Inflammatory markers in exhaled breath condensate in nonasthmatic children with food allergy.

ABSTRACT
Introduction: Allergy is a systemic inflammation; therefore, although the allergic symptom may be seen in a specific organ system, the effects of this inflammation may be seen in other organs. IL4, IL5 and IL13 are the major Th2 cytokines and e-cadherin is an epithelial barrier protein. The objective of this research was to assess indicators of inflammation specific to Th2 responses and proteins related to the protective barrier of the airway's inner lining. These assessments were conducted using exhaled breath condensate, which provides insights into the local airway conditions of children suffering from food allergies.
Materials and Methods: The study had 24 patients with food allergy and 24 control individuals younger than three years of age with no history of food reaction. The diagnosis of food allergy was based on food allergen-specific IgE and skin prick test positivity in our clinic and oral food testing in selected cases. Exhaled breath condensate (EBC) samples were obtained by Ecoscreen (Jaegar, Hoechberg, Germany). IL4-5-13 and E-cadherin levels were measured in these samples by ELISA. 
Results: The group of children with food allergies, consisting mainly of 14 girls, had a median age of 16 months, whereas the control group, which included 11 girls, had a median age of 15 months (p=0.89). Comparing the two groups, children with food allergies exhibited notably lower levels of IL-13 in the exhaled breath condensate (EBC) compared to the control group (median values of 59.14 and 76.36, respectively, p=0.02). Conversely, the concentration of IL-4 in the EBC was significantly higher in children with food allergies (median values of 1.94 and 1.29, respectively, p=0.003). However, the levels of IL-5 and e-cadherin showed no significant differences between the two groups (with p-values of 0.74 and 0.09, respectively) as shown in Table 1.
Conclusion: High level of IL-4 despite the low level of IL-13 in the EBC of children having food allergy may be indicative of an early inflammatory phase that is not yet in the effector phase. Studies about the evolution of this process later in life are needed to assess the role of airway inflammation in children with food allergy who develop asthma.
Keywords: IL-4, IL-5, IL-13, E-cadherin&#xD.