Study design
This study was embedded within the Generation R Study, a prospective birth cohort study located in Rotterdam, the Netherlands. The Medical Ethical Committee of the Erasmus MC, University Medical Center Rotterdam approved the study (MEC-2012-165).17 Written informed consent was obtained from parents or legal representatives of all children. We included all children with European genetic ancestry18 with information on filaggrin mutation (homozygous, compound heterozygous, heterozygous or wild type) and information on at least one of the immune cell outcomes. This resulted in a total number of 523 children (Figure 1).
Our subgroup of children with AD, defined as physician-diagnosed eczema from parental questionnaires obtained at the child’s age of 10 years (‘Was your child ever diagnosed by a physician with atopic dermatitis’, ‘yes; no’) consisted of 102 subjects.16