Dual specific oral tolerance induction using interferon gamma for IgE-mediated anaphylactic food allergy and the dissociation of local skin allergy and systemic oral allergy: tolerance or desensitization?
Food allergies are classified as IgE-mediated food allergies (IFAs) and non-IgE-mediated food allergies (NFAs). Recently, oral immunotherapy (OIT) has been found to be successful for treating both IFA and NFA, especially using interferon (IFN) gamma. This study was designed to clarify the clinical characteristics of IFA and NFA and compare the therapeutic characteristics of OIT using subcutaneously administered IFN-gamma for both types of food allergy. In this study, 148 patients were categorized into the IFA and NFA group following food challenge, skin-prick test and food-specific IgE tests. The patients were then treated using protocols specific for IFA and NFA using subcutaneous IFN-gamma injection as a randomized controlled trial. The principle of complete allergy resolution at prior dose in the case of IFA was also evaluated. Only the patients with IFA and NFA treated with OIT using IFN-gamma achieved tolerance successfully. Tolerance was achieved from low-dose range in IFA and in high-dose range for NFA. Complete tolerance was not obtained without achieving complete allergy resolution at each dose of the allergen before increasing the dosage in IFA. Both IFA and NFA can be successfully treated with OIT using IFN-gamma but show different clinical and therapeutic characteristics. IFN-gamma is necessary for the tolerance induction but not for tolerance maintenance. Additional study for the mechanisms of tolerance induction by IFN-gamma is needed.