Shared epitope alleles remain a risk factor for anti-citrullinated proteins antibody (ACPA)--positive rheumatoid arthritis in three Asian ethnic groups

PLoS One. 2011;6(6):e21069. doi: 10.1371/journal.pone.0021069. Epub 2011 Jun 15.

Abstract

Background: To investigate the associations between HLA-DRB1 shared epitope (SE) alleles and rheumatoid arthritis in subsets of rheumatoid arthritis defined by autoantibodies in three Asian populations from Malaysia.

Methods: 1,079 rheumatoid arthritis patients and 1,470 healthy controls were included in the study. Levels of antibodies to citrullinated proteins (ACPA) and rheumatoid factors were assessed and the PCR-SSO method was used for HLA-DRB1 genotyping.

Results: The proportion of ACPA positivity among Malay, Chinese and Indian rheumatoid arthritis patients were 62.9%, 65.2% and 68.6%, respectively. An increased frequency of SE alleles was observed in ACPA-positive rheumatoid arthritis among the three Asian ethnic groups. HLA-DRB1*10 was highly associated with rheumatoid arthritis susceptibility in these Asian populations. HLA-DRB1*0405 was significantly associated with susceptibility to rheumatoid arthritis in Malays and Chinese, but not in Indians. HLA-DRB1*01 did not show any independent effect as a risk factor for rheumatoid arthritis in this study and HLA-DRB1*1202 was protective in Malays and Chinese. There was no association between SE alleles and ACPA- negative rheumatoid arthritis in any of the three Asian ethnic groups.

Conclusion: The HLA-DRB1 SE alleles increase the risk of ACPA-positive rheumatoid arthritis in all three Asian populations from Malaysia.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alleles*
  • Antibodies / chemistry
  • Antibodies / genetics*
  • Asia / ethnology
  • Citrulline / immunology*
  • Epitopes / genetics*
  • Ethnic Groups*
  • Female
  • HLA-DR Antigens / genetics
  • HLA-DRB1 Chains
  • Humans
  • Male
  • Rheumatoid Factor / immunology
  • Risk Factors

Substances

  • Antibodies
  • Epitopes
  • HLA-DR Antigens
  • HLA-DRB1 Chains
  • HLA-DRB1*12:02 antigen
  • Citrulline
  • Rheumatoid Factor