title: HLA-DRB1 genes and patients with late onset rheumatoid arthritis.
abstract: OBJECTIVE
  To determine the influence of HLA-DRB*1 genes on susceptibility to and severity of rheumatoid arthritis (RA) in patients with late onset compared with younger onset disease.
  
  
  METHODS
  The clinical, biological, and HLA-DRB1 typing characteristics of two groups of patients were studied retrospectively. Group 1 consisted of 262 patients whose disease onset was before or at the age of 60 (young onset RA (YORA)). Group 2 included 60 patients whose illness began after the age of 60 (elderly onset RA (EORA)).
  
  
  RESULTS
  The shared epitope level was similarly increased in both groups of patients compared with normal controls (195/262 (74%) in group 1 and 43/60 (72%) in group 2 v 645/1609 (40.1%) in controls). No differences were noted between the two groups of patients for each separate disease related allele. In contrast, when studying all HLA-DRB1*04 RA related alleles as a group, these alleles were underrepresented in EORA compared with YORA (22/60 (37%) v 135/262 (52%); odds ratio 2.0; 95% confidence interval 1.0 to 3.3). An inverse trend was seen for HLA-DRB1*01 alleles. There were no differences in biological characteristics or extra-articular manifestations between the patient groups. The differences noted in radiological evaluation or the number of prescribed disease modifying antirheumatic drugs seemed to be linked with differences in disease duration.
  
  
  CONCLUSIONS
  HLA-DRB1 RA related alleles influence both EORA and YORA. However, HLA-DRB1*04 RA linked alleles are not as closely associated with RA in the elderly as they are in younger patients. This suggests that the importance of these genes in the susceptibility to RA may be lower in elderly patients.
authors: Fédération de Rhumatologie and INSERM U475, CHU Montpellier, France.
authors: J P
authors: JP
authors: Hellier
authors: J F
authors: JF
authors: Eliaou
authors: J P
authors: JP
authors: Daurès
authors: J
authors: J
authors: Sany
authors: B
authors: B
authors: Combe
mesh_terms: D017668:Age of Onset; D000368:Aged; D000704:Analysis of Variance; D001172:Arthritis, Rheumatoid / Q000235:genetics* / Q000276:immunology*; D016009:Chi-Square Distribution; D000939:Epitopes; D005260:Female; D005802:Genes, MHC Class II; D020022:Genetic Predisposition to Disease; D006684:HLA-DR Antigens / Q000235:genetics*; D059811:HLA-DRB1 Chains; D006801:Humans; D008297:Male; D008875:Middle Aged
chemical_list: D000939:Epitopes; D006684:HLA-DR Antigens; D059811:HLA-DRB1 Chains