinophil degranulation, microabscesses, spongiosis, and basal cell hyperplasia.

CONCLUSION

Peak eosinophil counts did not decrease overall after PPI treatment, but symptoms of heartburn improved. Approximately a quarter had ≥50% decrease in eosinophil counts, with associated decreases in other histologic findings. Further research may consider what role PPIs have in this subset of non-responders or in combination therapies.

Eosinophilic esophagitis. The North against the South? A bio-economic-social mechanistic approach and clinical implications

Eosinophilic esophagitis is a chronic antigen-mediated disease characterized by esophageal symptoms, esophageal eosinophilia, and the absence of response to proton pump inhibitors. It is the most frequent cause of dysphagia and food impaction in adults. Its incidence and prevalence is very high in the developed countries (USA, Europe, Australia), where its connotation is that of an emerging epidemic. While studies have been published with large case series in the developed countries, those published in Latin America are small or consist of isolated case reports. The differences in the prevalence of the disease between the developed and developing regions are unknown. Genetic or racial causes have been cited. Nevertheless, the epidemic nature of the disease suggests that environmental causes are the most powerful. Based on the published hypotheses, as well as on epidemiologic studies, the present review discusses some of the possible causes of the disparity in the prevalence of eosinophilic esophagitis between the two types of countries. The 'hygiene hypothesis' is reviewed, together with the possible relation of Helicobacter pylori, intestinal parasites, and modifications of the esophageal microbiota in patients with eosinophilic esophagitis. In reference to studies conducted in the United States, the clinical behavior and progression of eosinophilic esophagitis in Hispanics is reviewed and a possible predominant phenotype in Mexican and other Latin American patients is discussed. Finally, based on the above, an algorithm for studying the disease in the Latin American countries is proposed.

Lack of compliance with consensus recommendations on the diagnosis of eosinophilic esophagitis (EoE) in published prevalence studies. A clinical and systematic review

OBJECTIVE

According to consensus recommendations, the presence of esophageal symptoms, >15 eosinophils/high-power field and unresponsiveness to proton pump inhibitors are required for a diagnosis of eosinophilic esophagitis (EoE). Nevertheless, inconsistency in using these guidelines has been reported in recent publications. The objective of this study was to assess compliance with EoE diagnostic guidelines in published studies on EoE prevalence and to evaluate other clinical and methodological parameters.

METHODS

A systematic review was conducted in articles published between 2008 and 2015 on the prevalence of EoE in unselected adults. Studies using EoE diagnostic definitions were judged to be compliant if they included all three components of the definition, partially compliant if they included two and non-compliant if they included one or none. Esophageal biopsy protocol differences and descriptions of patients' characteristics were determined.

RESULTS

Among the 20 studies included, eight were performed in a hospital setting and 12 in the general population. Only 40.0% of studies were compliant, 35.0% were partially compliant and 25.0% were non-compliant with the EoE diagnostic definition guidelines. In 60.0% of the studies a proton pump inhibitor trial was not administered. Only 30.0% adhered to the recommendations in the esophageal biopsy protocol. A lack of description of the history of atopia and endoscopic characteristics was observed in many studies.

CONCLUSIONS

Partial or non-compliance with the EoE diagnostic definition was observed in most of the published prevalence studies after the publication of the first consensus. The results of these studies might be interpreted taking into account this context.

Eosinophilic Esophagitis, Eosinophilic Gastroenteritis, and Eosinophilic Colitis: Common Mechanisms and Differences between East and West

Background

Eosinophilic esophagitis (EoE), eosinophilic gastroenteritis (EGE), and eosinophilic colitis (EoC) have been diagnosed with an increasing frequency over the last decades. All these diseases share pathogenic similarities with respect to triggering by food antigens in the majority of patients once secondary causes of tissue eosinophilia have been excluded. While diagnostic criteria for EoE have been published, the exact criteria for EGE and EoC still need to be defined. This review highlights similarities and differences between affected patients when comparing the Western with the Eastern world.

Summary

The incidence and prevalence of EoE are on the rise in countries from the Western and Eastern world. Very limited epidemiologic data exist regarding EGE and EoC. Characteristics of patients with eosinophilic gastrointestinal disorders regarding gender distribution, age at diagnosis, and associated comorbidities are similar when comparing Eastern with Western countries. Similar modalities are applied to diagnose EoE, EGE, and EoC when comparing Eastern with Western countries. Additionally, comparable therapeutic measures are applied to treat eosinophilic gastrointestinal diseases in Eastern and Western countries. While EoE treatment recommendations are based on increasingly solid evidence, recommendations for the treatment of EGE and EoC are based on low evidence.

Key Messages

Eosinophilic gastrointestinal diseases are diagnosed and treated using similar approaches in Eastern and Western countries. Further efforts should be undertaken to help clarify the underlying pathogenic mechanisms and to establish evidence-based diagnostic and therapeutic protocols.

Eosinophilic esophagitis: From pathophysiology to treatment

Eosinophilic esophagitis (EoE) is a chronic immune disease, characterized by a dense eosinophilic infiltrate in the esophagus, leading to bolus impaction and reflux-like symptoms. Traditionally considered a pediatric disease, the number of adult patients with EoE is continuously increasing, with a relatively higher incidence in western countries. Dysphagia and food impaction represent the main symptoms complained by patients, but gastroesophageal reflux-like symptoms may also be present. Esophageal biopsies are mandatory for the diagnosis of EoE, though clinical manifestations and proton pump inhibitors responsiveness must be taken into consideration. The higher prevalence of EoE in patients suffering from atopic diseases suggests a common background with allergy, however both the etiology and pathophysiology are not completely understood. Elimination diets are considered the first-line therapy in children, but this approach appears less effective in adults patients, who often require steroids; despite medical treatments, EoE is complicated in some cases by esophageal stricture and stenosis, that require additional endoscopic treatments. This review summarizes the evidence on EoE pathophysiology and illustrates the safety and efficacy of the most recent medical and endoscopic treatments.