PEAnut Anaphylaxis Predictors

Study Overview
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Brief Summary
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Peanut allergy can be life-threatening. Current diagnostic techniques for peanut allergy have high sensitivity, but not high specificity. This clinical trial will test the validity of a novel blood biomarker (compared with current testing) as a diagnostic predictor of anaphylaxis to peanut.

Detailed Description
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Children aged 2-17 years with suspected peanut allergy will be invited to participate in the study. They will have a questionnaire, a skin prick test to peanut, 2 breathing tests (spirometry and fraction of exhaled nitric oxide (FeNO)), and a blood test (specific peanut antibodies, allergic immune responses - including the novel blood biomarker - and genetic testing to identify novel potential molecular and genetic markers of food allergy in the future. The genetic testing component will be optional). The breathing test is not required for those under 6 years. The final step is an open label peanut food challenge with incremental doses of peanut, (routine practise) as per the Australasian Society of Clinical Immunology and Allergy (ASCIA) food challenge protocol.The endpoints in the food challenge will be signs of allergy or anaphylaxis as per PRACTicing ALLergology (PRACTALL) consensus report for oral food challenges OR completion of the ASCIA food challenge protocol. Outcome: The primary outcome of the project is to confirm that a novel blood biomarker has a higher diagnostic accuracy as compared to current best testing in predicting anaphylaxis at open label peanut challenge. Secondary outcome: Will be to determine the value of the biomarker, FeNO and Ara h2 specific Immunoglobulin E (sIgE) (individually and in combination) at predicting anaphylaxis or clinical allergy at open label peanut challenge.

Official Title
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PEAnut Anaphylaxis Predictors

Conditions
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Peanut Hypersensitivity, Anaphylaxis

Intervention / Treatment
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* Other: Questionnaire
* Other: Peanut Skin prick test
* Other: Fraction of exhaled nitric oxide
* Other: Spirometry
* Other: Serum Peanut and Ara h2 specific immunoglobulin E
* Other: Collection of blood biomarker
* Other: Peanut food challenge


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Children aged 2 - 17 years with an allergy to peanut and require peanut challenge to confirm peanut allergy. Exclusion Criteria: Children with Peanut Skin Prick Test (SPT) wheal size greater than 10mm as these children are likely to have clinical peanut allergy (no clinical indication for food challenge).

Ages Eligible for Study
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Minimum Age: 2 Years
Maximum Age: 17 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Entire group<br>Children aged 2-17 years with suspected peanut allergy who require peanut food challenge to confirm clinical allergy, will be recruited for the study. They will undergo a preceding questionnaire, peanut skin prick testing, spirometry, fraction of exhaled nitric oxide (FeNO) measurement, serum peanut and Ara h2 specific immunoglobulin E (sIgE) antibodies, and collection of blood biomarker prior to food challenge. The primary endpoint will be anaphylaxis at open label peanut challenge, with the primary exposure of interest will be the serum biomarker. | Other: Questionnaire<br>* 5 minute questionnaire focused on symptoms of allergic disease<br>Other: Peanut Skin prick test<br>* Skin prick testing with peanut antigen, according to ASCIA Skin Prick testing manual<br>Other: Fraction of exhaled nitric oxide<br>* Measurement of exhaled nitric oxide, according to American Thoracic Society/ European Thoracic Society (ATS/ERS) standardised procedures (Not required for those age less than 6 years).<br>Other: Spirometry<br>* Measurement of lung flows/volumes, according to ATS/ERS standardised procedures (Not required for those age less than 6 years).<br>Other: Serum Peanut and Ara h2 specific immunoglobulin E<br>* Peanut and Ara h2 specific IgE antibodies<br>Other: Collection of blood biomarker<br>* Correlation of blood biomarker levels in patients with successful or unsuccessful peanut food challenge<br>Other: Peanut food challenge<br>* Open label peanut challenge conducted according to ASCIA's peanut challenge protocol and PRACTALL consensus report<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Blood biomarker predicting anaphylaxis at peanut food challenge | The primary outcome of the project is to confirm that a novel blood biomarker has a higher diagnostic accuracy as compared to current best testing in predicting anaphylaxis at open label peanut challenge. | At completion of peanut food challenge | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Blood biomarker in combination with FeNO, and/or Ara h2 sIgE predicting anaphylaxis at peanut food challenge | The secondary outcome will be to determine the value of the biomarker, FeNO and Ara h2 sIgE (individually and in combination) at predicting anaphylaxis or clinical allergy at open label peanut challenge. | At completion of peanut food challenge |