title: Comparative study of elderly-onset rheumatoid arthritis and young-onset rheumatoid arthritis in a Colombian population: clinical, laboratory and HLA-DRB1 findings.
abstract: OBJECTIVE
  Elderly-onset rheumatoid arthritis (EORA) is considered to have different features in relation to young-onset rheumatoid arthritis (YORA). However, results from different evaluated populations worldwide have been inconsistent and in Colombia there are no known descriptions of the differences between these pathologies. The aim of this paper is to compare the clinical, laboratory and immunogenetic features in a Colombian population suffering with EORA and YORA.
  
  
  METHODS
  EORA (≥65, n=104) and YORA (<65, n=96) patients were compared regarding clinical, laboratory and HLA-DRB1 alleles features. A control group without rheumatoid arthritis over 65 (n=179) was used to compare the HLA-DRB1 alleles. All patients met the ACR/1987 criteria for rheumatoid arthritis and the clinimetric index was calculated.
  
  
  RESULTS
  The gender ratio (female/male) was 1.8:1 in EORA. In both groups, the main onset pattern of disease was an insidious polyarticular onset (p=0.35). EORA was characterised by more distal-proximal joint involvement in comparison to YORA (p=0.0007). In EORA, the rheumatoid factor and anti-cyclic citrullinated peptide (anti-CCP) antibodies frequency was close to 50%, lower than in YORA (63%). In both groups, the DAS28 and HAQ-DI score was higher than 6 and 1, respectively. The HLA-DRB1*0403 and *1402 frequency was significantly higher in EORA than in YORA. Also, the shared epitope (p=0.0392), HLA-DRB1*01 (p=0.0068) and *0101 (p=0.0151) were associated with an anti-CCP positivity and the HLA-DRB1*0403 is protective for the anti-CCP presence in EORA (p=0.0201).
  
  
  CONCLUSIONS
  EORA is characterised by a different clinical presentation and HLA-DRB1 alleles with respect to YORA. HLA-DRB1*0403 and *1402 are significantly more frequent in EORA compared to YORA.
authors.affiliation: Universidad Nacional de Colombia, Bogota, Colombia. nspinelb@gmail.com
authors.forename: Néstor
authors.initials: N
authors.lastname: Spinel-Bejarano
authors.forename: Gerardo
authors.initials: G
authors.lastname: Quintana
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Heredia
authors.forename: Juan José
authors.initials: JJ
authors.lastname: Yunis
authors.forename: Jorge E
authors.initials: JE
authors.lastname: Caminos
authors.forename: Maria F
authors.initials: MF
authors.lastname: Garcés
authors.forename: Federico
authors.initials: F
authors.lastname: Rondon
authors.forename: Antonio
authors.initials: A
authors.lastname: Iglesias-Gamarra
mesh_terms: D000328:Adult; D017668:Age of Onset; D000368:Aged; D000704:Analysis of Variance; D001172:Arthritis, Rheumatoid / Q000175:diagnosis / Q000453:epidemiology* / Q000235:genetics* / Q000276:immunology; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D003105:Colombia / Q000453:epidemiology; D003430:Cross-Sectional Studies; D004185:Disability Evaluation; D005260:Female; D005787:Gene Frequency; D059811:HLA-DRB1 Chains / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D010456:Peptides, Cyclic / Q000276:immunology; D015995:Prevalence; D012217:Rheumatoid Factor / Q000097:blood; D012307:Risk Factors; D012720:Severity of Illness Index
chemical_list: D015415:Biomarkers; D059811:HLA-DRB1 Chains; C497841:HLA-DRB1*01 antigen; C526364:HLA-DRB1*04:03 antigen; D010456:Peptides, Cyclic; C487763:cyclic citrullinated peptide; D012217:Rheumatoid Factor