Cord blood methylation at TNFRSF17 is associated with early allergic phenotypes.

Food allergy and eczema are the earliest allergic phenotypes in childhood. These diseases could be related to either IgE-mediated or non-IgE-mediated reactions to the allergen. TNFRSF17 is a key molecule in B cell maturation and is important in both types of responses.We conducted a study comparing the relative expression and the methylation status at the TNFRSF17 in regard to the child's early atopic sensitisation and allergic phenotypes.In the recruited population of 200 women and 174 children with available clinical data (physical examination by allergist and antigen-specific IgE measurements), 78 cord blood samples were included in the gene expression analysis (relative gene expression with GAPDH as reference by RT-PCR) and 96 samples with microarray DNA methylation data (whole genome methylation profile Infinium MethylationEPIC).The altered TNFRSF17 methylation pattern in the cord blood at both single cg04453550 and mean methylation at upstream of TNFRSF17 was observed in children who developed food allergy and/or eczema in early childhood. The change in methylation profile was mirrored by the relative expression. The profile of IgE sensitisation to food and/or inhalant allergens was not significantly associated with either methylation or expression of TNFRSF17.In conclusion, methylation at the upstream sites at TNFRSF17 in the cord blood at birth is associated with food allergy and eczema early in childhood.