The role of lymphocytes in eosinophilic gastrointestinal disorders

Eosinophilic gastrointestinal diseases (EGIDs) encompass a variety of disorders including eosinophilic esophagitis (EE), eosinophilic gastroenteritis (EG), and eosinophilic colitis. Although the pathogenesis of EGIDs is still poorly understood, dietary food antigens have been shown to cause EGIDs through several short-term clinical studies. The relationship of EGIDs with food allergy points to a potential breach of oral tolerance in EGIDs and to a potentially important role played by lymphocytes in responding to the oral food antigens. This article discusses the concept of oral tolerance, the available evidence for the role that lymphocytes play in the induction and pathogenesis of EGIDs, and the evidence for a potential breach in oral tolerance in EGIDs.