title: Differential association of HLA-DRB1 alleles in Japanese patients with early rheumatoid arthritis in relationship to autoantibodies to cyclic citrullinated peptide.
abstract: OBJECTIVE
  To evaluate the role of HLA-DRB1 genotypes and antibodies to cyclic citrullinated peptides (anti-CCP antibodies) in the development and radiographic progression of Japanese patients with rheumatoid arthritis (RA).
  
  
  METHODS
  One hundred and ten patients with early RA (88 female, 22 male) who visited our clinic within 1 year of symptom onset were examined for anti-CCP antibody levels and HLA-DRB1 genotypes. HLA-DRB1 genotypes were also determined in 265 healthy controls. Radiographic progression over a 2-year interval was evaluated using the Larsen's method in 66 patients.
  
  
  RESULTS
  Among the 110 patients with early RA, 82 patients (74.5%) were anti-CCP positive. Carrier frequency of HLA-DRB1*0405 was significantly increased in RA patients with anti-CCP antibodies compared with controls and RA patients without anti-CCP antibodies (odds ratio [OR] 3.4, 95% confidence interval [95% CI] 2.0-5.7 and OR 3.3, 95% CI 1.3-8.6, respectively). Carriership of one or two SE alleles was significantly associated with production of anti-CCP antibodies (OR 2.7, 95% CI 1.1-6.7 and OR 9.3, 95% CI 1.1-78.2, respectively). On the other hand, allele frequency of HLA-DRB1*0901 was significantly increased in RA patients without anti-CCP antibodies compared with controls and RA patients with anti-CCP antibodies (OR 2.2, 95% CI 1.1-4.1 and OR 3.0, 95% CI 1.4-6.4, respectively).
  
  
  CONCLUSIONS
  In Japanese patients with RA, HLA-DRB1 SE alleles are associated with production of anti-CCP antibodies and HLA-DRB1 alleles appear to be differently associated with early RA depending on anti-CCP positivity as in Caucasian patients with RA.
authors.affiliation: Institute of Rheumatology, Tokyo Women's Medical University, Tokyo, Japan. furuyat@ior.twmu.ac.jp
authors.forename: T
authors.initials: T
authors.lastname: Furuya
authors.forename: M
authors.initials: M
authors.lastname: Hakoda
authors.forename: N
authors.initials: N
authors.lastname: Ichikawa
authors.forename: K
authors.initials: K
authors.lastname: Higami
authors.forename: Y
authors.initials: Y
authors.lastname: Nanke
authors.forename: T
authors.initials: T
authors.lastname: Yago
authors.forename: T
authors.initials: T
authors.lastname: Kobashigawa
authors.forename: K
authors.initials: K
authors.lastname: Tokunaga
authors.forename: N
authors.initials: N
authors.lastname: Tsuchiya
authors.forename: N
authors.initials: N
authors.lastname: Kamatani
authors.forename: S
authors.initials: S
authors.lastname: Kotake
mesh_terms: D000328:Adult; D000483:Alleles; D001172:Arthritis, Rheumatoid / Q000208:ethnology / Q000235:genetics* / Q000276:immunology*; D044466:Asian People / Q000208:ethnology / Q000235:genetics; D001323:Autoantibodies / Q000097:blood*; D016022:Case-Control Studies; D018450:Disease Progression; D000939:Epitopes / Q000235:genetics; D005260:Female; D005528:Foot / Q000000981:diagnostic imaging; D005838:Genotype; D006684:HLA-DR Antigens / Q000235:genetics*; D059811:HLA-DRB1 Chains; D006225:Hand / Q000000981:diagnostic imaging; D006579:Heterozygote; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D010456:Peptides, Cyclic / Q000235:genetics / Q000276:immunology*; D011859:Radiography
chemical_list: D001323:Autoantibodies; D000939:Epitopes; D006684:HLA-DR Antigens; D059811:HLA-DRB1 Chains; D010456:Peptides, Cyclic; C487763:cyclic citrullinated peptide