title: Influence of HLA-DRB1 genes and the shared epitope on genetic susceptibility to rheumatoid arthritis in Taiwanese.
abstract: OBJECTIVE
  To investigate the association of predisposing and protective HLA-DRB1 alleles with rheumatoid arthritis (RA) and its clinical markers in a Taiwanese population.
  
  
  METHODS
  A total of 273 patients with RA and 480 healthy controls, all of Taiwanese origin, were genotyped for HLA-DRB1 alleles by polymerase chain reaction and sequence-based typing assays. The associations between RA and HLA-DRB1 alleles and genotypes were investigated by chi-squared test.
  
  
  RESULTS
  The DRB1*0405 and *1001 phenotypes showed the most significant associations with RA (OR 4.04, 95% CI 2.84-5.77, pc = 3.2 10(-14); OR 5.25, 95% CI 2.10-13.06, pc = 3.0 10(-3), respectively). Individuals carrying single or double doses of the shared epitope (SE/non-SE or SE/SE) had higher risks of RA. The compound heterozygote of DRB1*0405/*1001 showed the largest increase in RA risk (OR 15.8, 95% CI 2.48-100.7, pc = 0.004). Single or double doses of SE alleles were significantly associated with a higher bone erosion rate. Rheumatoid factor positivity and bone erosion were more frequent in patients with at least one copy of DRB1*0405.
  
  
  CONCLUSIONS
  Our results show that SE-encoding HLA-DRB1*0405 and *1001 are associated with RA in a Taiwanese population; this is the first time DRB1*1001 has been described in persons of Asian ethnicity. Heterozygotes of DRB1*0405 and *1001 predicted the strongest susceptibility to RA, suggesting that this genotype enhances susceptibility to RA in Taiwanese.
authors.affiliation: Department of Orthopedic Surgery, Mackay Memorial Hospital, Taipei, Taiwan.
authors.forename: Shih-Chia
authors.initials: SC
authors.lastname: Liu
authors.forename: Tzu-Yang
authors.initials: TY
authors.lastname: Chang
authors.forename: Yann-Jinn
authors.initials: YJ
authors.lastname: Lee
authors.forename: Chen-Chung
authors.initials: CC
authors.lastname: Chu
authors.forename: Marie
authors.initials: M
authors.lastname: Lin
authors.forename: Zong-Xian
authors.initials: ZX
authors.lastname: Chen
authors.forename: Hsin-Fu
authors.initials: HF
authors.lastname: Liu
authors.forename: Ching-Wen
authors.initials: CW
authors.lastname: Dang
authors.forename: Shih-Chuan
authors.initials: SC
authors.lastname: Chang
authors.forename: Chyou-Shen
authors.initials: CS
authors.lastname: Lee
authors.forename: Tien-Ling
authors.initials: TL
authors.lastname: Chen
authors.forename: Chun-Hsiung
authors.initials: CH
authors.lastname: Huang
mesh_terms: D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000453:epidemiology / Q000208:ethnology / Q000235:genetics* / Q000276:immunology; D001483:Base Sequence; D016022:Case-Control Studies; D005260:Female; D020022:Genetic Predisposition to Disease / Q000453:epidemiology*; D005838:Genotype; D006684:HLA-DR Antigens / Q000235:genetics* / Q000276:immunology; D059811:HLA-DRB1 Chains; D006801:Humans; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D010641:Phenotype; D013624:Taiwan / Q000453:epidemiology
chemical_list: D006684:HLA-DR Antigens; D059811:HLA-DRB1 Chains