[Eosinophilic esophagitis. Review of current clinical and physiopathological concepts].

Eosinophilc esophagitis (EE) is an emerging disease which is characterized by a dense infiltration of the esophagus by eosinophilic leukocytes. The main symptoms of this disease are dysphagia and frequent food impaction in esophagus, and they are due to a hypersentivity response to different foods or aeroallergens. Eosinophil accumulation in the esophageal epithelium is determined by local production of eosinophilotropic cytokines and chemokines, which have been well defined as a TH2-type hypersensitivity reaction in animal models of the disease. Esophageal epithelium, after T CD4+ lymphocytes stimulation, contains all the necessary cell types for the development of local immunoallergic responses. However, there is increasing data on the significant role that humoral immunity could play in the pathophysiology of EE, by means of the action of IgE over mast cells function. The high density of T CD8+ lymphocytes in inflammatory infiltrate suggests that a TH1-type reaction could also participate in the mechanism of the disease. Proteins contained in cytoplasmic granules of activated eosinophils and mast cells could act over neural and muscular components of the esophageal wall, triggering motor disturbances which can be measured by means of manometric recordings and justify the esophageal symptoms. This paper aims to review the newest clinical aspects of EE and the results of studies directed at investigating the pathophysiology of the disease. Furthermore, we carry out a critical review of available therapeutic options.