Abstract
MeDALL (Mechanisms of the Development of ALLergy) is a FP7 project that aims to generate novel knowledge on the mechanisms of initiation of allergy. We aimed to identify phenotypes of allergic diseases in children using hypothesis-free statistical analyses. A total of 14,625 children (50% female) aged 8 years from 5 European birth cohorts (MAS, BAMSE, PIAMA, LISA, and GINI) were included in a common database with 83 variables obtained through harmonization of standardized questionnaires. Children were grouped, using partitioning cluster analysis (k-means), according to the distribution of 21 variables (phenotypic traits), covering asthma, rhinitis, dermatitis, food allergy, specific IgE levels, and child characteristics. Two groups emerged as the best separation maximizing between- and minimizing within- groups distances. The prevalence of most allergic diseases was different between groups (see Table): 5% vs 54% for ever asthma, 6% vs 54% for ever allergic rhinitis, and 26% vs 69% for ever eczema, in Groups 1 and 2, respectively. Specific IgE positivity was observed in 28% and 64% of children, respectively.
Thus, Group 1 could correspond to healthy children from the general population, while Group 2 puts together children with the different allergic diseases. These data suggest that allergic diseases could be better approached as one single entity rather than as independent, solely organ-related diseases.
- © 2012 ERS