Oral Peanut Immunotherapy

Our hypothesis is that chronic antigen exposure during peanut oral immunotherapy (OIT) will induce beneficial changes in the specific immune response, including: 1) anergy of IgE effector immune cells (e.g., mast cells, basophils) resulting in clinical desensitization; 2) induction of de novo, long lived (memory) B cell responses that antagonize specific IgE and confer immune tolerance. The investigators will test this hypothesis in the following specific aims:

• Induce desensitization in peanut allergic subjects with peanut OIT and evaluate the safety of the peanut OIT desensitization protocol.
• Induce long-standing tolerance in peanut allergic subjects with maintenance peanut OIT and evaluate the efficacy of allergen-specific testing to predict tolerance.
• Longitudinally evaluate basophil and mast cell reactivity in subjects receiving peanut OIT and their relationship to the induction of desensitization.
• Longitudinally evaluate the allergen-specific B-cell repertoire in subjects receiving peanut OIT and its relationship to the induction of tolerance.

Inclusion criteria

• Diagnosis of peanut allergy by a positive prick skin test to peanut (> 8 mm reaction wheal) or CAP FEIA >10 and a history of objective clinical symptoms within one hour after ingestion of peanuts
• Ability to provide informed consent.
• Males and females of all ethnic/racial groups between 7 and 21 years who are otherwise healthy.

Exclusion criteria

• Clinical history of a severe anaphylactic reaction known or suspected to be caused by ingestion of peanut that required treatment with 2 or more administrations of epinephrine or hospitalization
• Moderate to Severe Asthma as defined using the Impairment or Risk Criteria of the current NHBLI Guidelines for the Diagnosis and Management of Asthma (http://www.nhlbi.nih.gov/guidelines/asthma/)
• Poorly controlled Asthma as defined using the Control Criteria of the current NHBLI Guidelines for the Diagnosis and Management of Asthma (http://www.nhlbi.nih.gov/guidelines/asthma/)
• Diagnosis of other severe or complicating medical problems
• Autoimmune or chronic immune or gastrointestinal inflammatory conditions, including Celiac Disease, Inflammatory Bowel Disease and Eosinophilic Gastrointestinal Disorders
• Primary Immune Deficiency
• Use of beta blockers, angiotension converting enzyme inhibitors, or monoamine oxidase inhibitors
• Women of childbearing potential who are pregnant, planning to become pregnant, or breastfeeding
• Use within the past year of other systemic immunomodulatory treatment, including allergen immunotherapy, use of biologics with an immune target, including Xolair