title: HLA associations of seropositive rheumatoid arthritis in a Cree and Ojibway population.
abstract: OBJECTIVE
  To determine the HLA associations of seropositive rheumatoid arthritis (RA) in a Cree and Ojibway population; to determine whether specific alleles distinguish juvenile or adult onset.
  
  
  METHODS
  HLA-A, B, C, and DRB1 alleles were analyzed in 23 Ojibway and Cree patients with RA seen in a single tertiary care center. Comparisons were made with published results of controls and with results of 18 patients with rheumatoid factor (RF) positive polyarticular juvenile rheumatoid arthritis (JRA) from the same population.
  
  
  RESULTS
  Comparisons among patients with RA, patients with RF positive polyarticular JRA, and controls showed increased frequencies of the RA shared epitope in patients with RA and of DRB1*0901 in patients with seropositive polyarticular JRA, while the frequency of DRB1*08 alleles was decreased in patients with RF positive polyarticular JRA.
  
  
  CONCLUSIONS
  In this population, DRB1*0901 may promote while DRB1*08 alleles may protect against a juvenile onset of RA specifically. In contrast, the RA shared epitope may have a greater effect on the risk of adult onset seropositive RA. Due to the small patient numbers, these results require confirmation.
authors.affiliation: Department of Pediatrics and Child Health, University of Manitoba and the Health Sciences Centre, Winnipeg, Canada.
authors.forename: K
authors.initials: K
authors.lastname: Oen
authors.forename: H S
authors.initials: HS
authors.lastname: El-Gabalawy
authors.forename: J M
authors.initials: JM
authors.lastname: Canvin
authors.forename: C
authors.initials: C
authors.lastname: Hitchon
authors.forename: I M
authors.initials: IM
authors.lastname: Chalmers
authors.forename: M
authors.initials: M
authors.lastname: Schroeder
authors.forename: K
authors.initials: K
authors.lastname: Jacobson
authors.forename: M
authors.initials: M
authors.lastname: Reed
authors.forename: S
authors.initials: S
authors.lastname: Wood
authors.forename: M
authors.initials: M
authors.lastname: Cheang
mesh_terms: D000328:Adult; D000368:Aged; D000483:Alleles; D001172:Arthritis, Rheumatoid / Q000097:blood / Q000453:epidemiology / Q000235:genetics*; D002170:Canada / Q000453:epidemiology; D016022:Case-Control Studies; D005787:Gene Frequency; D006680:HLA Antigens / Q000235:genetics*; D015234:HLA-A Antigens / Q000235:genetics; D015235:HLA-B Antigens / Q000235:genetics; D006684:HLA-DR Antigens / Q000235:genetics; D059811:HLA-DRB1 Chains; D006650:Histocompatibility Testing; D006801:Humans; D007198:Indians, North American / Q000235:genetics*; D008875:Middle Aged
chemical_list: D006680:HLA Antigens; D015234:HLA-A Antigens; D015235:HLA-B Antigens; D006684:HLA-DR Antigens; D059811:HLA-DRB1 Chains