title: Meta-analyses of the association of HLA-DRB1 alleles with rheumatoid arthritis among Arabs.
abstract: OBJECTIVE
  Various studies incorporating Arab populations have reported on specific associations between HLA-DRB1 variants and rheumatoid arthritis (RA). We sought to provide an overview on the association of HLA-DRB1 with RA in Arabs using meta-analysis tools.
  
  
  METHODS
  Data on allele counts and frequencies were compiled from the relevant literature (published before 16 February 2016) and the associations of 13 -DRB1 variants with RA were assessed; relationships were defined in terms of odds ratios (ORs) with a 95% confidence interval.
  
  
  RESULTS
  Based on a collection of six studies, risk conferring or protective allele associations were derived from allele counts in 475 RA patients and 1213 controls. Two HLA-DRB1 alleles (-DRB1*04, *10) significantly conferred an increased risk for RA (OR > 2; P < 0.0001). Conversely, four alleles (-DRB1*03, *07, *11 and *13) significantly conferred a protective effect against RA (OR < 1; P < 0.05). No significant associations with RA were found for seven -DRB1 variants (-DRB1*01, *08, *09, *12, *14, *15 and *16).
  
  
  CONCLUSIONS
  With increased statistical power and effect size over individual studies, we present a more robust profile on the association of HLA-DRB1 variants with RA in the Arab ethnicity, and contribute to the global geo-ethnic picture in this context.
authors.affiliation: Centre for Arab Genomic Studies, Dubai, United Arab Emirates.
authors.forename: Sami
authors.initials: S
authors.lastname: Bizzari
authors.affiliation: Centre for Arab Genomic Studies, Dubai, United Arab Emirates.
authors.forename: Pratibha
authors.initials: P
authors.lastname: Nair
authors.affiliation: Centre for Arab Genomic Studies, Dubai, United Arab Emirates.
authors.forename: Mahmoud Taleb
authors.initials: MT
authors.lastname: Al Ali
authors.affiliation: Centre for Arab Genomic Studies, Dubai, United Arab Emirates.
authors.forename: Abdul Rezzak
authors.initials: AR
authors.lastname: Hamzeh
mesh_terms: D018912:Arabs / Q000235:genetics*; D001172:Arthritis, Rheumatoid / Q000175:diagnosis / Q000208:ethnology / Q000235:genetics*; D016022:Case-Control Studies; D005787:Gene Frequency; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease; D014644:Genetic Variation; D059811:HLA-DRB1 Chains / Q000235:genetics*; D006801:Humans; D016017:Odds Ratio; D010641:Phenotype; D065840:Protective Factors; D018570:Risk Assessment; D012307:Risk Factors
chemical_list: D059811:HLA-DRB1 Chains
keywords: Arabs; HLA-DRB1; genetic susceptibility; rheumatoid arthritis