Eosinophilic esophagitis: an allergist's approach

Steroids therapy for eosinophilic esophagitis: Systematic review and meta-analysis

OBJECTIVE

We designed this systematic review and meta-analysis aiming to clarify the advantage of steroid therapy compared with non-steroid therapy for the treatment of eosinophilic esophagitis (EoE).

METHODS

PubMed, EMBASE, Medline, ISI Web of Science and the Cochrane Database of Systematic Reviews were searched to identify relevant randomized controlled trials (RCTs) comparing steroid and non-steroid therapy, and retrospective and prospective trials on steroid therapy for EoE. RevMan 5.2 was used for the analysis. Weighted mean difference and 95% confidence interval (CI) were estimated and pooled using meta-analysis methods.

RESULTS

Six RCTs including 193 participants fulfilled the inclusion criteria for meta-analysis, and another two RCTs, three prospective and five retrospective trials were included in systematic review. Meta-analysis showed that topical steroids significantly decreased the mean and peak esophageal eosinophils (EOS) count compared to non-steroid therapy (MDmean  = -23.41, 95% CImean -42.08--4.73, P = 0.01 and MDpeak  = -51.27, 95% CIpeak -78.62--23.92, P = 0.0002). There were 14 trials showing the efficacy of steroids on decreasing the EOS count, 10 showing the amelioration of symptoms, and five showing endoscopic improvement. Only mild adverse events were reported for topical steroids.

CONCLUSIONS

Steroids are effective on decreasing the EOS count in EoE patients. Its value in ameliorating symptoms and endoscopic changes remains undetermined due to the lack of comparable criteria.

Esophageal rupture as a primary manifestation in eosinophilic esophagitis

Eosinophilic esophagitis (EoE) is a chronic inflammatory process characterized by symptoms of esophageal dysfunction and, histologically, by eosinophilic infiltration of the esophagus. In adults, it commonly presents with dysphagia, food impaction, and chest or abdominal pain. Chronic inflammation can lead to diffuse narrowing of the esophageal lumen which may cause food impaction. Endoscopic procedures to relieve food impaction may lead to complications such as esophageal perforation due to the friability of the esophageal mucosa. Spontaneous transmural esophageal rupture, also known as Boerhaave's syndrome, as a primary manifestation of EoE is rare. In this paper, we present two adult patients who presented with esophageal perforation as the initial manifestation of EoE. This rare complication of EoE has been documented in 13 other reports (11 adults, 2 children) and only 1 of the patients had been previously diagnosed with EoE. A history of dysphagia was present in 1 of our patients and in the majority of previously documented patients. Esophageal perforation is a potentially severe complication of EoE. Patients with a history of dysphagia and patients with spontaneous esophageal perforation should warrant an evaluation for EoE.

Elevated levels of leukotriene C4 synthase mRNA distinguish a subpopulation of eosinophilic oesophagitis patients

BACKGROUND

Cysteinyl leukotrienes contribute to Th2-type inflammatory immune responses. Their levels in oesophageal tissue, however, do not distinguish patients with eosinophilic oesophagitis (EoE) from controls.

OBJECTIVE

We asked whether mRNA levels of leukotriene C4 synthase (LTC4 S), a key regulator of leukotriene production, could serve as a marker for EoE.

METHODS

Digital mRNA expression profiling (nCounter(®) Technology) was performed on proximal and distal oesophageal biopsies of 30 paediatric EoE patients and 40 non-EoE controls. Expression data were confirmed with RT-qPCR. LTC4 S mRNA levels were quantified in whole blood samples. Leukotriene E4 was measured in urine.

RESULTS

LTC4 S mRNA levels were elevated in proximal (2.6-fold, P < 0.001) and distal (2.9-fold, P < 0.001) oesophageal biopsies from EoE patients. Importantly, increased LTC4 S mRNA transcripts identified a subpopulation of EoE patients (28%). This patient subgroup had higher serum IgE levels (669 U/mL vs. 106 U/mL, P = 0.01), higher mRNA transcript numbers of thymic stromal lymphopoietin (TSLP) (1.6-fold, P = 0.009) and CD4 (1.4-fold, P = 0.04) but lower IL-23 mRNA levels (0.5-fold, P = 0.04). In contrast, elevated levels of IL-23 mRNA were found in oesophageal biopsies of patients with reflux oesophagitis. LTC4 S mRNA transcripts in whole blood and urinary excretion of leukotriene E4 were similar in EoE patient subgroups and non-EoE patients.

CONCLUSION & CLINICAL RELEVANCE

Elevated oesophageal expression of LTC4 S mRNA is found in a subgroup of EoE patients, concomitant with higher serum IgE levels and an oesophageal transcriptome indicative of a more-pronounced allergic phenotype. Together with TSLP and IL-23 mRNA levels, oesophageal LTC4 S mRNA may facilitate diagnosis of an EoE subpopulation for personalized therapy.

