Evaluation of Allergenicity of Hypoallergenic Peanut Product in Peanut Allergic Subjects
Condition: Peanut Allergy
MeSH terms: Peanut Hypersensitivity
Study type: Observational

Summary: 
      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.
    

Detailed description: 
      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.
    

Intervention name(s): Epicutaneous skin prick testing
Intervention type(s): Other
Intervention description(s): Epicutaneous skin prick testing will be performed utilizing the following extracts:
Histamine control purchased from Greer.
Saline control purchased from Greer.
Standard Peanut Extract purchased from Greer.
Sterile extract prepared from Trypsin and Chymotrypsin treated peanuts. This is prepared by North Carolina A & T.
Sterile extract prepared from roasted & blanched but untreated peanuts. This is prepared by North Carolina A & T.
Sterile extract prepared from peanuts (no blanching, no enzyme). This is prepared by North Carolina A & T. This is not classified as a drug and is
Sterile extract containing peanuts treated with 0.2% inactivated a-chymotrypsin and trypsin as an enzyme negative control.
Sterile extracts containing peanuts that have been treated with alcalase
Time perspective: Prospective
Sampling method: Probability Sample
Study population: 
        Thirty (30) adult subjects with history of peanut allergy, with or without asthma will be
        recruited. All participants will be adults ages 18-65. There will no gender or ethnic
        restrictions.
      
Biospecimen description: 
      Venipuncture for 30mL of blood taken for measurement of peanut IgE.
    
Keywords: peanut allergy; hypoallergenic peanut extracts; epicutaneous skin prick testing