Eosinophilic esophagitis: epithelial mesenchymal transition contributes to esophageal remodeling and reverses with treatment

Dietary therapy can reverse esophageal subepithelial fibrosis in patients with eosinophilic esophagitis: a historical cohort

BACKGROUND

Fibrosis of the esophageal lamina propria is a known complication of eosinophilic esophagitis (EoE). To date, therapy with topical corticosteroids has been shown to reverse esophageal fibrosis in some patients; however, there is little evidence to suggest that dietary therapy can also reverse it. Our aim was to examine whether dietary therapy alone can reverse esophageal fibrosis in children with EoE.

METHODS

We performed a historical cohort study based on children with EoE who had esophageal fibrosis on pretreatment biopsies using trichrome staining. Post-treatment biopsies were analyzed for fibrosis reversal, and results were compared between patients treated with dietary restriction and those that received topical steroids. Clinical characteristics (age, symptoms, duration of symptoms prior to therapy, treatment type, and duration of therapy) were recorded. Histological markers (eosinophil numbers and eosinophilic degranulation in both epithelium and lamina propria, basal zone hyperplasia, and the presence of eosinophilic microabscesses in the epithelium) were examined by reviewing hematoxylin and eosin-stained biopsies and by immunohistochemical staining. These were examined as potential predictors for fibrosis reversal.

RESULTS

Fibrosis resolved following both dietary restriction and topical steroids (3/17 and 5/9 patients respectively, P = 0.078). Post-treatment symptom resolution and decreased intraepithelial eosinophil numbers were found to be the only significant predictors of fibrosis resolution.

CONCLUSIONS

Dietary restriction alone, similar to topical steroids, can reverse fibrosis in children with EoE.

Eosinophilic gastrointestinal diseases--clinically diverse and histopathologically confounding

Eosinophilic gastrointestinal diseases are a group of chronic diseases characterized by a range of symptoms caused by eosinophilic inflammation of various parts of the gastrointestinal tract. Other causes for eosinophilia need to be ruled out prior to making the diagnosis of EGIDs. The most common form of EGID is eosinophilic esophagitis (EoE), an antigen-driven disease that afflicts children and adults and has been identified across the world. Histological features include dense eosinophilia of the esophageal mucosa, eosinophil degranulation, eosinophil microabscess formation, and other features of epithelial inflammation including basal zone hyperplasia and rete pege elongation. Treatments include dietary exclusions and topical corticosteroids.

MicroRNA profiling in mucosal biopsies of eosinophilic esophagitis patients pre and post treatment with steroids and relationship with mRNA targets

Background

The characterization of miRNAs and their target mRNAs involved in regulation of the immune process is an area of intense research and relatively little is known governing these processes in allergic inflammation. Here we present novel findings defining the miRNA and mRNA transcriptome in eosinophilic esophagitis (EoE), an increasing recognized allergic disorder.

Methods

Esophageal epithelial miRNA and mRNA from five paired biopsies pre- and post-treatment with glucocorticosteroids were profiled using Taqman and Affymetrix arrays. Validation was performed on additional paired biopsies, untreated EoE specimens and normal controls. Differentially regulated miRNAs and mRNAs were generated, within which miRNA-mRNA target pairs with high predicted confidence were identified.

Results

Compared to the post-glucocorticoid treated esophageal mucosa, of all the 377 miRNA sequences examined, 32 miRNAs were significantly upregulated and four downregulated in the pre-treated biopsies. MiR-214 was the most upregulated (150 fold) and miR-146b-5b, 146a, 145, 142-3p and 21 were upregulated by at least 10 fold. Out of 12 miRNAs chosen for validation by qRT-PCR, five (miR-214, 146b-5p, 146a, 142-3p and 21) were confirmed and 11 shared the same trend. When the expression of the 12 miRNAs in the EoE mucosa was compared to unrelated normal mucosa, six (miR-214, 146b-5p, 146a, 21, 203, and 489) showed similar significant changes as in the paired samples and 10 of them shared the same trend. In the same five pairs of samples used to profile miRNA, 311 mRNAs were down-regulated and 35 were up-regulated in pre-treated EoE mucosa. Among them, 164 mRNAs were identified as potential targets of differentially regulated miRNAs. Further analysis revealed that immune-related genes, targeted and non-targeted by miRNAs, were among the most important genes involved in the pathogenesis of EoE.

Conclusions

Our findings add to the accumulating body of data defining a regulatory role for miRNA in immune and allergic processes.