Neutrophilic Steroid-Refractory Recurrent Wheeze and Eosinophilic Steroid-Refractory Asthma in Children.

BACKGROUND: Little is known about inflammatory pathways of severe recurrent wheeze in preschool children and severe asthma in children.

OBJECTIVES: The aim of the Severe Asthma Molecular Phenotype cohort was to characterize phenotypes of severe recurrent wheeze and severe asthma during childhood in terms of triggers (allergic or not), involved cells (eosinophil or neutrophil), and corticoid responsiveness.

METHODS: Children with moderate-to-severe asthma and preschool children with moderate-to-severe recurrent wheeze were enrolled prospectively. They underwent standardized clinical and blood workup, and bronchoalveolar lavage (BAL) evaluation. Cluster analysis was applied to 350 children with 34 variables.

RESULTS: Three clusters were identified: cluster 1, Neutrophilic steroid-refractory recurrent wheeze phenotype, with 138 children uncontrolled despite high-dose inhaled corticosteroids (ICS) (92%, P < .001), with more history of pneumonia (31%, P < .001), more gastroesophageal reflux disease (37%, P < .001), and the highest blood neutrophil count (mean 4.524 cells/mm3 , P = .05); cluster 2, Severe recurrent wheeze with sensitization to a single aeroallergen (12%, P = .002), with 104 children controlled with high-dose ICS (63%, P < .001); cluster 3, Eosinophilic steroid-refractory asthma phenotype, with 108 children uncontrolled despite high-dose ICS (76%, P < .001) with more allergic rhinitis, atopic dermatitis, and food allergies (82%, 40%, 31%, P < .001, respectively). They also had a higher blood eosinophil count and a higher percentage of BAL eosinophil (506/mm3 , 2.6%, P < .001 respectively).

CONCLUSIONS: Inflammation pathway of asthma and recurrent wheeze are related to eosinophil cells in older children and neutrophil cells in younger children. These results could improve personalized treatments.