Basophil Activation Test to Diagnose Food Allergy

Food Allergy Clinical Trial

— BAT2  

Official title:

Basophil Activation Test to Diagnose Food Allergy

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT03309488
• Other study ID #: IRAS 197886
• Status: Recruiting
• Start date: January 30, 2018
• Est. completion date: July 31, 2021

Study information

• Verified date: September 2020
• Source: King's College London
• Contact: Alexandra Santos, MD PhD
• Phone: +442071886424
• Email: alexandra.santos[@]kcl.ac.uk
• Is FDA regulated: No
• Study type: Observational

Clinical Trial Summary

The BAT II Study is a cross-sectional diagnostic study in which children with suspected IgE-mediated allergy to foods (namely cow's milk, egg, sesame and cashew), as defined by a history of an immediate-type allergic reaction to a food or no history of food consumption or the presence of food-specific IgE as documented by skin prick test or serum specific IgE, will undergo a diagnostic work-up to confirm or refute the diagnosis of IgE-mediated food allergy. Participants will be prospectively recruited from specialised Paediatric Allergy clinics in London and will undergo skin prick testing (SPT), specific IgE testing to allergen extracts and allergen components, basophil activation test (BAT) and oral food challenge. The diagnostic accuracy of the BAT and of other allergy tests will be assessed against the clinical gold-standard.

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 600
• Est. completion date: July 31, 2021
• Est. primary completion date: July 31, 2021
• Accepts healthy volunteers: No
• Gender: All
• Age group: 6 Months to 16 Years

Eligibility

Inclusion Criteria:

1. Children =6 months and <16 years old;

2. Suspected IgE-mediated food allergy defined by:

• History of an immediate-type allergic reaction to a specific food or

• No history of consumption of the specific food or

• IgE sensitisation documented by skin prick test (=1 mm) or serum specific IgE (=0.10 KU/L);

3. Avoidance of the specific food for at least 2 days prior to blood collection for BAT and specific IgE and prior to the challenge;

4. Informed consent obtained from parent or guardian and assent obtained from the child.

Exclusion Criteria:

1. Clinically significant chronic illness other than atopic diseases;

2. 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;

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

4. 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, ß-agonists, ß-blockers, NSAIDs, ACE inhibitor, antacids);

• Recent (within 7-14 days) treatment with systemic steroids or prolonged high-dose systemic steroids or immunosuppressants;

5. Undergoing treatment with omalizumab, food allergen immunotherapy or other systemic immunomodulatory treatment;

6. Inability to stop anti-histamines prior to SPT.

Related Conditions & MeSH terms

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

Intervention

Diagnostic Test:
• Oral food challenge
Patients with suspected food allergy will undergo clinical and dietary assessments and oral food challenge. Different allergy tests will be performed, including skin prick test, specific IgE test and basophil activation test, and its diagnostic utility will be determined against the clinical gold-standard.

Locations

Country	Name	City	State
United Kingdom	Pediatric Allergy Clinical Research Facility, Evelina Children's Hospital	London

Sponsors (2)

Lead Sponsor	Collaborator
King's College London	Guy's and St Thomas' NHS Foundation Trust

Country where clinical trial is conducted

United Kingdom, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Diagnostic accuracy of the basophil activation test (for each individual food allergy)	Accuracy of %CD63+ basophils	3 years
Secondary	Diagnostic accuracy of SPT, specific IgE to extracts and to single allergens	Accuracy of weal diameter or level of IgE	3 years
Secondary	Association between BAT and severity of symptoms during challenges	Correlation between %CD63+ basophils and severity grade	3 years
Secondary	Association between BAT and threshold of reactivity during challenges	Correlation between CD-sens and cumulative threshold dose	3 years