Ovalbumin-induced IL-4, IL-5 and IFN-gamma production in infants with atopic dermatitis

Although hen's eggs are considered a cause of infantile atopic dermatitis (AD), little is known about cytokine production upon egg stimulation in infants with AD.

This study aimed to characterize the production of IL-4, IL-5 and IFN-gamma upon stimulation with ovalbumin (OVA), a representative allergenic protein of egg, in infants with AD.

Peripheral blood mononuclear cells (PBMCs) from 68 children with AD, including 46 infants (<1 year), were stimulated with OVA and the production of IL-4, IL-5 and IFN-gamma was measured with ELISA kits.

Upon stimulation with OVA, the production of IL-4 and IL-5, but not IFN-gamma, by PBMCs was significantly higher in infants with AD than in non-atopic controls. OVA-induced IL-5 production peaked in younger infants (2-5 months) and then decreased with age increase. In contrast, OVA-induced IL-4 production peaked at the age of 1-2. This coincided with the serum level of egg white-specific IgE (EW-IgE). There was a significant positive correlation between IL-5 production and the severity of symptoms in infants with AD, while IL-4 production significantly correlated with the serum level of EW-IgE.

These results demonstrate that OVA-induced IL-5 production fluctuates with age in a different manner than IL-4 or EW-IgE. Our results suggest that egg contributes to the development of AD in younger infants by inducing the production of IL-5, but not IL-4.