Медицинская иммунология (Jan 2025)
Features of the IgE response to egg white and yolk in children with food allergies and atopic dermatitis
Abstract
Chicken egg is among the most important sources of allergens. Sensitization to them is most often manifests as food allergy (FA), and/or atopic dermatitis (AD). Immunogenic substances of a chicken egg are present in both white egg and yolk.The purpose of our work was to compare frequency and intensity of the IgE responses to various components of a chicken egg in children, depending on their age and gender. We examined 3070 children with symptoms of food allergies and atopic dermatitis, analyzed the IgE responses to chicken white egg allergens extract (f1) and yolk allergens extract (f75), taking into account the age and gender of children. The IgE levels were determined by immunofluorescence using an automatic ImmunoCAP 250 analyzer. We found a high incidence of sensitization to chicken egg in children with FA and AD: 31.07% (n = 954) of patients had clinically significant IgE levels. The frequency of sensitization to white egg was statistically significantly higher than the frequency of sensitization to yolk: 31.04% (n = 953) and 13.13% (n = 403), respectively. The maximum prevalence of positive IgE responses to white egg and yolk and more severe sensitization were observed in children of their first year of life. A significant decrease of these indices has been detected in groups of older children. In older age groups, there was also a decrease in the number of co-sensitized patients, whereas the number of monosensitization cases to chicken egg protein was increased in groups of children of 2 to 6 years old, and then decreased in children over 6 years old. The frequency of positive IgE responses to allergen extracts of white egg and yolk did not differ significantly and had similar age dynamics in children of both sexes. Statistically significant differences between the IgE responses of boys and girls were found only in groups of children over 14 years old, especially with IgE to allergens of white egg. We have shown an extremely low frequency of monosensitization to yolk: clinically significant levels of IgE to yolk in the absence of antibodies to egg protein were found in 0.1% of patients with food allergies and atopic dermatitis. High frequency of sensitization to chicken eggs in small children suggests an extremely early contact of the patients with allergens. The immunogenic ability of white egg and yolk allergens is different. Much more pronounced IgE response was observed towards white egg. A decreasing number of positive IgE response cases to chicken egg allergens in children may be due to development of immunological tolerance to both yolk and white egg at the age of 8-10 years. However, the issue of studying the allergic response mechanisms remains open, since, despite a significant decrease in prevalence of egg allergy in older children, a number of patients still do not achieve tolerance to this food product.
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