title: Gene Polymorphism of Toll-Like Receptors and Lung Function at Five to Seven Years of Age after Infant Bronchiolitis.
abstract: OBJECTIVE
  Toll-like receptors (TLR) play a crucial role in innate immunity, protecting the host from pathogens such as viruses. Genetic variations in TLRs have been associated with the severity of viral bronchiolitis in infancy and with the later occurrence of post-bronchiolitis asthma. The aim of the present study was to evaluate if there are any exploratory associations between TLR gene polymorphisms and lung function at 5 to 7 years of age in former bronchiolitis patients.
  
  
  METHODS
  We performed impulse oscillometry (IOS) at the median age of 6.3 years for 103 children who had been hospitalized for bronchiolitis at less than six months of age. The main parameters evaluated were airway resistance and reactance at 5Hz in baseline and post-exercise measurements. Data on single nucleotide polymorphisms (SNP) of TLR1 rs5743618, TLR2 rs5743708, TLR6 rs5743810 and TLR10 rs4129009 (TLR2 subfamily) and TLR3 rs3775291, TLR4 rs4986790, TLR7 rs179008, TLR8 rs2407992 and TLR 9 rs187084 were available for analyses.
  
  
  RESULTS
  The TLR4 rs4986790 wild genotype A/A was associated with a greater Rrs5 response (0.72 vs. -0.42, p = 0.03) to exercise. In TLR6 rs5743810, the minor allele T was associated with greater Rrs5 response (0.80 vs. -0.03, p = 0.04) to exercise. In TLR7 rs179008, the major allele A was associated with baseline decline in dRrs/df (-1.03 vs 0.61, p = 0.01) and increased Fres (2.28 vs. 0.89, p = 0.01) in girls.
  
  
  CONCLUSIONS
  Among the nine studied TLRs, only TLR7 rs179008 showed some exploratory associations with post-bronchiolitis lung function deficiency, and polymorphisms of TLR4 rs4986790, and TLR6 rs5743810 in particular, with airway reactivity. These findings call for further confirmatory studies.
authors.affiliation: Tampere Center for Child Health Research, Tampere University and University Hospital, Tampere, Finland.
authors.forename: Eero
authors.initials: E
authors.lastname: Lauhkonen
authors.affiliation: Tampere Center for Child Health Research, Tampere University and University Hospital, Tampere, Finland.
authors.forename: Petri
authors.initials: P
authors.lastname: Koponen
authors.affiliation: Department of Medical Microbiology and Immunology, Turku University, Turku, Finland.|Department of Infectious Disease Surveillance and Control, National Institute for Health and Welfare, Turku, Finland.
authors.forename: Juho
authors.initials: J
authors.lastname: Vuononvirta
authors.affiliation: Department of Medical Microbiology and Immunology, Turku University, Turku, Finland.|Department of Infectious Disease Surveillance and Control, National Institute for Health and Welfare, Turku, Finland.
authors.forename: Johanna
authors.initials: J
authors.lastname: Teräsjärvi
authors.affiliation: Seinäjoki Central Hospital, Seinäjoki, Finland.
authors.forename: Kirsi
authors.initials: K
authors.lastname: Nuolivirta
authors.affiliation: Department of Clinical Physiology, Tampere University Hospital, Tampere, Finland.|Department of Clinical Physiology, Turku University Hospital, Turku, Finland.
authors.forename: Jyri O
authors.initials: JO
authors.lastname: Toikka
authors.affiliation: Tampere Center for Child Health Research, Tampere University and University Hospital, Tampere, Finland.
authors.forename: Merja
authors.initials: M
authors.lastname: Helminen
authors.affiliation: Department of Medical Microbiology and Immunology, Turku University, Turku, Finland.|Department of Infectious Disease Surveillance and Control, National Institute for Health and Welfare, Turku, Finland.
authors.forename: Qiushui
authors.initials: Q
authors.lastname: He
authors.affiliation: Tampere Center for Child Health Research, Tampere University and University Hospital, Tampere, Finland.
authors.forename: Matti
authors.initials: M
authors.lastname: Korppi
mesh_terms: D000403:Airway Resistance; D001988:Bronchiolitis / Q000235:genetics; D002648:Child; D002675:Child, Preschool; D005260:Female; D005787:Gene Frequency; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease; D006801:Humans; D008168:Lung / Q000503:physiopathology*; D008297:Male; D020641:Polymorphism, Single Nucleotide; D051197:Toll-Like Receptor 4 / Q000235:genetics*; D051216:Toll-Like Receptor 6 / Q000235:genetics*; D051199:Toll-Like Receptor 7 / Q000235:genetics*
chemical_list: C495345:TLR4 protein, human; C495368:TLR6 protein, human; C495348:TLR7 protein, human; D051197:Toll-Like Receptor 4; D051216:Toll-Like Receptor 6; D051199:Toll-Like Receptor 7