Infant Bronchiolitis, Metatranscriptome Profiles, and Pediatric Asthma Risk

pediatric antibiotic use in the first 3 years of life associated with asthma.
pediatric antibiotic use in the first 3 years of life associated with asthma.
A study of infant bronchiolitis identified metatranscriptome profiles and their relationship with host transcriptome and future asthma development.

Metatranscriptome profiles suggest a complex interplay between respiratory virus, airway microbiome, and host immune response in infants with severe bronchiolitis that affects the risk of childhood asthma, according to a study published in the European Respiratory Journal.

Growing evidence supports heterogeneity in the clinical manifestations and pathobiology of bronchiolitis. While studies suggest a complex interplay between viruses, microbiome, and host response and the interrelationship with respiratory health, no studies have integrated virus and airway microbiome data to investigate the metatranscriptome profiles of bronchiolitis in infants.

In the current study, researchers sought to identify the metatranscriptome profiles of infant bronchiolitis and examine their relationship with host transcriptome and subsequent asthma development by conducting a multicenter prospective cohort study of 244 infants (age <12 months) hospitalized for bronchiolitis. The researchers integrated virus and nasopharyngeal metatranscriptome data measured at hospitalization and applied network-based clustering approaches to identify metatranscriptome profiles and their association with host transcriptome and the risk for developing asthma.

Through extensive analysis, the researchers identified 5 biologically-distinct metatranscriptome profiles with differential risks of asthma. The profiles were labelled as: A) virusRSVmicrobiomecommensals; B) virusRSV/RV-AmicrobiomeH.influenzae; C) virusRSVmicrobiomeS.pneumoniae; D) virusRSVmicrobiomeM.nonliquefaciens; and E) virusRSV/RV-CmicrobiomeM.catarrhalis. In particular, infants with the B profile (virusRSV/RV-AmicrobiomeH.influenzae) not only had distinct microbiome function, but were associated with a unique host response in the nasopharyngeal airway at the time of bronchiolitis. Infants with the B profile were characterized by a high proportion of lifetime antibiotics use, history of eczema, parental eczema, IgE sensitization, and coinfection with RV-A, and a higher abundance of H. influenzae than infants with classic bronchiolitis (which corresponded with profile A). In addition, infants with the C profile (virusRSVmicrobiomeS.pneumoniae) had a distinctive microbiome function and host response. Infants with the C profile were characterized by a high proportion of parental asthma and solo-RSV infection as well as a higher abundance of S. pneumoniae. Furthermore, researchers found that both the B and C metatranscriptome profiles had a significantly higher risk for developing childhood asthma than the other 3 profiles.

“Our data suggest a complex interplay between the respiratory virus, airway microbiome, and host immune response, and their integrated contributions to the subsequent development of asthma,” concluded the authors. They added, “For clinicians, our findings may provide an evidence base for the early identification of high-risk children during an important period of airway development — early infancy.”

Disclosure: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures. 


Raita Y, Pérez-Losada M, Freishtat RJ, et al. Nasopharyngeal metatranscriptome profiles of infants with bronchiolitis and risk of childhood asthma: a multicentre prospective study. Eur Respir J. Published online December 16, 2021. doi:10.1183/13993003.02293-2021