The role of biologics in the pathogenesis and treatment of eosinophilic esophagitis

Abstract

Eosinophilic esophagitis (EoE) is a chronic immune-mediated disorder characterized by inflammation, and intraepithelial infiltration of eosinophils in the esophageal epithelium. It is associated with unbearable symptoms, such as dysphagia, and bolus impaction which affect the nutritional status, and quality of life of the patients. It is diagnosed from a thorough medical history, and confirmed by endoscopy and esophageal biopsy. Traditionally, it has been treated with elimination diet, proton pump inhibitors, and swallowed topical corticosteroids. However, several of the patients with EoE are refractory to the treatment. Eosinophilic esophagitis like eosinophilic asthma is a T helper type 2 lymphocyte (Th2)-mediated allergic disease. During an allergic inflammation Th2 cells secrete cytokines, such as interleukin-5 (IL-5). IL-4, and IL-13 which play a key role in the pathogenesis of EoE. Th2 cytokines promote eosinophilopoiesis, differentiation, proliferation, maturation and activation of eosinophils. Activated eosinophils liberate several cytotoxic cationic proteins, and reactive oxygen species which cause epithelial injury, inflammation, and remodeling, which later progresses to esophageal fibrosis. Dupilumab (dupixent®)is a monoclonal antibody which target the IL-4 receptor (IL-4Rα) which signals for both IL-4 and IL-13. Dupilumab is the only biologic which is effective, and approved for the treatment of EoE in adults and children 12 years and older. Treatment with dupixent® has been shown to improve dysphagia, dilate and relax the gullet, and allow patients to enjoy their cherished dish. Biologics such as dupilumab should be administered early in patients with EoE in order to prevent the menacing complications of the disease, such as esophageal stricture, and esophageal perforation, which necessitate surgical esophageal dilatation, and repair.