The Clinical Impact of the Basophil Activation Test to Diagnose Food Allergy

Not Applicable

Recruiting

• Conditions: Food Allergy in Children; Food Allergy in Infants; Food Allergen Sensitisation; Food Allergy; Milk Allergy; Egg Allergy; Nut Allergy
• Interventions: Diagnostic Test: Basophil activation test (BAT); Diagnostic Test: Oral food challenge (OFC)

• Registration Number: NCT05309772
• Lead Sponsor: King's College London

Brief Summary

The BAT Impact study is a prospective multicentre study in the UK using a biomarker-led study design to compare the incidence of adverse events (defined as allergic reactions during oral food challenges) in a randomized-controlled trial. Patients will either follow the standard-of-care (i.e. an oral food challenge in case of equivocal SPT/sIgE) or follow a basophil activation test (BAT)/mast cell activation test (MAT)-based strategy, i.e. patients with a positive BAT or MAT are dispensed of an oral food challenge (OFC) and patients with a negative BAT/MAT undergo an OFC.

Detailed Description

Children aged 6 months to 15 years requiring an oral food challenge to one of the study foods (milk, egg, peanut, sesame or cashew nut) will be invited to participate in the study.

Eleven centres across the UK will be recruiting participants and perforning clinical procedures, such as skin prick testing and oral food challenges (OFC), as per standard clinical care.

Participants will be randomised 4:5 to either have the standard-of-care, i.e. oral food challenge to the suspected food, or take BAT (MAT if BAT inconclusive) into account to decide whether or not OFC will be required: if BAT/MAT is positive, food allergy will be confirmed without doing OFC; if BAT/MAT is negative, participants in the biomarker arm will undergo OFC.

The primary outcome is the proportion of positive OFC in the biomarker arm compared with the standard-of-care arm.

Secondary outcomes are: number of OFC, quality of life, anxiety and costs associated with the diagnostic work-up.

Study Timeline

• Study First Submitted: 2021-09-07
• Study First Submitted QC: 2022-03-24
• Study First Posted: 2022-04-04
• Study Start: 2023-01-13
• Status Verified: 2023-03
• Last Update Submitted: 2023-09-05
• Last Update Posted: 2023-09-06
• Primary Completion: 2025-07
• Study Completion: 2025-07

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 398

Inclusion Criteria

• Children and young people aged 6 months to 15 years

• Suspected allergy to one of the study foods (peanut, cow's milk, egg, cashew, sesame) - defined as:

  • history of clinical reaction or
  • evidence of IgE sensitisation (SPT>0mm and/or specific IgE>=0.10 KU/L) to the respective food or
  • reassessment for possible resolution of allergy to the specific food following previous diagnosis of food allergy

• Need for an oral food challengeOFC to the study food

• Oral food challengeOFC to reach amount of food protein in a typical portion size for child's age

• Consent from adults with parental responsibility and assent from children and young people in an age appropriate form.

Exclusion Criteria

• Clinically significant chronic illness other than atopic diseases;

• Previous history of severe life-threatening reaction to the suspected food with documented decrease in oxygen saturation (<90%), hypotension (≥20% reduction in systolic blood pressure) and/or admission to intensive care;

• Unwillingness to comply with study procedures, namely to undergo a diagnostic food challenge;

• Contra-indication for diagnostic food challenge, namely:

  • Uncontrolled atopic diseases (e.g. eczema, asthma, rhinitis);
  • Chronic medical conditions that pose significant risk in the event of anaphylaxis or treatment of anaphylaxis (e.g. cardiac disease, severe lung disease, pregnancy, mastocytosis);
  • Inability to discontinue medications that might interfere with assessment or safety (e.g. antihistamines, β-agonists, β-blockers, NSAIDs, ACE inhibitor, antacids);
  • Recent (within 7-14 days) treatment with systemic steroids or prolonged high-dose systemic steroids or immunosuppressants;

• Undergoing treatment with omalizumab, food or inhalant allergen immunotherapy or other systemic immunomodulatory treatment;

• Inability to stop anti-histamines prior to SPT or OFC.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Biomarker arm	Oral food challenge (OFC)	All participants will have blood taken to test for BAT/MAT. Participants with a positive BAT/MAT will dispense from oral food challenge (OFC). Participants with negative or inconclusive BAT/MAT will undergo OFC.
Biomarker arm	Basophil activation test (BAT)	All participants will have blood taken to test for BAT/MAT. Participants with a positive BAT/MAT will dispense from oral food challenge (OFC). Participants with negative or inconclusive BAT/MAT will undergo OFC.
Standard-of-care arm	Basophil activation test (BAT)	All participants in the standard-of-care arm will have blood taken to test for BAT/MAT. Regardless of the result of BAT/MAT, all participants in this arm will undergo an oral food challenge, as per the current standard-of-care.
Standard-of-care arm	Oral food challenge (OFC)	All participants in the standard-of-care arm will have blood taken to test for BAT/MAT. Regardless of the result of BAT/MAT, all participants in this arm will undergo an oral food challenge, as per the current standard-of-care.

Primary Outcome Measures

Name	Time	Method
The proportion of positive oral food challenges in the biomarker arm (BAT ± MAT) compared to the standard-of-care arm	Up to 1 year	Comparison of the ratio of positive oral food challenges in the biomarker arm compared to the standard-of-care arm.
Number of OFCs in the biomarker arm (BAT ± MAT) compared to the standard-of-care arm	Up to 1 year	Comparison of the ratio of OFCs in the biomarker arm compared to the standard-of-care arm.

Secondary Outcome Measures

Name	Time	Method
Anxiety levels of parents and children before and after diagnostic work-up as assessed by the State Trait Anxiety Inventory.	Up to 1.5 years	Change in anxiety score before and after diagnostic work-up.
The quality of life of children and parents at the start and at the end of the diagnostic work-up for food allergy as assessed by the Food Allergy Quality of Life Questionnaire.	Up to 1.5 years	Change in quality of life score at the start and end of diagnostic work-up.
Anxiety levels of parents and children before and after diagnostic work-up as assessed by the Hospital Anxiety and Depression Questionnaire.	Up to 1.5 years	Change in anxiety score before and after diagnostic work-up.
NHS and societal costs of food allergies during the diagnostic assessment, as measured through a bespoke form.	Up to 1.5 years	NHS and societal costs during the six weeks before and six weeks after diagnostic work-up.

Trial Locations

Locations (11)

Royal Manchester Children's Hospital; 🇬🇧 Manchester, United Kingdom

University College London Hospital; 🇬🇧 London, United Kingdom

Evelina London Children's Hospital; 🇬🇧 London, United Kingdom

Sandwell and West Birmingham Hospital; 🇬🇧 Birmingham, United Kingdom

Leicester Royal Infirmary; 🇬🇧 Leicester, United Kingdom

King's College Hospital; 🇬🇧 London, United Kingdom

Addenbrookes Hospital; 🇬🇧 Cambridge, United Kingdom

Royal Hospital for Children and Young People; 🇬🇧 Edinburgh, United Kingdom

Great North Children's Hospital; 🇬🇧 Newcastle, United Kingdom

University Hospital Southampton; 🇬🇧 Southampton, United Kingdom

Sheffield Children's Hospital; 🇬🇧 Sheffield, United Kingdom