title: Vitamin D receptor (VDR) polymorphisms and severe RSV bronchiolitis: a systematic review and meta-analysis.
abstract: BACKGROUND
  A number of small studies have suggested a relationship between vitamin D status and severe acute lower respiratory tract infection (ALRI), including RSV-bronchiolitis. The objective of this study was to evaluate the relationship between vitamin D receptor (VDR) polymorphism and severe RSV-bronchiolitis through a systemic literature review and meta-analysis.
  
  
  METHODS
  A comprehensive electronic literature search was conducted to identify all studies published before January 2013. Two reviewers independently screened all abstracts, followed by the full text of potential articles to evaluate eligibility. Study methodological quality was evaluated using the Newcastle Ottawa scale and individual component analysis. Meta-analysis evaluated associations at the allele and genotype levels.
  
  
  RESULTS
  Of 803 studies identified from our literature search, three met eligibility criteria. Two VDR polymorphisms were included in more than one study: TaqI (rs731236) and FokI (rs2228570). All three reported a positive relationship between the FokI minor allele and disease with random effects meta-analyses demonstrating a statistically significant relationship (OR 1.52, CI: 1.12, 2.05). Genotype analysis was highly suggestive of a dominant or incomplete dominance model with combined odds ratios for fF (OR 1.73, CI: 0.92-3.36) and ff (OR 2.24, CI: 0.98-5.14) compared to the FF genotype. No association between TaqI and severe RSV-bronchiolitis was evident at the allele or genotype level.
  
  
  CONCLUSIONS
  Available literature supports an association between the FokI polymorphism and severe RSV disease. Determination of VDR receptor polymorphism status could help predict high-risk infants who might benefit from preventive measures.
authors.affiliation: Department of Pediatrics, Faculty of Medicine, University of Ottawa, Children's Hospital of Eastern Ontario, Ottawa, Canada; Research Institute, Children's Hospital of Eastern Ontario, Ottawa, Canada.
authors.forename: J Dayre
authors.initials: JD
authors.lastname: McNally
authors.forename: Margaret
authors.initials: M
authors.lastname: Sampson
authors.forename: Loren A
authors.initials: LA
authors.lastname: Matheson
authors.forename: Brian
authors.initials: B
authors.lastname: Hutton
authors.forename: Julian
authors.initials: J
authors.lastname: Little
mesh_terms: D000483:Alleles; D001990:Bronchiolitis, Viral / Q000235:genetics*; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D020641:Polymorphism, Single Nucleotide; D018167:Receptors, Calcitriol / Q000235:genetics*; D018357:Respiratory Syncytial Virus Infections / Q000235:genetics*; D012720:Severity of Illness Index
chemical_list: D018167:Receptors, Calcitriol; C579457:VDR protein, human
keywords: pediatrics; risk factors; vitamin D