Primary association of a MICA allele with protection against rheumatoid arthritis

Arthritis Rheum. 2001 Jun;44(6):1261-5. doi: 10.1002/1529-0131(200106)44:6<1261::AID-ART217>3.0.CO;2-L.


Objective: To determine whether major histocompatibility complex class I chain-related gene A (MICA) polymorphisms are associated with susceptibility to rheumatoid arthritis (RA) independently of the HLA-DRB1 shared epitope (SE).

Methods: Fifty-four Spanish families with an affected son or daughter and 211 consecutive RA patients were genotyped for HLA-DRB1, tumor necrosis factor a/b microsatellite alleles, and MICA transmembrane polymorphism. We performed a case-control comparison with the consecutive patients and an independent transmission disequilibrium test with the families.

Results: The frequency of the MICA 6.0 allele was significantly reduced, compared with controls, in the group of SE+ patients (odds ratio 0.39, P = 0.0005). Additionally, the haplotypes containing this allele were preferentially not transmitted to the affected offspring (9 transmitted of 33; P = 0.007), independent of the presence or absence of an SE either in the same haplotype or in the other haplotype in the progenitor.

Conclusion: These data suggest that the MICA 6.0 allele is an independent marker of protection against RA in the SE+ group of RA patients.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Alleles*
  • Arthritis, Rheumatoid / prevention & control*
  • DNA / analysis
  • Female
  • Gene Frequency
  • Genetic Markers
  • Genetic Predisposition to Disease*
  • Haplotypes / genetics*
  • Histocompatibility Antigens Class I / genetics*
  • Humans
  • Male
  • Middle Aged
  • Polymerase Chain Reaction
  • Polymorphism, Genetic


  • Genetic Markers
  • Histocompatibility Antigens Class I
  • MHC class I-related chain A
  • DNA