title: Association of MBL2 polymorphism with asthma after bronchiolitis in infancy.
abstract: BACKGROUND
  Mannose-binding lectin (MBL) is a component of innate immunity and has been linked with the pathogenesis of asthma. The aim of the present study was to evaluate the association of MBL genotypes with preschool asthma and allergy in children with bronchiolitis in early infancy.
  
  
  METHODS
  In all, 205 infants were hospitalized for bronchiolitis at <6 months of age. Asthma and allergy were studied from a total of 166 children at 6.4 years (mean). A total of 141 (85%) frozen whole blood samples were available for MBL genotyping and MBL2 gene mutations were determined on pyrosequencing for detection of three single-nucleotide polymorphisms.
  
  
  RESULTS
  Ninety-five children (67.4%) had the wild-type MBL genotype A/A and 46 had A/O or O/O genotypes. Asthma was present in 16 children (11.3%) at 5-7 years of age. Nine children (19.6%) with non-AA genotype had asthma (vs 7.4% of those with genotype AA, P= 0.03). The result remained significant after adjustment for age, gender and atopy. There were no significant associations between MBL genotypes and asthma at any age before the study. Atopic dermatitis, allergic rhinitis or paternal and/or maternal asthma had no significant associations with MBL genotypes.
  
  
  CONCLUSIONS
  The variant non-A/A MBL genotype is associated with asthma after bronchiolitis in infancy, but not earlier than at 5-7 years of age.
authors.affiliation: Paediatric Research Centre, Tampere University and University Hospital, Tampere, Finland. petri.koponen@uta.fi
authors.forename: Petri
authors.initials: P
authors.lastname: Koponen
authors.forename: Qiushui
authors.initials: Q
authors.lastname: He
authors.forename: Merja
authors.initials: M
authors.lastname: Helminen
authors.forename: Kirsi
authors.initials: K
authors.lastname: Nuolivirta
authors.forename: Matti
authors.initials: M
authors.lastname: Korppi
mesh_terms: D001249:Asthma / Q000209:etiology* / Q000235:genetics*; D001988:Bronchiolitis / Q000150:complications*; D002648:Child; D002675:Child, Preschool; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D007223:Infant; D008297:Male; D037601:Mannose-Binding Lectin / Q000097:blood / Q000235:genetics*; D011110:Polymorphism, Genetic; D011446:Prospective Studies; D012307:Risk Factors
chemical_list: C445619:MBL2 protein, human; D037601:Mannose-Binding Lectin