Currently, when a food allergy is diagnosed, the "standard of care" is strict avoidance of the allergic food and ready access to self-injectable epinephrine. Yet, accidental ingestions do occur. Unfortunately, for a ubiquitous food such as peanut, the possibility of an inadvertent ingestion is great. It is estimated that over 50% of individuals who are allergic to peanuts will have an accidental reaction to peanuts over a 2-year period. The purpose of this study is to determine if peanut sublingual immunotherapy (SLIT) reduces the number and/or symptoms of accidental peanut ingestion in peanut allergic subjects. We would anticipate that the subjects on the peanut SLIT protocol would experience few adverse effects with accidental peanut ingestion over the course of the two years of SLIT. The primary endpoint to evaluate the effectiveness of SLIT will be a negative DBPCFC to peanuts (8 grams) at the completion of the two years of the study.

Peanut allergy is one of the most serious of the immediate hypersensitivity reactions to foods in terms of persistence and severity of the reaction and appears to be a growing problem. Allergen-specific immunotherapy (IT) is currently being examined as a treatment option because of the persistence of this hypersensitivity reaction and the lack of effective treatment. An understanding of the molecular mechanisms of peanut-specific IT is vital to ensure the eventual, successful treatment of peanut-allergic patients.

The goal of this proposal is to develop peanut immunotherapy (IT) for patients with peanut allergic reactions. This innovative application is designed to utilize the extensive knowledge of the allergens involved in peanut hypersensitivity to devise an immunotherapeutic approach that would lower the risk of anaphylactic reactions and would down regulate peanut-specific T cells in peanut-allergic patients. Previous attempts to utilize peanut-specific immunotherapy have been unsuccessful primarily because of the severe side effects of therapy.

The specific aim of the study is to desensitize/tolerize peanut-allergic subjects with peanut allergen-specific, sublingual immunotherapy (SLIT) and begin to determine the molecular mechanism of the peanut-specific T-cell response during SLIT.

The hypothesis is that peanut SLIT will desensitize patients with peanut allergic reactions by the induction of peanut specific regulatory T cells resulting in immune modulation of the peanut allergic reaction.

Inclusion Criteria:

• Subjects between 6 and 35 years of age
• Diagnosed with peanut allergy by positive prick skin test, CAP FEIA of 15 Ku/L or greater
• History of significant clinical symptoms within one hour after ingestion of peanuts
• Family's compliance with all study visits

Exclusion Criteria:

• Subjects with medical history preventing a BDPCFC to peanut
• Subjects unable to cooperate with challenge procedure
• Subjects unable to be reached by telephone for follow-up
• Subjects with a history of severe anaphylaxis to peanut