Threshold of Reactivity and Tolerance to Precautionary Allergen-Labelled Biscuits of Baked Milk- and Egg-Allergic Children

Vincenzo Fierro,Stefania Arasi,Rosa Pilolli,Giorgia Bracaglia,Valeria Marzano,Veronica Calandrelli,Linda Monaci,Lamia Dahdah,Lorenza Putignani,Rocco Valluzzi,Pamela Vernocchi,Carla Riccardi,Stefano Levi Mortera,Alessandro Fiocchi,Maurizio Mennini

doi:10.3390/nu13124540

Abstract

Extremely sensitive food-allergic patients may react to very small amounts of allergenic foods. Precautionary allergen labelling (PAL) warns from possible allergenic contaminations. We evaluated by oral food challenge the reactivity to a brand of PAL-labelled milk- and egg-free biscuits of children with severe milk and egg allergy. We explored the ability of proteomic methods to identify minute amounts of milk/egg allergens in such biscuits. Traces of milk and/or egg allergens in biscuits were measured by two different liquid-chromatography-mass spectrometry methods. The binding of patient’s serum with egg/milk proteins was assessed using immunoblotting. None of the patients reacted to biscuits. Egg and milk proteins were undetectable with a limit of detection of 0.6 µg/g for milk and egg (method A), and of 0.1 and 0.3 µg /g for milk and egg, respectively (method B). The immunoblots did not show milk/egg proteins in the studied biscuits. Milk/egg content of the biscuits is far lower than 4 µg of milk or egg protein per gram of product, the minimal doses considered theoretically capable of causing reactions. With high sensitivity, proteomic assessments predict the harmlessness of very small amount of allergens in foods, and can be used to help avoiding unnecessary PAL.

Highlights

The subset of food-allergic patients sensitive to minute amounts of foods is facing problems of food safety every day [1]
As our objective was to verify whether Magretti may be considered technically hypoallergenic for a population of children allergic to baked egg or milk, our sample size was calculated according to the American Academy of Pediatrics (AAP) guidelines for clinical testing of hypoallergenic formulas [22]
Over the four-year period considered, among 379 children confirmed with milk/egg allergy at our hospital, 152 patients were reactive with baked milk/egg

Summary

Introduction

The subset of food-allergic patients sensitive to minute amounts of foods is facing problems of food safety every day [1]. To protect them from accidental ingestions, regulatory authorities have put in place legislative measures prescribing the declaration of food allergen ingredients in the respective food labels [2]. Precautionary labelling of allergens (PAL) has been adopted by food producers as additional level of protection when food allergens may contaminate foods. “information on the possible and unintentional presence in food of substances or products causing allergies or intolerances, provided voluntarily by the food business operator” [3]. PAL may further reduce the possible food choices of consumers who are already forced to reduce their options [4]. PAL-free foods may contain significant amounts of food allergens introduced by contamination at some point in the preparation chain [5]

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