Food Allergy
Conditions
Brief summary
The investigators will conduct low-dose intranasal allergen challenges on children and young people with an indeterminate diagnosis of food allergy to cow's milk or peanut. Blood samples will also be taken, for conventional blood allergy diagnostics (allergy-specific Immunoglobulin E) and mast cell activation test (MAT). The data will be used to determine the diagnostic accuracy of two complementary, novel approaches to diagnose food allergy, in a representative clinical cohort.
Interventions
DIAGNOSTIC_TESTIntranasal food challenge
Subjects will undergo an incremental intranasal challenge to initially 0.9% NaCl saline solution, and then increasing doses of the food protein
DIAGNOSTIC_TESTMast cell activation test
Blood will be processed for mast cell activation as previously described (https://doi.org/10.1016/j.jaci.2018.01.043)
Sponsors
Royal College of Surgeons, Ireland
University of Manchester
Imperial College London
Study design
Allocation
NON_RANDOMIZED
Intervention model
SINGLE_GROUP
Primary purpose
DIAGNOSTIC
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
2 Years to 18 Years
Healthy volunteers
No
Inclusion criteria
* IgE-sensitisation to peanut, (hen's) egg or cow's milk, with indeterminate clinical (allergy) status, defined as IgE-sensitisation below 95% positive predictive value (PPV) for diagnosis for either allergen-specific IgE or SPT, using published cut-offs OR clinician suspicion of tolerance (on basis of clinical history) despite IgE sensitisation \>95% PPV cut-offs. * Written informed consent from parent/guardian, with assent from children aged 6 years and above wherever possible. Participants aged over 16 years will need to provide their own informed consent.
Exclusion criteria
* Acute illness or current unstable asthma, defined as: 1. Febrile ≥38.0oC in last 72 hours 2. Acute wheeze in last 72 hours requiring treatment 3. Recent admission to hospital in preceding 2 weeks for acute asthma * Current medication 1. Asthma reliever medication required in preceding 72 hours 2. Recent administration of a medicine containing antihistamine within the last 3 days 3. Current oral steroid for asthma exacerbation or course completed within last 2 weeks * Unwilling or unable to fulfil study requirements
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Test performance | 1 day | Comparison of test performance characteristics (sensitivity, specificity, measured according to standard statistical methods) for each of the following diagnostic tests, compared to a formal oral food challenge (FC) as the reference standard: i. Intranasal FC (InFC) ii. Skin prick testing iii. Characterisation of serum-specific IgE to whole allergen, components and molecular components iv. Mast cell activation test (MAT) v. Basophil activation test (BAT) (peanut only) |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Adverse events | 1 day | Number of participants who experience a non-allergic adverse event, and/or have symptoms of a systemic allergic reaction) associated with the intranasal food challenge. |
Countries
Ireland, United Kingdom
Outcome results
None listed