Bronchiolitis needs a revisit: Distinguishing between virus entities and their treatments

Jartti, Tuomas; Smits, Hermelijn H.; Bønnelykke, Klaus; Bircan, Ozlem; Elenius, Varpu; Konradsen, Jon R.; Maggina, Paraskevi; Makrinioti, Heidi; Stokholm, Jakob; Hedlin, Gunilla; Papadopoulos, Nikolaos; Ruszczynski, Marek; Ryczaj, Klaudia; Schaub, Bianca; Schwarze, Jürgen; Skevaki, Chrysanthi; Stenberg-Hammar, Katarina; Feleszko, Wojciech

Several observational studies have reported an association between RSV-bronchiolitis and subsequent asthma development. For example, according to a population-based study (n = 476) from Tucson, Arizona, and a birth cohort study (n = 150) from Australia, RSVinduced lower respiratory infection/bronchiolitis during early life is modestly associated with recurrent wheezing/doctor-diagnosed asthma at school-age (odds ratio 2.5-4.3) but not with atopy. 78, 79 Similar numbers have also been found in preterm infants. 80 Only a small cohort study from Sweden has shown an association between RSV-bronchiolitis and later allergic sensitization as well as asthma; by the age 18, 41% of the RSV children were allergic and 39% had asthma compared to the 17% and 9% in the control group, respectively. 81 To address the potential causality between RSV infection and subsequent asthma, prospective studies with RSV-immunoprophylaxis have been performed. Two recent randomized controlled trials showed that in preterm infants, palivizumab, an anti-RSV monoclonal antibody, decreased the parent-reported recurrent wheeze, but similar incidence of physician-diagnosed asthma at age 6 years was found. 82, 83 Long-term effects of RSV prophylaxis appear less likely in infants with atopic family history. 60 These results clearly indicate that RSV-infection is not causal to the asthma or atopy development.