Postnatal Infections and Adaptive Immunology of Bronchopulmonary Dysplasia

Abstract Bronchopulmonary dysplasia (BPD) and chronic lung disease (CLD) of prematurity result from the culmination of multiple exposures. Respiratory viral illnesses (RVIs) and either a dysregulated or an insufficient host response combine to have a significant detrimental effect on the injured lung of the premature infant. RVIs are now understood to contribute to the severity of BPD in exposed infants and account for a majority of outpatient healthcare visits after discharge from neonatal intensive care unit. Premature infants with early RVI are at high risk for postviral wheezing and diminished respiratory function, even without a preceding diagnosis of BPD. The pathogenesis of RVI-induced respiratory morbidity is thought to result from a combination of viral cytopathic effects and immune-mediated collateral damage. This chapter will review the epidemiology and pathogenesis of RVIs in premature infants, with a particular focus on the unique adaptive immune-system-mediated activities at play during early human development.