title: Anti-CCP antibodies are associated with early age at onset in patients with rheumatoid arthritis.
abstract: OBJECTIVE
  To determine factors influencing the age at onset of rheumatoid arthritis (RA).
  
  
  METHODS
  A sample of 152 Colombian patients was investigated. Hazard ratios (HRs) that measured the effect size of risk factors on the age at RA onset were computed by using Cox regression models.
  
  
  RESULTS
  Positive anti-CCP antibodies were associated with an increased risk of early RA onset (HR = 1.60; 95% confidence interval, [1.06, 2.4]), whereas the presence of the protective (70)DERAA(74) sequence was associated with a delayed onset (HR = 0.55; [0.33, 0.92]). After controlling for both anti-CCP antibodies and the (70)DERAA(74) sequence, the following variables did not influence significantly the age at RA onset: gender, ever cigarette smoking, family RA history, the TNF-308 A polymorphism, HLA shared epitope, and the presence of rheumatoid factor.
  
  
  CONCLUSIONS
  Anti-CCP antibodies and the HLA-DRB1 (70)DERAA(74) sequence influence the age at onset of RA.
authors.affiliation: Department of Biostatistics, the University of Kansas Medical Center, Kansas City, United States.
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Diaz
authors.forename: Adriana
authors.initials: A
authors.lastname: Rojas-Villarraga
authors.forename: Juan C
authors.initials: JC
authors.lastname: Salazar
authors.forename: Antonio
authors.initials: A
authors.lastname: Iglesias-Gamarra
authors.forename: Ruben D
authors.initials: RD
authors.lastname: Mantilla
authors.forename: Juan-Manuel
authors.initials: JM
authors.lastname: Anaya
mesh_terms: D000328:Adult; D017668:Age of Onset; D000888:Antibodies, Anti-Idiotypic / Q000097:blood*; D001172:Arthritis, Rheumatoid / Q000453:epidemiology* / Q000235:genetics / Q000276:immunology*; D003105:Colombia; D005260:Female; D006684:HLA-DR Antigens / Q000235:genetics; D059811:HLA-DRB1 Chains; D006801:Humans; D008297:Male; D008875:Middle Aged; D010456:Peptides, Cyclic / Q000276:immunology*; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D012044:Regression Analysis; D012189:Retrospective Studies; D012307:Risk Factors
chemical_list: D000888:Antibodies, Anti-Idiotypic; D006684:HLA-DR Antigens; D059811:HLA-DRB1 Chains; D010456:Peptides, Cyclic; C487763:cyclic citrullinated peptide