Is Aboriginal Food Less Allergenic? Comparing IgE-Reactivity of Eggs from Modern and Ancient Chicken Breeds in a Cohort of Allergic Children

Abstract

BackgroundHen's egg allergy ranks among the most frequent primary food allergies in children. We aimed to investigate sensitization profiles of egg allergic patients and compare in vitro IgE reactivities of eggs from ancient chicken breeds (Araucana and Maran) with those from conventional laying hen hybrids.MethodologyEgg allergic children (n = 25) were subjected to skin prick test, double blind placebo controlled food challenge, and sensitization profiles to Gal d 1–5 were determined by allergen microarray. IgE binding and biological activity of eggs from different chicken breeds were investigated by immunoblot, ELISA, and mediator release assays.Principal FindingsWe found that Gal d 1 and Gal d 2 are generally major egg allergens, whereas Gal d 3–5 displayed high sensitization prevalence only in patients reacting to both, egg white and yolk. It seems that the onset of egg allergy is mediated by egg white allergens expanding to yolk sensitization in later stages of disease. Of note, egg white/yolk weight ratios were reduced in eggs from Auraucana and Maran chicken. As determined in IgE immunoblots and mass analysis, eggs from ancient chicken breeds did not differ in their protein composition. Similar IgE-binding was observed for all egg white preparations, while an elevated allergenicity was detected in egg yolk from Araucana chicken.Conclusion/SignificanceOur results on allergenicity and biological activity do not confirm the common assumption that aboriginal food might be less allergenic. Comprehensive diagnosis of egg allergy should distinguish between reactivity to hen's egg white and yolk fractions to avoid unnecessary dietary restrictions to improve life quality of the allergic child and its family.

Relative reactivity to egg white and yolk or change upon heating as markers for baked egg tolerance

“…If reactivity to raw EY was, as generally assumed, lower than to raw EW for most children it was higher for 6 children. They were not older than children with no reactivity to EY as previously suggested . Sensitization to EY mainly involved the plasma EY fraction (LDL or livetins fractions) associated with large sensitizations to EW proteins in agreement with previous studies …”

“…15,26,27 Sensitization to EY mainly involved the plasma EY fraction (LDL or livetins fractions) associated with large sensitizations to EW proteins in agreement with previous studies. 26,28 In current practice, SPT testing with raw EY and EW might allow on an individual basis to identify the patient's pattern of reactivity toward the egg fractions. Care must however be taken relating to potential risk of infection that could be avoided using pasteurized fractions or extracts, provided they are not cross contaminated and correctly standardized.…”

The IgE-microarray testing in atopic dermatitis

“…Different IgE positive results were obtained depending on egg white or yolk recognition. Beside egg allergens, 23 children showed sensitizations to other foods and inhalants confirming that multiple specific IgE evaluation by means of ISAC improves the diagnostic approach in hen's egg allergic children affected by atopic dermatitis [38 ].…”

Screening for hen’s egg and chicken meat specific IgE antibodies in Saudi patients with allergic disorders

“…It was however observed that comparatively higher concentrations of egg white specific IgE antibodies were present in patients who were displaying additional sensitization to egg yolk. 20 This finding indicates an association between egg white and egg yolk specific IgE antibodies. A study investigating food specific IgE antibodies in patients with atopic dermatitis has clearly demonstrated that egg white specific IgE antibodies correlate with egg yolk specific IgE antibodies in these patients.…”