title: Cytokine gene polymorphisms and Parkinson's disease: a meta-analysis.
abstract: BACKGROUND
  Cytokines, which are involved in immunological responses, play and important role in the development and progression of Parkinson's disease (PD). The functional polymorphisms identified in cytokine genes are thought to influence PD risk. However the findings of studies investigating the association between cytokine gene polymorphisms and PD risk are still controversial. Therefore, we conducted a meta-analysis, in order to investigate the potential associations between cytokine gene polymorphisms and PD.
  
  
  METHODS
  Studies of PD and cytokine polymorphisms were identified by searches of PubMed and PDGene. Pooled analyses were performed to assess the association between cytokine gene polymorphisms and PD.
  
  
  RESULTS
  Our results indicated a positive association of TNFα -1031 CC genotype in overall analysis(CC vs. TT: OR=3.146; 95%CI: 1.631-6.070, p=0.008; CC vs. CT+TT: OR=3.187: 95%CI: 1.657-6.128,p=0.008), and an Asian subgroup, C variant(OR=1.328; 95%CI: 1.053-1.675, p=0.034) also conveyed an increased PD risk as well as CC genotype ( CC vs. TT: OR=3.207; 95%CI: 1.614-6.373, p=0.004; CC vs. CT+TT: OR=3.238; 95%CI: 1.636-6.410, p=0.004). A decreased risk for PD was associated with IL-6-174C allele (OR=0.761; 95%CI: 0.641-0.903, p=0.008) and IL-1RA VNTR 2 allele(OR=0.641; 95%CI: 0.456-0.826 p=0.004). For the polymorphisms of IL-1β C[-511]T, IL-1α C[-889]T , TNFα G[-308]A, and IL-10 G[-1082]A no significant association was found between the gene polymorphisms and PD risk.
  
  
  CONCLUSIONS
  Our meta-analysis suggested that gene polymorphisms of TNFα -1031, IL-6-174 and IL-1RA VNTR may be associated with PD risk. However, more large well-designed studies will be necessary to validate our findings.
authors.affiliation: Department of Neurology, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.
authors.forename: Ketan
authors.initials: K
authors.lastname: Chu
authors.forename: Xiao
authors.initials: X
authors.lastname: Zhou
authors.forename: Ben-yan
authors.initials: BY
authors.lastname: Luo
mesh_terms: D016207:Cytokines / Q000235:genetics*; D020022:Genetic Predisposition to Disease; D006801:Humans; D010300:Parkinson Disease / Q000235:genetics*; D011110:Polymorphism, Genetic / Q000235:genetics*; D039781:PubMed / Q000706:statistics & numerical data
chemical_list: D016207:Cytokines