title: Surfactant protein A2 polymorphisms and disease severity in a respiratory syncytial virus-infected population.
abstract: OBJECTIVE
  To examine whether genetic variations within the surfactant protein A2 (SP-A2) gene are associated with respiratory syncytial virus (RSV) disease severity in infected children.
  
  
  METHODS
  Naturally infected children aged < or =24 months were prospectively enrolled in 3 RSV seasons. SP-A2 genotyping was performed. Independent clinical predictors of disease severity were analyzed. The association of SP-A2 genetic diversity and disease severity was tested by using multivariate logistic regression models and 4 levels of disease gradation as outcome measures.
  
  
  RESULTS
  Homozygosity of the 1A(0) allele was protective against hospitalization (odds ratio [OR] = 0.15, P = .0010). This remained significant in African American patients (OR = 0.24, P = .042) and Caucasian patients (OR = 0.05, P = .021) after adjustment for other co-variates. Hospitalized children with the 1A(2) allele demonstrated significant protection from severe disease with univariate analyses, but only a trend for protection with multivariate analyses. Patients homozygous or heterozygous for an asparagine at amino acid position 9 were twice or more likely to need intensive care unit admission (OR = 2.15, P = .022), require intubation (OR = 3.04, P = .005), and have a hospitalization lasting > or =4 days (OR = 1.89, P = .02) compared with children homozygous for a threonine at this position.
  
  
  CONCLUSIONS
  SP-A2 polymorphisms are associated with the severity of RSV infection in infants.
authors.affiliation: Department of Pediatrics, Harvard Medical School, Massachusetts General Hospital for Children, Boston, MA 02114, USA. celsaleeby@partners.org
authors.forename: Chadi M
authors.initials: CM
authors.lastname: El Saleeby
authors.forename: Rongling
authors.initials: R
authors.lastname: Li
authors.forename: Grant W
authors.initials: GW
authors.lastname: Somes
authors.forename: Mary K
authors.initials: MK
authors.lastname: Dahmer
authors.forename: Michael W
authors.initials: MW
authors.lastname: Quasney
authors.forename: John P
authors.initials: JP
authors.lastname: DeVincenzo
mesh_terms: D002675:Child, Preschool; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D006760:Hospitalization; D006801:Humans; D007223:Infant; D015278:Intensive Care Units, Pediatric; D007902:Length of Stay; D008297:Male; D020641:Polymorphism, Single Nucleotide; D037662:Pulmonary Surfactant-Associated Protein A / Q000235:genetics*; D012121:Respiration, Artificial; D018357:Respiratory Syncytial Virus Infections / Q000235:genetics* / Q000628:therapy; D012141:Respiratory Tract Infections / Q000235:genetics* / Q000628:therapy; D020539:Sequence Analysis, Protein; D012720:Severity of Illness Index
chemical_list: D037662:Pulmonary Surfactant-Associated Protein A; C445843:SFTPA2 protein, human