Evaluation of Allergenicity of Hypoallergenic Peanut Product in Peanut Allergic Subjects

This is a proof of concept study to determine the safety and allergenicity of hypoallergenic peanut product extract as compared to standard peanut extract in an adult population with known peanut allergy. This will be assessed by epicutaneous skin prick testing. The hypothesis is that subjects with previously diagnosed peanut allergy will have less epicutaneous reactions to the hypoallergenic peanut product extract.

Peanut allergic volunteers will be identified by positive skin prick test to peanut (peanut extract obtained from Greer laboratories). The peanut extract to be used is FDA approved and is routinely used in confirming a diagnosis of peanut allergy. Serum Total IgE and peanut-specific IgE will be measured for assessment of atopy in general and confirmation of Peanut allergy respectively. Only patients with positive skin test to peanut will enrolled into the study. Allergic volunteers will be asked to abstain from taking any antihistamines (H1 or H2) during the 3 days prior to the skin testing. Testing day 1. Obtain informed consent 2. Obtain medical history, list of current medications 3. Vital signs. 4. Obtain urine pregnancy test if applicable 5. Perform partial physical exam (PE) to include, ENT, Eyes, Neck, Respiratory, Cardiac and Skin with focus mainly on lungs to rule out bronchospasm/asthma exacerbation. 6. Epicutaneous skin prick testing with histamine and saline control, standard peanut extract will be done on all subjects (Total skin prick=3). Those subjects who qualify for the study (test positive to standard peanut extract) will then undergo skin prick testing with standard histamine control, standard saline control, hypoallergenic (Trypsin+Chymotrypsin treated) extract, extract from blanched untreated (no enzyme) peanuts, non-blanched untreated extracts, and peanuts treated with 0.2% inactivated a-chymotrypsin and trypsin as an enzyme control. A second set of skin testing reagents may used these reagents have been treated with alcalase. Skin testing will be read at 15 minutes. A positive test is defined as ≥ 3mm wheal compared to saline control. DermaPIK device will be used for this skin prick testing. 7. Obtain blood samples One time 20ml collection for determination of total IgE, peanut specific IgE in peanut allergic individuals only. Physical Exams will be performed by a study physician. Procedures such as skin testing, vital signs, venipuncture, will be done by a study coordinator, qualified nurse or technical staff. Clinical labs (Serum IgE and Peanut-specific IgE) will be processed at Labcorp Inc in Burlington, NC. Recording of Skin Test results: Skin test reactions will be traced onto clear cellophane tape from which measurements will be obtained. This tape will be affixed to a subject's visit record but not their personal medical record. Excess samples remaining after completion of analyses for this study will be stored in the CEMALB Repository (IRB #05-2528) and all participants will be asked to sign the Repository consent form. Failure to consent to the repository will not result in exclusion from the main study.