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

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.

Conditions

• Food Allergy
• Food Allergy in Infants
• Food Allergy in Children
• Food Allergen Sensitisation
• Milk Allergy
• Egg Allergy
• Nut Allergy

Interventions

DIAGNOSTIC_TEST

Basophil activation test (BAT)

Basophils and mast cells are the key drivers of food allergic reactions and anaphylaxis to foods. The study team have developed new tests that measure the reaction of mast cells and basophils by flow cytometry following stimulation with allergen, the BAT and the MAT: • BAT uses fresh whole blood from patients added to allergen and antibodies in a test tube. The tube containing the allergic cells are then analysed one by one to estimate how many and how much express activation markers on their surface, CD63 and CD203c. MAT uses a human mast cell line (LAD2 cells) which are human mast cells grown in the laboratory to which patients' plasma is added in order to mimic the patients' own mast cells. Sensitised LAD2 cells are then stimulated with allergen or controls and analysed by flow cytometry to assess the expression of the activation marker CD63 on the cell surface, similar to what happens in the BAT. Results of MAT will be considered only in cases of non-responding basophils.

DIAGNOSTIC_TEST

Oral food challenge (OFC)

Consumption of the food suspected of causing an allergic reaction in a medically supervised environment, starting with small amounts and progressively increasing the dose at regular intervals up to a cumulative dose corresponding to an age-appropriate portion of the food.

Sponsors & Collaborators

• Sandwell & West Birmingham Hospitals NHS Trust

  collaborator OTHER

• Cambridge University Hospitals NHS Foundation Trust

  collaborator OTHER

• NHS Lothian

  collaborator OTHER_GOV

• University Hospitals, Leicester

  collaborator OTHER

• Guy's and St Thomas' NHS Foundation Trust

  collaborator OTHER

• University College London Hospitals

  collaborator OTHER

• King's College Hospital NHS Trust

  collaborator OTHER

• Manchester University NHS Foundation Trust

  collaborator OTHER_GOV

• Newcastle-upon-Tyne Hospitals NHS Trust

  collaborator OTHER

• Sheffield Children's NHS Foundation Trust

  collaborator OTHER

• University Hospital Southampton NHS Foundation Trust

  collaborator OTHER

• King's College London

  lead OTHER

Principal Investigators

• Alexandra Santos, MD, PhD · King's College London

Study Design

Allocation

RANDOMIZED

Purpose

DIAGNOSTIC

Masking

TRIPLE

Model

PARALLEL

Eligibility

Min Age

6 Months

Max Age

15 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2023-01-13

Primary Completion

2025-07-31

Completion

2025-07-31

Countries

• United Kingdom

Study Locations