RSV hospitalization in infancy increases the risk of current wheeze at age 6 in late preterm born children without atopic predisposition.

Severe respiratory syncytial virus (RSV) infection during infancy is associated with ongoing respiratory morbidity. In a large birth cohort of 2210 healthy preterm infants born at 32-35 weeks of gestation, we aimed to determine the role of atopy in the link between RSV hospitalization and current wheeze at age 6. We defined current wheeze as parent-reported wheeze or the use of respiratory medication in the past 12 months. Based on a positive family history of atopic disease, we distinguished between children with and without atopic predisposition. Six-year follow-up data was obtained in 997/1559 (64%) children of which 102 (10.2%) children had been hospitalized with RSV during infancy. Current wheeze was present in 184/997 (18.6%) children. RSV hospitalization was an independent risk factor for current wheeze in children without atopic predisposition (aOR 4.05 [95% CI 1.22-12.52]) but not in children with this atopic background (aOR 1.50 [95% CI 0.81-2.71]).Conclusion: This is the largest published birth cohort demonstrating that in late preterm infants, atopic predisposition defines the relationship between RSV hospitalization and current wheeze. Future RSV prevention trials aiming to prevent ongoing respiratory symptoms should be analyzed separately for atopic status. What is Known: • RSV infection is responsible for a significant burden of disease in young children worldwide. • Severe RSV infection in early life is associated with asthmatic symptoms later in life. What is New: • This is the largest published birth cohort reporting about the role of atopic predisposition in the link between severe RSV infection and current wheeze at school age. • We show that RSV hospitalization in infancy is an independent risk factor for current wheeze in late preterm children without atopic predisposition at age 6. This was not seen in children with atopic predisposition.