Respiratory allergy to lipid transfer protein

Due to unclear reasons, allergy to lipid transfer protein (LTP) is frequent in Mediterranean countries but rare in Northern Europe.

We report a paradigmatic case of primarily airborne sensitization to LTP that might explain the geographical distribution of this type of food allergy.

A 21-year-old woman began having severe perennial rhinitis 6 months after she started working in a wholesale fruit storehouse in Southern Italy where large amounts of fruits, including peaches, were handled; symptoms subsided when she left the workplace for >5 days and relapsed as soon as she was back at work. Later on, she developed severe food allergies to peach, hazelnut, peanut, apricot, plum and tomato. The patient underwent a nasal challenge with peach peel extract, and IgE reactivity was assessed by immunoblot analysis.

In vivo and in vitro analyses showed sensitivity to LTP. The nasal challenge with peach peel extract (6 microg protein) induced acute, severe respiratory symptoms. On immunoblot with peach peel extract patient's serum reacted uniquely against LTP, as demonstrated by inhibition assays with the recombinant peach protein.

LTP may induce sensitization via the respiratory tract due to inhalation of air-dispersed food particles, and this may precede the onset of food allergy. If this way of sensitization were effective in the majority of LTP allergic patients (e.g. by exposure to peaches showing intact fuzz in areas where peaches are grown and directly sold on the market) our findings could explain the strange geographical distribution of this type of food allergy.