Mechanisms of desensitization with oral immunotherapy and epicutaneous immunotherapy

Abstract

Background: Oral immunotherapy (OIT) and epicutaneous immunotherapy (EPIT) are emerging therapies for food allergy. With several recently published exploratory trials and randomized controlled clinical trials that support these procedures, there is a clear progress and interest toward making these treatment options available for allergist/immunologists and patients with food allergies entrusted to their care. However, there still remain many questions and concerns to be addressed before these procedures can be fully understood. Objective: The purpose of the present report is to trace some of the important historical milestones in the development of OIT and EPIT that have contributed to their evolving clinical application to the treatment of food allergy, to describe some of the current understandings of the immunologic mechanisms by which these procedures elicit desensitization, and to provide some areas for future inquiry and research. Methods: An extensive research was conducted in the medical literature data bases by applying terms such as food allergy, desensitization, tolerance, unresponsiveness, Treg cells, allergen immunotherapy (AIT), oral immunotherapy (OIT), and epicutaneous immunotherapy (EPIT). Results: OIT and EPIT take their origins from AIT (also called desensitization), a procedure first reported for the treatment of hay fever over a 100 years ago in which slowly increasing doses of a specifically relevant allergen were administered until a maintenance dosage was achieved when the patient was free of symptoms. OIT and EPIT differ from AIT in certain aspects including the route of administration of the allergen as well as their relative shorter period of sustained unresponsiveness. Conclusion: The origins and important historical landmarks that have been made in the field of food allergy immunotherapy are presented in the context of the immunologic mechanisms that contribute to the pathogenesis of these disorders. Although considerable progress has been made in recent years toward making these treatment options available for allergist/immunologists and patients with food allergies, there still remain many questions and concerns to be addressed before these procedures can be fully understood, which can be illuminated by future research.