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

The strongest asthma locus discovered to date, 17q21, has also been found to be associated with wheezing during the early years of life. 26 Furthermore, there is an interaction between this locus and early wheezing in relation to the risk of later asthma. Wheezing episodes during the early years of life are a much stronger risk factor for asthma in children with 17q21 risk variants than in children without it, and this seems more pronounced for episodes triggered by RV than RSV. 26 Another asthma gene with a putative role in bronchiolitis is the cadherin-related family member 3 (CDHR3). This gene was first discovered as a susceptibility gene for early childhood asthma with recurrent severe exacerbations. 27 Only later was it suggested from experimental studies that CDHR3 also functions as an RV-C receptor. 28 This was subsequently confirmed clinically in the COPSAC and COAST birth cohort studies where the CDHR3 risk variant was specifically associated with early life respiratory episodes triggered by RV-C. 29 In line with this, a meta-analyses of CDHR3 polymorphism in relation to bronchiolitis an association with non-RSV bronchiolitis, which is likely to be triggered by RV, while there was no association with RSV bronchiolitis. 30