title: Surfactant protein B gene polymorphism is associated with severe influenza.
abstract: BACKGROUND
  Surfactant proteins play a key role in alveolar stability. We examined whether single nucleotide polymorphisms (SNPs) related to the surfactant protein genes are associated with severe influenza.
  
  
  METHODS
  In the first cohort, 12 SNPs related to surfactant protein genes were compared between Chinese patients with severe and mild pandemic 2009 influenza A(H1N1) (A[H1N1]pdm09) infection who were matched for age, sex, and underlying risk conditions. The SNP rs1130866, which was significantly different between the two groups, was further genotyped in a second cohort of patients. Multivariate analysis was performed to control for confounding factors. The genotype frequencies were also compared with those of the general Han Chinese population.
  
  
  RESULTS
  This study consisted of 380 patients with A(H1N1)pdm09 infection. In the first cohort of 84 patients, the C allele of rs1130866, an SNP in the surfactant protein B gene (SFTPB), was significantly associated with severe disease (OR = 3.37, P = .0048), although the P value was .057 after Bonferroni correction. In the second cohort of 296 patients, the C/C genotype was confirmed in the univariate analysis to be associated with severe disease. Multivariate analysis of the second cohort showed that genotype C/C was an independent risk factor for severe A(H1N1)pdm09 infection (second cohort: OR = 2.087, P = .023). Compared to the general Han Chinese population, the C/C genotype was overrepresented in patients with severe A(H1N1)pdm09 infection (OR = 3.232, P = .00000056).
  
  
  CONCLUSIONS
  SFTPB polymorphism is associated with severe influenza. The role of SFTPB in influenza warrants further studies.
authors: State Key Laboratory for Emerging Infectious Diseases; Carol Yu Centre for Infection; Research Centre of Infection and Immunology; Department of Microbiology.
authors: Kelvin K W
authors: KKW
authors: To
authors: Research Centre of Infection and Immunology; Department of Microbiology.
authors: Jie
authors: J
authors: Zhou
authors: Department of Biochemistry.
authors: You-Qiang
authors: YQ
authors: Song
authors: Carol Yu Centre for Infection; Research Centre of Infection and Immunology; Department of Medicine, The University of Hong Kong, Pokfulam.
authors: Ivan F N
authors: IFN
authors: Hung
authors: Department of Microbiology.
authors: Whitney C T
authors: WCT
authors: Ip
authors: Department of Microbiology.
authors: Zhong-Shan
authors: ZS
authors: Cheng
authors: Department of Microbiology.
authors: Andy S F
authors: ASF
authors: Chan
authors: State Key Laboratory for Emerging Infectious Diseases; Research Centre of Infection and Immunology; Department of Microbiology.
authors: Richard Y T
authors: RYT
authors: Kao
authors: Department of Pathology, Pamela Youde Nethersole Eastern Hospital, Hong Kong Special Administrative Region.
authors: Alan K L
authors: AKL
authors: Wu
authors: Department of Pathology, United Christian Hospital, Hong Kong Special Administrative Region.
authors: Sandy
authors: S
authors: Chau
authors: Department of Pathology, Tseung Kwan O Hospital, Hong Kong Special Administrative Region, China.
authors: Wei-Kwang
authors: WK
authors: Luk
authors: Department of Medicine, The University of Hong Kong, Pokfulam.
authors: Mary S M
authors: MSM
authors: Ip
authors: Carol Yu Centre for Infection; State Key Laboratory for Emerging Infectious Diseases; Research Centre of Infection and Immunology; Department of Microbiology.
authors: Kwok-Hung
authors: KH
authors: Chan
authors: Department of Microbiology; Research Centre of Infection and Immunology; Carol Yu Centre for Infection; State Key Laboratory for Emerging Infectious Diseases. Electronic address: kyyuen@hku.hk.
authors: Kwok-Yung
authors: KY
authors: Yuen
mesh_terms: D000328:Adult; D000368:Aged; D000483:Alleles; D044466:Asian People / Q000235:genetics; D016022:Case-Control Studies; D002681:China; D015331:Cohort Studies; D005260:Female; D020022:Genetic Predisposition to Disease / Q000208:ethnology; D005838:Genotype; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype; D007251:Influenza, Human / Q000208:ethnology / Q000235:genetics* / Q000821:virology*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D020641:Polymorphism, Single Nucleotide; D037701:Pulmonary Surfactant-Associated Protein B / Q000235:genetics*; D012307:Risk Factors; D012720:Severity of Illness Index
chemical_list: D037701:Pulmonary Surfactant-Associated Protein B