title: Anti-cyclic citrullinated peptide (anti-CCP) antibodies in children with juvenile idiopathic arthritis.
abstract: OBJECTIVE
  To determine if anti-cyclic citrullinated peptide antibodies (anti-CCP) can be detected in sera of patients with juvenile idiopathic arthritis (JIA) and if they can be used to identify patients with a more destructive course of disease.
  
  
  METHODS
  One hundred serum samples of 71 patients with JIA taken at different time points in their disease course were analyzed by a commercially available anti-CCP ELISA. Followup serum samples from 28 patients were also tested. Correlations between anti-CCP and disease characteristics, medication, and radiological damage (presence of joint space narrowing and/or erosions) were also determined.
  
  
  RESULTS
  The serum samples came from patients of all 8 different subtypes of JIA (mean age: 9.6 years, median: 10.5; disease duration mean: 39 months, median: 24) including 11 polyarticular rheumatoid factor positive (IgM-RF) patients. Anti-CCP was positive in 73% of the IgM-RF positive JIA patients and in 3% of the other JIA patients (p < 0.0001). Disease duration, medication, and anti-nuclear antibody positivity did not differ significantly between anti-CCP positive and negative patients. Testing of followup samples showed almost identical anti-CCP results. All IgM-RF positive JIA patients had radiological damage (p < 0.001). Of the anti-CCP positive patients, 80% had radiological damage resulting in a significant difference between anti-CCP positive and negative patients (p = 0.009) with an odds ratio (OR) of 12.7, but corrected for IgM-RF, the OR was no longer significant (p = 0.88).
  
  
  CONCLUSIONS
  Anti-CCP antibodies can be detected in the sera of patients with JIA but almost exclusively in the subset of patients with polyarticular IgM-RF.
authors.affiliation: Department of Pediatrics, Leiden University Medical Center, Leiden, The Netherlands. m.van_rossum@lumc.edu
authors.forename: Marion
authors.initials: M
authors.lastname: van Rossum
authors.forename: Renée
authors.initials: R
authors.lastname: van Soesbergen
authors.forename: Sandra
authors.initials: S
authors.lastname: de Kort
authors.forename: Rebecca
authors.initials: R
authors.lastname: ten Cate
authors.forename: Aeilko H
authors.initials: AH
authors.lastname: Zwinderman
authors.forename: Ben
authors.initials: B
authors.lastname: de Jong
authors.forename: Ben
authors.initials: B
authors.lastname: Dijkmans
authors.forename: Walther J
authors.initials: WJ
authors.lastname: van Venrooij
mesh_terms: D000293:Adolescent; D000328:Adult; D000906:Antibodies / Q000097:blood*; D001171:Arthritis, Juvenile / Q000175:diagnosis / Q000276:immunology*; D015415:Biomarkers; D002648:Child; D002675:Child, Preschool; D002956:Citrulline / Q000276:immunology*; D018450:Disease Progression; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007075:Immunoglobulin M / Q000097:blood; D010456:Peptides, Cyclic / Q000276:immunology*; D011237:Predictive Value of Tests; D012217:Rheumatoid Factor / Q000276:immunology
chemical_list: D000906:Antibodies; D015415:Biomarkers; D007075:Immunoglobulin M; D010456:Peptides, Cyclic; D002956:Citrulline; D012217:Rheumatoid Factor