title: A meta-analysis of the association between the CC chemokine ligand 5 (CCL5) -403 G>A gene polymorphism and tuberculosis susceptibility.
abstract: OBJECTIVE
  Many case-control studies have been performed in the recent past to investigate the association between CCL5 -403 G>A (rs2107538) gene polymorphism and tuberculosis (TB) susceptibility in various ethnic groups. However, these studies have produced inconsistent and contradictory results. In the present study, meta-analysis was performed to assess the association between CCL5 -403 G>A polymorphism and TB risk.
  
  
  METHODS
  Quantitative synthesis was done for the published studies based upon association between CCL5 -403 G>A polymorphism and TB risk from PubMed (Medline), EMBASE web search. Pooled odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated for allele contrast, homozygous, heterozygous, dominant and recessive genetic models.
  
  
  RESULTS
  A total of six studies comprising 1638 confirmed TB cases and 1519 healthy controls were included in this meta-analysis. Variant A allele (A vs. G: p = 0.035; OR = 1.301, 95% CI = 1.019 to 1.662) and variant homozygous (AA vs. GG; p = 0.001; OR = 1.520, 95% CI = 1.202 to 1.923) carriers were significantly associated with TB susceptibility. Similarly, recessive model (AA vs. GG+GA: p = 0.016; OR = 1.791, 95% CI = 1.117 to 2.873) also indicated increased TB risk. Whereas, heterozygous (GA vs. GG: p = 0.837; OR = 1.028, 95% CI = 0.791 to 1.335) and dominant (AA+GA vs. GG: p = 0.222; OR = 1.188, 95% CI = 0.901 to 1.567) models failed to show increased risk of developing TB.
  
  
  CONCLUSIONS
  This meta-analysis suggests that there is a significant association between the CCL5 -403 G>A polymorphism and increased risk of TB. However, larger well-designed epidemiological studies with stratified case control and biological characterization may be helpful to validate this association.
authors.affiliation: Department of Medical Microbiology, College of Nursing and Allied Health Sciences, Jazan University, Jazan, Saudi Arabia.
authors.forename: M Y
authors.initials: MY
authors.lastname: Areeshi
authors.forename: Raju K
authors.initials: RK
authors.lastname: Mandal
authors.forename: Aditya K
authors.initials: AK
authors.lastname: Panda
authors.forename: Shafiul
authors.initials: S
authors.lastname: Haque
mesh_terms: D016022:Case-Control Studies; D018946:Chemokine CCL5 / Q000235:genetics*; D005787:Gene Frequency; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease; D006239:Haplotypes; D006801:Humans; D008957:Models, Genetic; D020641:Polymorphism, Single Nucleotide; D012307:Risk Factors; D014397:Tuberculosis, Pulmonary / Q000235:genetics*
chemical_list: C483024:CCL5 protein, human; D018946:Chemokine CCL5