Susceptibility to Lower Respiratory Infections in Childhood is Associated with Perturbation of the Cytokine Response to Pathogenic Airway Bacteria

Abstract

Children at risk of future LRI present a perturbed systemic immune response upon exposure to common airway pathogens in early life.

Neonates colonized with pathogenic bacteria in the airways have a low‐grade systemic inflammation

“…We have previously demonstrated and replicated that asymptomatic bacterial colonization in hypopharynx at age 1 month was associated with the risk of recurrent wheeze, childhood asthma, and lower respiratory tract infections. We also reported that polymorph blood mononuclear cells from children later developing asthma showed an exaggerated ex vivo response to the same airway bacteria at 6 months of age, that is, before disease development . Further, we showed that bacterial colonization in hypopharynx was associated with a local upregulation of pro‐inflammatory immune mediators in the upper airways .…”

Rhinovirus and preschool wheeze

“…The contribution of bacterial colonization to the severity of respiratory symptoms is being discussed. Some studies have reported an aberrant immune response to bacteria in infancy in children with later asthma development, 68 and both bacteria and viruses have been independently shown to be associated with wheeze. 69 Bacterial colonization (with one or several of Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis) in the hypopharynx during the first months after birth in a birth cohort with heredity for asthma/atopy was associated with asthma within the first 5 years of life.…”

Respiratory Syncytial Virus Bronchiolitis: Enter the Microbiome

“…In addition, how does the microbiome affect the airway response to RSV infection? Patterns of colonization are associated with distinct patterns of cytokines and chemokines in nasal fluid (12). Importantly, what mediators bridge the gap between observed changes in inflammation and airway obstruction, and are they of bacterial or host origin?…”