Introduction
Severe asthma (SA) in school-age children (7-12 years) and severe
recurrent wheeze (SRW) in preschool children (3-6 years) affect less
than 5% of children with asthma (1). They are heterogeneous conditions
characterized by multiple phenotypes based on various features such as
an association with other atopic conditions, environmental factors, lung
function impairment, type of underpinning inflammation, or allergenic
sensitization (2–4).
Several studies have highlighted the impact of sensitization in the
natural history of asthma. In particular, early and multiple occurrences
of sensitization have been shown to be associated with severe persistent
asthma and lung function impairment throughout childhood (5–9).
However, it is still unclear whether severity in preschool and
school-age children is underpinned by different patterns of
sensitization (10). Component resolved-diagnostics (CRD) detects IgE
specific to individual allergen molecules (components, c-sIgE) rather
than whole extracts and has been used in previous studies to
characterize sensitization profiles in children (5–7,10). Previous
results from the Pediatric Cohort of Bronchial Obstruction and Asthma
(COBRAPed), a French multicenter prospective observational cohort of
preschool (3-6 years) and school-age children (7-12 years) with
recurrent wheeze/asthma, suggest a role for both environmental factors
and atopy in asthma severity (11). Thus, the description of
sensitization profiles using CRD in this well-described population
provides an opportunity to further study the relationship between
allergic sensitization and asthma severity during childhood. The main
objective of our study was to determine whether sensitization patterns
(biological sources and allergen components) can discriminate between
children with NSRW/NSA and those with SRW/SA.