title: IL-1β+3953C/T, -511T/C and IL-6 -174C/G polymorphisms in association with tuberculosis susceptibility: A meta-analysis.
abstract: BACKGROUND
  Studies of the association between the interleukin-1β gene (IL-1β) (+3953C/T, -511T/C) and interleukin-6 gene (IL-6) (-174G/C) polymorphisms and susceptibility to tuberculosis (TB) have yielded inconsistent results. The aim of this study was to investigate the relationship between these polymorphisms and TB risk by this meta-analysis.
  
  
  METHODS
  We systematically searched published literatures on IL-1β gene and IL-6 gene polymorphisms and tuberculosis risk by the PubMed, Medline, Embase, Web of Science, Elsevier Science Direct and Cochrane Library databases, and identified outcome data from all articles. Statistical analysis was performed using Stata 12.0. A total of 15 studies comprising 3983TB patients and 3996 controls were included in the present study.
  
  
  RESULTS
  We found that the IL-6 -174C/G polymorphism might be associated with decreased risk of TB (C vs. G: OR=0.77, 95% CI=0.64-0.91; CG vs. GG: OR=0.72, 95% CI=0.57-0.90; CC+CG vs. GG: OR=0.71, 95% CI=0.57-0.88). In the stratified analysis by ethnicity, significantly decreased risk were observed for IL-1β -511T/C polymorphism in Africans (C allele vs. T allele: OR=0.86, 95% CI=0.74-0.99; CC vs. TT: OR=0.74, 95% CI=0.55-0.99). Moreover, the IL-6 -174 C/G polymorphism was also associated with decreased risk of TB in Asians (C vs. G: OR=0.71, 95% CI=0.54-0.93; CG vs. GG: OR=0.61, 95% CI=0.44-0.85; CC+CG vs. GG: OR=0.63, 95% CI=0.46-0.86). We also performed the analyses by sample types in IL-6 -174 C/G polymorphism, and significant decreased TB risk was observed in pulmonary tuberculosis group (C allele vs. G allele: OR=0.69, 95% CI=0.52-0.93; CG vs. GG: OR=0.69, 95% CI=0.52-0.91; CC+CG vs. GG: OR=0.71, 95% CI=0.55-0.93), and pulmonary tuberculosis plus extra-pulmonary tuberculosis mixed group (CC vs. GG: OR=0.44, 95% CI=0.22-0.88; CC vs. CG+GG: OR=0.48, 95% CI=0.25-0.94).
  
  
  CONCLUSIONS
  This meta-analysis indicates that the IL-1β -511T/C polymorphism is associated with TB decreased risk in Africans, and IL-6 -174C/G polymorphism in Asians. Further well-designed, large scale studies are required to confirm this conclusion.
authors.affiliation: Department of Clinical Laboratory, Central Hospital of Wuhan, No. 26, Shengli Street, Jiangan District, Wuhan 430014, Hubei Province, PR China.
authors.forename: Xiaolu
authors.initials: X
authors.lastname: Mao
authors.affiliation: Department of Pharmacy, Renmin Hospital, Hubei University of Medicine, 39 Chaoyang Mid-Road, Shiyan 442000, Hubei Province, PR China.
authors.forename: Zunqiong
authors.initials: Z
authors.lastname: Ke
authors.affiliation: Department of Central Laboratory, Central Hospital of Wuhan, No. 26, Shengli Street, Jiangan District, Wuhan 430014, Hubei Province, PR China.
authors.forename: Shuiyi
authors.initials: S
authors.lastname: Liu
authors.affiliation: Department of Clinical Laboratory, Central Hospital of Wuhan, No. 26, Shengli Street, Jiangan District, Wuhan 430014, Hubei Province, PR China.
authors.forename: Beibei
authors.initials: B
authors.lastname: Tang
authors.affiliation: Department of Clinical Laboratory, Central Hospital of Wuhan, No. 26, Shengli Street, Jiangan District, Wuhan 430014, Hubei Province, PR China.
authors.forename: Jin
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Clinical Laboratory, Central Hospital of Wuhan, No. 26, Shengli Street, Jiangan District, Wuhan 430014, Hubei Province, PR China.
authors.forename: Hao
authors.initials: H
authors.lastname: Huang
authors.affiliation: Department of Radiology, Central Hospital of Wuhan, No.26, Shengli Street, Jiangan District, Wuhan 430014, Hubei Province, PR China. Electronic address: Songchen2020@163.com.
authors.forename: Song
authors.initials: S
authors.lastname: Chen
mesh_terms: D020022:Genetic Predisposition to Disease; D006801:Humans; D053583:Interleukin-1beta / Q000235:genetics*; D015850:Interleukin-6 / Q000235:genetics*; D011110:Polymorphism, Genetic; D014376:Tuberculosis / Q000235:genetics*
chemical_list: D053583:Interleukin-1beta; D015850:Interleukin-6
keywords: Interleukin-1β; Interleukin-6; Meta-analysis; Polymorphism; Tuberculosis; susceptibility