ABSTRACT
INTRODUCTION: Exacerbations in preschool wheezers increase the
risk of impaired lung function and asthma persistence at school age.
Bronchial remodelling-based latent classes identify severe preschool
wheezers at increased risk of frequent exacerbations
(> 3) but failed to distinguish those without
exacerbation from those with low exacerbations rate (1-2 exacerbations)
in the year following bronchoscopy. We thus aimed to identify further
independent factors associated with no, low or high exacerbation rates.
METHODS: In this post-hoc analysis, 80 severe preschool
wheezers from the “P’tit Asthme” and “RESPIRE” studies were divided
into 3 groups: No-Ex (0 exacerbation in the year following the
bronchoscopy, n=20), Low-Ex (1-2 exacerbations, n=27) and High-Ex (≥3
exacerbations, n=33). Associations between variables and groups were
assessed using multinomial logistic regressions.
RESULTS: Atopic dermatitis, age at the first wheezing episode,Haemophilus and Streptococcus genera in the
bronchoalveolar lavage fluid (BALF), bronchial smooth muscle (BSM) area,
reticular basement membrane (RBM) thickness and RBM-BSM distance were
all significantly different between No-Ex and/or Low-Ex and/or High-Ex.
However, only atopic dermatitis, age at first episode of wheezing,Haemophilus genus in the BALF, RBM-BSM distance and BSM area were
significantly and independently associated with exacerbation frequency.
Among them, the BSM area was the sole parameter independently associated
with each group.
CONCLUSION: While atopic dermatitis, age at the first episode
of wheezing, Haemophilus in BALF, RBM-BSM distance and BSM area
appeared to be relevant independent parameters associated with
exacerbation susceptibility in severe preschool wheezers, only the
increased BSM area discriminated between each of the three-exacerbation
frequency-based groups.