Lipid transfer proteins and allergy to oranges

Area of Science:

• Allergen research
• Food allergy
• Immunology

Background:

• Lipid transfer proteins (LTPs) are significant fruit allergens and proposed model plant food allergens.
• No citrus fruit allergens had been characterized prior to this study.
• This research aimed to identify and isolate citrus fruit LTPs and assess their role in orange allergy.

Purpose of the Study:

• To identify and isolate lipid transfer proteins (LTPs) from citrus fruits.
• To investigate the relevance of these citrus LTPs in patients with orange allergy.
• To analyze cross-reactivity between citrus LTPs and other known LTP allergens.

Main Methods:

• Selected 27 patients with oral allergy syndrome to oranges and positive allergy tests.
• Isolated natural orange (nCit s 3) and lemon (nCit l 3) LTPs and a recombinant orange LTP (rCit s 3).
• Characterized allergens using N-terminal sequencing, mass spectrometry, and IgE testing, including cross-reactivity assays with Pru p 3.

Main Results:

• Natural and recombinant citrus LTPs (nCit s 3, nCit l 3, rCit s 3) were isolated and characterized.
• Specific IgE to citrus LTPs was detected in 46-54% of patients.
• Cross-reactivity was observed between orange, lemon, and peach LTPs (Pru p 3).

Conclusions:

• Lipid transfer proteins (LTPs) are implicated in orange allergy, eliciting reactions in 30-50% of studied patients.
• Both orange and lemon LTPs demonstrate cross-reactivity with the major peach allergen, Pru p 3.
• These findings highlight the importance of LTPs in citrus fruit allergies and potential cross-reactivity.