title: Associations between interleukin-1 gene polymorphisms and sepsis risk: a meta-analysis.
abstract: BACKGROUND
  Previous epidemiological studies have presented conflicting evidence regarding associations between interleukin-1 (IL-1) polymorphisms and sepsis susceptibility. We have performed a meta-analysis to evaluate possible associations between IL-1 polymorphisms and sepsis risk.
  
  
  METHODS
  Eligible literature was retrieved from PubMed, Embase and Web of Knowledge databases until Jun 15, 2013. The pooled odds ratio (OR) and 95% confidence interval (CI) were calculated using random-effects model in the overall and subgroup analysis based on ethnicity, sepsis severity and quality score.
  
  
  RESULTS
  Eighteen studies addressing five IL-1 polymorphisms were included in this meta-analysis. For IL-1A-889 (rs1800587) polymorphism, significant association was observed in overall comparison for allelic effect (OR = 1.47, 95% CI = 1.01-2.13, P = 0.04). There were no significant associations between either IL-1B-511 (rs16944) or IL-1B-31 (rs1143627) and sepsis susceptibility in overall or subgroup analyses. For IL-1B + 3594 (rs143634) polymorphism, genotype TT decreased sepsis risk in overall analysis (OR = 0.59, 95% CI = 0.36-0.97, P = 0.04), as well as in Caucasian (OR = 0.57, 95% CI = 0.34-0.95, P = 0.03) and sepsis (OR = 0.55, 95% CI = 0.31-0.97, P = 0.04) subgroup analysis. For IL-1RN VNTR polymorphism, significant association was observed in overall comparison for allelic effect (OR = 1.40, 95% CI = 1.01-1.95, P = 0.04). Furthermore, the effect sizes of IL-1RN VNTR on sepsis risk increased with disease severity (septic shock OR > severe sepsis OR > sepsis OR).
  
  
  CONCLUSIONS
  Our meta-analysis indicated that IL-1A-889, IL-1B + 3954 and IL-1RN VNTR might be associated with sepsis susceptibility. However, further studies with larger sample sizes and from homogenous populations would be necessary to validate these findings.
authors.forename: An-Qiang
authors.initials: AQ
authors.lastname: Zhang
authors.forename: Wei
authors.initials: W
authors.lastname: Pan
authors.forename: Jun-Wei
authors.initials: JW
authors.lastname: Gao
authors.forename: Cai-Li
authors.initials: CL
authors.lastname: Yue
authors.forename: Ling
authors.initials: L
authors.lastname: Zeng
authors.forename: Wei
authors.initials: W
authors.lastname: Gu
authors.affiliation: State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Surgery Research, Daping Hospital, Third Military Medical University, Chongqing 400042, China. hellojjx@126.com.
authors.forename: Jian-Xin
authors.initials: JX
authors.lastname: Jiang
mesh_terms: D018740:Genetic Heterogeneity; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D006801:Humans; D007375:Interleukin-1 / Q000235:genetics*; D011110:Polymorphism, Genetic; D018805:Sepsis / Q000235:genetics*
chemical_list: D007375:Interleukin-1