The role of mast cells in eosinophilic esophagitis

Eosinophilic esophagitis (EE) is a chronic inflammatory disease of the esophagus which is characterized by the presence of dense infiltrate of eosinophilic leukocytes restricted to this organ mucosa. Accumulating published evidence suggests a strong role of mast cells in the inflammatory infiltrate in the physiopathology of EE. We have reviewed published articles with relevant information about the presence and possible role of mast cells in EE. Although mast cells have been studied indirectly in EE, reported data allow us to confirm that the number of mast cells infiltrating the esophageal epithelium in adult and child patients with EE is higher with respect to the normal state and in gastroesophageal reflux disease. Mast cells linked to IgE, which are not found in other conditions, have been identified in EE. Despite that fact, an anaphylactic reaction history after exposure to allergens is not common in these patients. Therefore, the mast cells' function in EE could be dependent on T lymphocytes, as suggested by a mast cell gene expression analysis. Bi-directional crosstalk is established between mast cells and eosinophils, hence establishing interesting hypotheses regarding their relationship to EE physiopathology. Mast cells' function as an immune response leader seems to substitute for their effector functions in EE, while at the same time opening new research pathways for consideration of these cells as a therapeutic target in EE. However, the inefficiency of therapies that inhibit mast cell functions while they are effective in other respiratory tract diseases results in the need for specific studies to identify the real function of such complex cells in the physiopathology of EE. There is indirect proof of the role of mast cells in EE, while many doubts exist about their activation mechanism, which does not seem to be IgE-mediated. Specific approach studies are needed to clarify the function of these cells in the physiopathology of EE, which could be a possible therapeutic target.