Epigenetic profiling of children with respiratory allergy

The prevalence of respiratory allergy in children is increasing. Epigenetic changes (e.g. DNA methylation) are plausible underlying molecular mechanisms. Longitudinal birth cohorts are instrumental to study the relation between early-life environmental factors and the development of complex diseases. Our AXA Research Fund and Cefic-LRI supported project explores the hypothesis that chemical exposures during pregnancy can influence the immune system and development of allergy in children. Questionnaire data, as well as cord blood, plus blood and saliva samples at age 11 years, were collected in substudies of two longitudinal birth cohorts in Belgium (FLEHS1 & FLEHS2) and analyzed with Illumina Methylation 450K BeadChips as well as gene targeted iPLEX MassArrays analysis. The project aims to answer the following questions: 1) can we identify specific changes in epigenetic modifications on DNA from allergic compared to not-allergic children; 2) are these allergy-related epigenetic changes a result of chemical exposure during pregnancy; and 3) did the early life exposures leave an epigenetic “mark” that is maintained through childhood. If chemicals exposures and resulting predictive markers of allergic diseases can be detected early, prevention strategies, particularly in children or before pregnancy, could be developed. Bisulphite converted DNA from 93 cord blood (PBMC fraction), 92 blood (PBMC fraction), 53 saliva samples were hybridised to the Illumina Infinium 450k Human Methylation Beadchip