Double-blind, placebo-controlled food challenge with apple

Area of Science:

• Allergy and Immunology
• Food Science
• Clinical Diagnostics

Background:

• Apple allergy is common in individuals with birch pollen allergy.
• Accurate diagnostic methods are crucial for managing food allergies.
• Double-blind, placebo-controlled food challenges (DBPCFC) are the gold standard for diagnosing food allergies.

Purpose of the Study:

• To develop and evaluate different DBPCFC methods for apple allergy.
• To compare the sensitivity and reliability of fresh apple juice, grated apple, and freeze-dried apple powder.
• To characterize freeze-dried apple material for allergy testing.

Main Methods:

• Three DBPCFC models were tested: apple juice, grated apple, and freeze-dried apple powder.
• Challenges were conducted in birch pollen-allergic patients with a history of apple allergy.
• Freeze-dried apple material was analyzed using leukocyte histamine release (HR), skin prick tests (SPT), and immunoblotting.

Main Results:

• DBPCFC with apple is feasible in birch pollen-allergic individuals.
• Fresh apple juice model showed low sensitivity and high placebo reaction rate.
• Grated apple and freeze-dried apple powder models had sensitivities of 0.74 and 0.60, respectively.

Conclusions:

• Freeze-dried apple powder is a viable option for DBPCFC, SPT, and HR testing.
• Further research is needed on the stability and allergenic profile of freeze-dried apple powder.
• Improved sensitivity in DBPCFC models for apple allergy is desirable.