Toll-like receptors-mediated pathways activate inflammatory responses in the esophageal mucosa of adult eosinophilic esophagitis.

OBJECTIVES: Esophageal microbiota and regulation of adaptive immunity are increasingly being investigated in eosinophilic esophagitis (EoE). Toll-like receptors (TLRs) play a central role in the initiation and maintenance of innate immune activity. Our objective was to characterize the esophageal and duodenal innate immune response in EoE and its modulation by dietary therapy. METHODS: Esophageal and duodenal biopsy samples were collected from 10 adults with untreated EoE, before and after effective treatment with a six-food elimination diet (SFED), and 10 controls with normal esophagus. In all cases, bacterial load (by mRNA expression of 16S), TLRs, mucins, transcription factors, interleukins, components of the NKG2D system, and innate immunity effectors were assessed by qPCR. Protein expression of TLRs were also determined by immunofluorescence. RESULTS: Bacterial load and TLR1, TLR2, TLR4, and TLR9 were overexpressed on biopsies with active EoE compared with controls. Muc1 and Muc5B genes were downregulated while Muc4 was overexpressed. Upregulation of MyD88 and NFκB was found together with IL-1ß, IL-6, IL-8, and IL-10 mediators and PER-1, iNOS, and GRZA effectors. NG-K2D components (KLRK1, IL-15, MICB) were also upregulated. In all cases, changes in active EoE were normalized following SFED and mucosal healing. Duodenal samples also showed increased expressions of TLR-1, TLR-2, and TLR-4, but not 16S or any other mediators nor effectors of inflammation. CONCLUSIONS: Esophageal TLR-dependent signaling pathways in EoE support the potential implication of microbiota and the innate immune system in the pathogenesis of this disease.

Subepithelial collagen deposition, profibrogenic cytokine gene expression, and changes after prolonged fluticasone propionate treatment in adult eosinophilic esophagitis: a prospective study.

BACKGROUND: Recent research shows that both pediatric and adult patients with eosinophilic esophagitis (EoE) experience esophageal remodeling marked by increased collagen deposition in which TGF-ß plays an important role. However, limited data are available on the intensity and reversibility of fibrous remodeling in adults with EoE. OBJECTIVE: We sought to analyze differences in collagen deposition in the lamina propria (LP) and profibrogenic cytokine gene expression along with other changes induced by prolonged treatment with fluticasone propionate in adults with EoE. METHODS: Ten adults given consecutive diagnoses of EoE were studied prospectively. Deep esophageal biopsy specimens were obtained before and after 1 year of treatment with fluticasone propionate. Collagen deposition in the LP was assessed in tissue sections with the aid of the Masson trichrome technique. IL5, TGFB1, fibroblast growth factor 9 (FGF9), and CCL18 gene expression was quantified through real-time PCR. EoE results were compared among samples from 10 adult patients with gastroesophageal reflux disease and 10 control subjects with healthy esophagi. RESULTS: Patients with EoE showed a significant increase in subepithelial collagen deposition; this correlated positively with eosinophil density in the LP and the patient's age. Prolonged steroid treatment induced a nonsignificant reduction in subepithelial fibrosis, which remained significantly higher than in control subjects. Profibrogenic cytokine gene expression also increased in patients with EoE, with IL5 (P < .001), FGF9 (P = .005), and CCL18 (P = .008) all significantly upregulated. After 1 year of treatment, a reduction was observed in gene expression; for CCL18 expression, this decrease was statistically significant (P < .001). CONCLUSIONS: Esophageal remodeling is associated with upregulated gene expression of profibrogenic cytokines in adults with EoE. Prolonged treatment with fluticasone propionate leads to a nonsignificant reduction in subepithelial collagen deposition accompanied by downregulation of profibrogenic cytokine gene expression, with that of CCL18 being especially significant.

Montelukast was inefficient in maintaining steroid-induced remission in adult eosinophilic esophagitis.

BACKGROUND AND AIMS: Leukotriene D4 is produced by and functions as a chemotactic factor for eosinophils. Eosinophilic esophagitis (EoE) is characterized by esophageal eosinophilic infiltration, determining structural changes and dismotility symptoms. Montelukast, a selective leukotriene D4 receptor antagonist, has gained increasing consideration as a therapeutic agent for EoE. However, limited available information has shown that montelukast is not effective in reducing eosinophilic infiltration. Our paper aims at evaluating whether montelukast could be consider as a steroid-sparing therapy by assessing its efficacy in maintaining both clinical and histopathological remission achieved after topical corticosteroids in adult EoE patients. METHODS: Eleven consecutively diagnosed adult EoE patients were prospectively studied. Esophageal biopsies were obtained before and after a 6-month treatment with fluticasone propionate 400 µg/twice a day. Immediately after that, montelukast 10 mg/day was instituted. A new endoscopy was foreseen after a new 3-month period, or as soon as the patients presented esophageal symptoms. Symptoms were assessed by using a questionnaire before and after fluticasone propionate treatment and after montelukast therapy. RESULTS: Eosinophils density into the esophageal epithelium and lamina propria was significantly reduced after a 6-month treatment with topical steroids (P = 0.003) and increased to levels similar to baseline level into the first 3 months after treatment with montelukast. Baseline symptom scores significantly decreased after treatment with topical steroids (P = 0.003) and increased again after montelukast therapy, but baseline levels improved. CONCLUSIONS: Montelukast was not efficient in maintaining the histopathological or clinical response achieved by topical steroids in adult EoE patients.