Impedance and Histologic Characteristics of the Sub-Laryngeal Esophagus Distinguish Eosinophilic Esophagitis From Other Esophageal Disorders.

BACKGROUND & AIMS: The region of the esophagus 15-17 cm below the incisors, called the sub-upper esophageal sphincter (sub-UES), has not been characterized in adults with eosinophilic esophagitis (EoE) but appears different during endoscopy. We investigated how the sub-UES differs from the remaining esophagus in patients with EoE and aimed to determine whether these differences be used to distinguish patients with EoE from those with lichen planus. METHODS: We performed a prospective study of 14 patients with EoE, 7 patients with lichen planus (based on presence of Civatte bodies, dysphagia, and/or narrow esophagus with thin esophageal mucosa without signs of EoE), and 20 patients undergoing upper endoscopy for upper gastrointestinal or with dysphagia but without features of EoE (controls) at a single medical center from 2015 through 2018. Biopsies from the distal, middle, and sub-UES regions of the esophagus were analyzed by histology, quantitative PCR, and immunohistochemistry. We measured mucosal impedance (MI) in all subjects at the sub-UES and 2 cm, 5 cm, and 10 cm from the gastro-esophageal junction. RESULTS: Patients with EoE had significantly fewer eosinophils (median, 2 eosinophils/high-powered field [HPF]; range, 0-8 eosinophils/HPF) in sub-UES tissues compared with distal esophagus (median, 50 eosinophils/HPF; range, 22.5-60.8 eosinophils/HPF; P < .0001) or middle esophagus (median, 32 eosinophils/HPF; range, 19.3-60; P < .0001). Sub-UES tissues from patients with EoE had significantly less basal cell hyperplasia (P < .01), papillary elongation (P < .01), and dilated intercellular spaces (P < .01) than middle or and distal esophagus. MI in the sub-UES did not differ significantly between patients with EoE vs controls (P = .24), but was significantly lower in patients with lichen planus (median, 1344 ohms; range, 1046-1488) than patients with EoE (median, 2880 ohms; range, 2149-4858) (P < .001). mRNA and protein expression patterns did not differ significantly in the sub-UES of patients with EoE vs controls, except for expression of desmoglein-1, which was increased in sub-UES tissues from patients with EoE. CONCLUSIONS: Sub-UES tissues from patients with EoE differ in numbers of eosinophils, histologic features, and MI compared to controls or patients with lichen planus. These features might help to distinguish these 2 diseases.

Eosinophils Exert Antitumorigenic Effects in the Development of Esophageal Squamous Cell Carcinoma.

BACKGROUND AND AIMS: Eosinophils are present in several solid tumors and have context-dependent function. Our aim is to define the contribution of eosinophils in esophageal squamous cell carcinoma (ESCC), as their role in ESCC is unknown. METHODS: Eosinophils were enumerated in tissues from 2 ESCC cohorts. Mice were treated with 4-NQO for 8 weeks to induce precancer or 16 weeks to induce carcinoma. The eosinophil number was modified by a monoclonal antibody to interleukin-5 (IL5mAb), recombinant IL-5 (rIL-5), or genetically with eosinophil-deficient (ΔdblGATA) mice or mice deficient in eosinophil chemoattractant eotaxin-1 (Ccl11-/-). Esophageal tissue and eosinophil-specific RNA sequencing was performed to understand eosinophil function. Three-dimensional coculturing of eosinophils with precancer or cancer cells was done to ascertain direct effects of eosinophils. RESULTS: Activated eosinophils are present in higher numbers in early-stage vs late-stage ESCC. Mice treated with 4-NQO exhibit more esophageal eosinophils in precancer vs cancer. Correspondingly, epithelial cell Ccl11 expression is higher in mice with precancer. Eosinophil depletion using 3 mouse models (Ccl11-/- mice, ΔdblGATA mice, IL5mAb treatment) all display exacerbated 4-NQO tumorigenesis. Conversely, treatment with rIL-5 increases esophageal eosinophilia and protects against precancer and carcinoma. Tissue and eosinophil RNA sequencing revealed eosinophils drive oxidative stress in precancer. In vitro coculturing of eosinophils with precancer or cancer cells resulted in increased apoptosis in the presence of a degranulating agent, which is reversed with NAC, a reactive oxygen species scavenger. ΔdblGATA mice exhibited increased CD4 T cell infiltration, IL-17, and enrichment of IL-17 protumorigenic pathways. CONCLUSION: Eosinophils likely protect against ESCC through reactive oxygen species release during degranulation and suppression of IL-17.

Eosinophils exert direct and indirect anti-tumorigenic effects in the development of esophageal squamous cell carcinoma.

Background/Aims: Eosinophils are present in several solid tumors and have context-dependent function. Our aim is to define the contribution of eosinophils in esophageal squamous cell carcinoma (ESCC), since their role in ESCC is unknown. Methods: Eosinophils were enumerated in tissues from two ESCC cohorts. Mice were treated with 4-nitroquinolone-1-oxide (4-NQO) for 8 weeks to induce pre-cancer or 16 weeks to induce carcinoma. Eosinophil number was modified by monoclonal antibody to IL-5 (IL5mAb), recombinant IL-5 (rIL-5), or genetically with eosinophil-deficient (ΔdblGATA) mice or mice deficient in eosinophil chemoattractant eotaxin-1 ( Ccl11 -/- ). Esophageal tissue and eosinophil specific RNA-sequencing was performed to understand eosinophil function. 3-D co-culturing of eosinophils with pre-cancer or cancer cells was done to ascertain direct effects of eosinophils. Results: Activated eosinophils are present in higher numbers in early stage versus late stage ESCC. Mice treated with 4-NQO exhibit more esophageal eosinophils in pre-cancer versus cancer. Correspondingly, epithelial cell Ccl11 expression is higher in mice with pre-cancer. Eosinophil depletion using three mouse models ( Ccl11 -/- mice, ΔdblGATA mice, IL5mAb treatment) all display exacerbated 4-NQO tumorigenesis. Conversely, treatment with rIL-5 increases esophageal eosinophilia and protects against pre-cancer and carcinoma. Tissue and eosinophil RNA-sequencing revealed eosinophils drive oxidative stress in pre-cancer. In vitro co-culturing of eosinophils with pre-cancer or cancer cells resulted in increased apoptosis in the presence of a degranulating agent, which is reversed with N-acetylcysteine, a reactive oxygen species (ROS) scavenger. ΔdblGATA mice exhibited increased CD4 T cell infiltration, IL-17, and enrichment of IL-17 pro-tumorigenic pathways. Conclusion: Eosinophils likely protect against ESCC through ROS release during degranulation and suppression of IL-17.