title: Evidence for a causal relationship between allergic sensitization and rhinovirus wheezing in early life.
abstract: BACKGROUND
  Aeroallergen sensitization and virus-induced wheezing are risk factors for asthma development during early childhood, but the temporal developmental sequence between them is incompletely understood.
  
  
  OBJECTIVE
  To define the developmental relationship between aeroallergen sensitization and virus-induced wheezing.
  
  
  METHODS
  A total of 285 children at high risk for allergic disease and asthma were followed prospectively from birth. The timing and etiology of viral respiratory wheezing illnesses were determined, and aeroallergen sensitization was assessed annually for the first 6 years of life. The relationships between these events were assessed using a longitudinal multistate Markov model.
  
  
  RESULTS
  Children who were sensitized to aeroallergens had greater risk of developing viral wheeze than nonsensitized children (hazard ratio [HR], 1.9; 95% confidence interval [CI], 1.2-3.1). Allergic sensitization led to an increased risk of wheezing illnesses caused by human rhinovirus (HRV) but not respiratory syncytial virus. The absolute risk of sensitized children developing viral wheeze was greatest at 1 year of age; however, the relative risk was consistently increased at every age assessed. In contrast, viral wheeze did not lead to increased risk of subsequent allergic sensitization (HR, 0.76; 95% CI, 0.50-1.1).
  
  
  CONCLUSIONS
  Prospective, repeated characterization of a birth cohort demonstrated that allergic sensitization precedes HRV wheezing and that the converse is not true. This sequential relationship and the plausible mechanisms by which allergic sensitization can lead to more severe HRV-induced lower respiratory illnesses support a causal role for allergic sensitization in this developmental pathway. Therefore, therapeutics aimed at preventing allergic sensitization may modify virus-induced wheezing and the development of asthma.
authors.affiliation: University of Wisconsin, Madison, 53792, USA. djj@medicine.wisc.edu
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Jackson
authors.forename: Michael D
authors.initials: MD
authors.lastname: Evans
authors.forename: Ronald E
authors.initials: RE
authors.lastname: Gangnon
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Tisler
authors.forename: Tressa E
authors.initials: TE
authors.lastname: Pappas
authors.forename: Wai-Ming
authors.initials: WM
authors.lastname: Lee
authors.forename: James E
authors.initials: JE
authors.lastname: Gern
authors.forename: Robert F
authors.initials: RF
authors.lastname: Lemanske
mesh_terms: D000485:Allergens / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000150:complications* / Q000276:immunology; D007223:Infant; D007231:Infant, Newborn; D008137:Longitudinal Studies; D008390:Markov Chains; D018448:Models, Immunological; D010850:Picornaviridae Infections / Q000150:complications / Q000276:immunology*; D011446:Prospective Studies; D012135:Respiratory Sounds / Q000276:immunology*; D012229:Rhinovirus
chemical_list: D000485:Allergens