Peanut allergy is one of the most serious food allergies because of its life long persistence, and the potential for severe allergic reactions. Effective oral immunotherapy would benefit patients by reducing the likelihood that they will have life-threatening accidental allergic reactions. This research study is being done to develop an effective oral immunotherapy treatment for patients with peanut allergy.

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:

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

Inclusion criteria:

1. 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
2. Ability to provide informed consent.
3. Males and females of all ethnic/racial groups between 7 and 21 years who are otherwise healthy.

Exclusion criteria:

1. 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
2. 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/)
3. 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/)
4. Diagnosis of other severe or complicating medical problems
5. Autoimmune or chronic immune or gastrointestinal inflammatory conditions, including Celiac Disease, Inflammatory Bowel Disease and Eosinophilic Gastrointestinal Disorders
6. Primary Immune Deficiency
7. Use of beta blockers, angiotension converting enzyme inhibitors, or monoamine oxidase inhibitors
8. Women of childbearing potential who are pregnant, planning to become pregnant, or breastfeeding
9. Use within the past year of other systemic immunomodulatory treatment, including allergen immunotherapy, use of biologics with an immune target, including Xolair

From Oct 2011 to July 2014

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