A novel immunoassay using recombinant allergens simplifies peanut allergy diagnosis

Area of Science:

• Immunology
• Allergy Diagnostics
• Clinical Chemistry

Background:

• Double-blind placebo-controlled food challenge (DBPCFC) is the gold standard for peanut allergy diagnosis but requires hospitalization and carries risks of severe reactions.
• There is a need for simpler, safer diagnostic methods for peanut allergy, especially for pediatric patients.
• This study aimed to evaluate the diagnostic performance of novel in vitro blood tests for peanut allergy.

Purpose of the Study:

• To assess the diagnostic accuracy of a new set of in vitro blood tests for peanut allergy.
• To compare the performance of these blood tests against the established gold standard (DBPCFC).

Main Methods:

• Measured IgE levels against peanut extract and recombinant peanut allergens (Ara h 1, 2, 3, 6, 7, 8) in three patient groups.
• Patient groups included those with confirmed peanut allergy (n=166), pollen-sensitized individuals without peanut allergy (n=61), and healthy controls (n=10).
• Data collected from two independent clinical centers.

Main Results:

• A significant portion (79%) of pollen-sensitized patients without peanut allergy showed IgE binding to peanut.
• Combining specific IgE tests for peanut extract and recombinant Ara h 2 and Ara h 6 achieved 98% sensitivity and 85% specificity at a 0.10 kU/l threshold.
• Increasing the threshold for Ara h 2 to 0.23 kU/l improved specificity to 96% but reduced sensitivity to 93%.

Conclusions:

• A simple blood test demonstrates high precision for diagnosing peanut allergy.
• This in vitro diagnostic approach offers a safer and more accessible alternative to DBPCFC.
• DBPCFC remains valuable for complex cases with conflicting immunological and clinical findings.