Basophile Activation Testing (BAT) in Hazelnut Allergy (Hazelnut BAT Study)

Study Overview
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Brief Summary
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The proposed study intends to compare the outcome of food challenge in hazelnut allergic patients with the outcome of basophile activation tests using hazelnut extract and components.

Detailed Description
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Accurate diagnosis of food allergy depends on food challenge outcome. The proposed study intends to compare the outcome of food challenge in hazelnut allergic patients with the outcome of basophile activation tests using hazelnut extract and components to evaluate the diagnostic utility of basophile activation testing. With a view towards improved in vitro diagnostic methods, the investigators intend to evaluate the diagnostic potential of basophile activation testing in patients with hazelnut allergy confirmed by a positive provocation or supported by a convincing history of anaphylactic reaction(s) to hazelnut in the past, patients with pollinosis but no symptoms of hazelnut allergy and non-atopic control subjects.

Official Title
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Correlation of the in Vivo Food Provocation Test With the in Vitro Basophile Activation Test in Hazelnut Allergic Patients

Conditions
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Food Allergy

Intervention / Treatment
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* Diagnostic Test: Food challenge
* Diagnostic Test: skin testing
* Diagnostic Test: blood sampling


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Primary Inclusion criteria: Male and female subjects, age ≥ 14 years Informed Consent as documented by signature Secondary inclusion criterion Group A: positive case history of allergic reaction(s) to hazelnut positive double-blind placebo-controlled food challenge with hazelnut or positive titrated open food challenge with hazelnut or unambiguous case history of an anaphylactic reaction after hazelnut will be included without provocation Group B:positive skin test (SPT) with birch pollen and hazelnut and negative food provocation with hazelnut. Group C: negative case history of hazelnut and birch allergy and negative skin test (SPT) with hazelnut and birch pollen and negative food provocation with hazelnut Exclusion Criteria: Drugs not allowed due to interference with the food challenge (or shortest interval between last treatment and food challenge): corticosteroids systemically (2 weeks), antihistamines (3 days), beta blocker (1 day), angiotensin converting enzyme (ACE) inhibitors (2 days), omalizumab (2 months) Women who are pregnant Lack of safe contraception Uncontrolled asthma, forced expiratory volume (1 second) <70% predicted value Acute allergic disease Chronic urticaria Mastocytosis Other clinically significant concomitant disease states Known or suspected non-compliance, drug or alcohol abuse, Inability to follow the procedures of the study Participation in another study with investigational drug within the 30 days preceding and during the present study

Ages Eligible for Study
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Minimum Age: 14 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

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
Interventional Model Description: The study intends to compare the outcome of food challenge with hazelnut and the in vitro basophile activation test using hazelnut extract and allergens
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Hazelnut allergy<br>patients with positive case history of hazelnut allergy and a positive skin testing are undergoing a food challenge and blood sampling for basophile activation testing | Diagnostic Test: Food challenge<br>* food challenge with hazelnut<br>Diagnostic Test: skin testing<br>* Skin testing with hazelnut extract<br>Diagnostic Test: blood sampling<br>* blood sampling to perform basophile activation tests<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of patients with challenge confirmed food allergy to hazelnut and a positive basophile activation test | outcome of food challenge in hazelnut allergic patients will be compared to the outcome of basophile activation using hazelnut extract and allergens | up to 3 years | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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hazelnut, allergens, basophile-activation-test, food, allergy