Eotaxin and FGF enhance signaling through an extracellular signal-related kinase (ERK)-dependent pathway in the pathogenesis of Eosinophilic esophagitis

Background

Eosinophilic esophagitis (EoE) is characterized by the inflammation of the esophagus and the infiltration of eosinophils into the esophagus, leading to symptoms such as dysphagia and stricture formation. Systemic immune indicators like eotaxin and fibroblast growth factor were evaluated for possible synergistic pathological effects. Moreover, blood cells, local tissue, and plasma from EoE and control subjects were studied to determine if the localized disease was associated with a systemic effect that correlated with presence of EoE disease.

Method

Real-time polymerase chain reaction from peripheral blood mononuclear cells (PBMC), immunohistochemistry from local esophageal biopsies, fluid assays on plasma, and fluorescence-activated cell sorting on peripheral blood cells from subjects were used to study the systemic immune indicators in newly diagnosed EoE (n = 35), treated EoE (n = 9), Gastroesophageal reflux disease (GERD) (n = 8), ulcerative colitis (n = 5), Crohn's disease (n = 5), and healthy controls (n = 8).

Result

Of the transcripts tested for possible immune indicators, we found extracellular signal-regulated kinase (ERK), Bcl-2, bFGF (basic fibroblast growth factor), and eotaxin levels were highly upregulated in PBMC and associated with disease presence of EoE. Increased FGF detected by immunohistochemistry in esophageal tissues and in PBMC was correlated with low levels of pro-apoptotic factors (Fas, Caspase 8) in PBMC from EoE subjects. Plasma-derived bFGF was shown to be the most elevated and most specific in EoE subjects in comparison to healthy controls and disease control subjects.

Conclusion

We describe for the first time a possible mechanism by which increased FGF is associated with inhibiting apoptosis in local esophageal tissues of EoE subjects as compared to controls. Eotaxin and FGF signaling pathways share activation through the ERK pathway; together, they could act to increase eosinophil activation and prolong the half-life of eosinophils in local tissues of the esophagus in EoE subjects.

Eosinophilic oesophagitis: clinical manifestations and treatment options. The role of the allergologist

Eosinophilic oesophagitis (EO) is an infrequent disorder that is currently underdiagnosed. It has been described in both adults and in children, and is more prevalent among males. The etiology of EO is not clear, though atopy has been suggested as playing an important role in the development of the disease. The clinical presentation of EO is varied, and a differential diagnosis with other digestive tract disorders is required particularly gastro-oesophageal re-flux. Dysphagia and food bolus impactation within the oesophagus are the most characteristic symptoms. Diagnostic confirmation is obtained from multiple oesophageal biopsy, with the detection in some sample or samples of over 15 eosinophils per high-magnification microscopic field. An allergological study is needed to evaluate the existence of allergens (perennial or seasonal environmental allergens and food allergens) responsible for the eosinophilic infiltration found at oesophageal level. There is no specific treatment for EO, and topical corticosteroids (swallowed) are currently the pharmacological treatment of choice. Dietary therapy in children with food allergy as the causal factor may prove effective, though the existence of polysensitisation complicates the correct implementation of such treatment. Oesophageal dilatation is reserved for cases with severe dysphagia, and is not without complications. Treatment with anti-IL-5, antileukotrienes, azathioprine, 6-mercaptopurine, anti-IgE, etc., could constitute alternatives to topical corticosteroids, although information is still lacking on their long-term safety and efficacy in the paediatric population.

Eosinophilic esophagitis: management and pharmacotherapy

Eosinophilic esophagitis represents the most debated disease of the last 10 years, too often speculated or overestimated and certainly well known and examined. The aim of this study was to summarize the recent therapeutic trends in order to show persistent doubts regarding several debated therapies. The study combined the most recent international literature and the authors' daily experience to define the scope of the review, with limits caused by a lack of available randomized studies between dietetic and pharmacological treatment. It was concluded that eosinophilic esophagitis is an immunoallergic disease that is generally caused by identifiable food and environmental allergens although, in a minority of cases, the etiological trigger remains undetermined. Therapy usually fights the responsible agents, but sometimes they are not resolved. A need for more pathogenetically driven treatments is invoked.

Eosinophilic esophagitis: association with allergic disorders

Atopy has been linked to eosinophilic gastrointestinal disorders because of the role eosinophils play in atopic disorders. It has also been found that these disorders coexist. The goal of this article is to take a step back, and considering only eosinophilic esophagitis, attempt to determine from the available body of clinical and research literature: (1) Is the coexistence of these disorders attributable to a preconceived bias? If so, what is the source of the bias and how can it be removed? (2) Is there a cause and effect relationship? If so, can this relationship be harnessed for diagnostic and therapeutic modalities?