Fecal zonulin as a prognostic marker of atopic march in children with food allergy

Introduction. The onset of allergic diseases most often occurs in early childhood with the onset of food allergies, which can subsequently lead to the implementation of the atopic march. Increased intestinal permeability with high production of zonulin, the main moderator of intestinal tight junctions, can be an important link in the development of comorbid allergic diseases. Material and methods. In order to study the significance of fecal zonulin as a marker for predicting the atopic march in children with food allergy, a cross-sectional retrospective study was conducted on 73 children aged 5 years who were diagnosed with food allergy (FA) to cow’s milk proteins in the first year of life. In all children, when the diagnosis was made in the first year of life, the content of zonulin in feces was determined using the ELISA method. Results. As a result of dynamic observation, all children with food allergy were divided into 2 groups: the first group consisted of children with food allergy who developed allergic rhinitis and/or bronchial asthma within 5 years (group I, n = 39), group 2 consisted of 34 children with food allergy who did not implement the atopic march within 5 years of observation (group II, n = 34). Our study showed statistically significant differences in the fecal zonulin level in the first year of life: group I Me = 2.39 ng/ml (Q1-Q3: 1.78–2.65 ng/ml), group II Me = 1.85 ng/ml (Q1-Q3: 0.49–0.91 ng/ml), p = 0.034. Strong direct correlations were found (Spearman correlation coefficient S = 0.681 (p < 0.05)) between the zonulin level in feces at the onset of the disease and the development of allergic rhinitis and/or bronchial asthma up to 5 years of age, the data were confirmed by comparing the areas under the curves during ROC analysis, AUC in the study of fecal zonulin as a prognostic marker of the risk of atopic march in children is 0.887, the optimal threshold (cutoff point) is 1.94 ng/ml. Conclusions. Fecal zonulin level in children with food allergy can be an effective prognostic marker of atopic march development, its values in feces above 1.94 ng/ml allow us to predict with a high degree of probability the risk of atopic march development in children with food allergy to cow’s milk proteins within 5 years