Novel Sensitization Trajectories in Childhood revealed by a Cluster Analysis

Publication date: Available online 25 March 2017
Source:Journal of Allergy and Clinical Immunology
Author(s): Ann-Marie M. Schoos, Bo L. Chawes, Erik Melén, Anna Bergström, Inger Kull, Magnus Wickman, Klaus Bønnelykke, Hans Bisgaard, Morten A. Rasmussen
BackgroundAssessment of sensitization at an isolated time-point during childhood provides limited clinical information. We hypothesized that sensitization develops as specific patterns with respect to age at debut, development over time, and involved allergens, and that such patterns might be more biologically and clinically relevant.ObjectiveTo explore latent patterns of sensitization during the first 6 years of life and investigate whether such patterns associate to development of asthma, rhinitis, and eczema.MethodsWe investigated 398 children from the at-risk Copenhagen Prospective Studies on Asthma in Childhood 2000 birth cohort (COPSAC2000) with specific-IgE against 13 common food and inhalant allergens at ages ½, 1½, 4, and 6yrs. An unsupervised cluster analysis for three-dimensional data (NNS-PARAFAC) was used to extract latent patterns explicitly characterizing temporal development of sensitization, while clustering allergens and children. Subsequently, these patterns were investigated in relation to asthma, rhinitis, and eczema. Verification was sought in an independent unselected birth cohort, BAMSE, constituting 3051 children with specific-IgE against the same allergens at 4 and 8yrs.ResultsThe NNS-PARAFAC analysis indicated a complex latent structure involving seven age- and allergen-specific patterns in the COPSAC2000 data: (1) dog/cat/horse; (2) timothy grass/birch; (3) molds; (4) house dust mites; (5) peanut/wheat flour/mugwort; (6) peanut/soybean; and (7) egg/milk/wheat flour. Asthma was solely associated with pattern 1 (OR=3.3 [1.5-7.2]), rhinitis with patterns 1-4 and 6 (ORs=2.2–4.3) and eczema with patterns 1-3 and 5-7 (ORs=1.6–2.5). All seven patterns were verified in the independent BAMSE cohort (R²>0.89).ConclusionThis study suggests the presence of specific sensitization patterns in early childhood differentially associated to development of clinical outcomes. Using such patterns in future research might provide more robust and clinically relevant results.

Teaser

Sensitization in young children is a make-up of seven distinct patterns defined by the allergens and temporal profile and with different association to allergic disease.


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