title: The diagnostic value of anti-cyclic citrullinated peptide (CCP) antibodies in children with Juvenile Idiopathic Arthritis.
abstract: BACKGROUND
  Antibodies against cyclic citrullinated peptide (anti-CCP) are considered to be specific for rheumatoid arthritis (RA).
  
  
  OBJECTIVE
  To assess the clinical significance of anti-CCP antibodies in a cohort of patients with juvenile idiopathic arthritis (JIA) and if they can be used to identify patients with an unfavourable course of disease.
  
  
  METHODS
  68 serum samples were investigated. 45 patients were diagnosed with JIA (15 male and 30 female) aged 1.9-17.3 years (median 12.9 mean 11,0). 5 patients had polyarticular (RF negative), 2 polyarticular (RF positive), 25 oligoarticular JIA, 6 enthesitis related arthritis, 2 psoriatric arthritis, 3 patients had systemic disease and 2 unclassified arthritis. 23 samples were taken from patients with non-inflammatory cardiac diseases undergoing interventional cardiac therapy. Enzyme-linked immunosorbent assay (ELISA; Euroimmun, Lübeck, Germany) was used for the detection and quantification of anti-CCP antibodies in patients with JIA.
  
  
  RESULTS
  Overall, anti-CCP antibodies were found in 2.9% (2/68) of all samples and in 4.4 % (2/45) patients with JIA.
  
  
  CONCLUSIONS
  Anti-CCP antibodies are associated with RF positive polyarticular course of JIA. Anti-CCP antibodies are not relevant for other subgroups of JIA. Therefore anti-CCP Abs in patients with JIA should not be investigated routinely.
authors.affiliation: Department of Pediatrics, Innsbruck Medical School, Austria. juergen.brunner@uklibk.ac.at
authors.forename: J
authors.initials: J
authors.lastname: Brunner
authors.forename: F C
authors.initials: FC
authors.lastname: Sitzmann
mesh_terms: D000293:Adolescent; D001171:Arthritis, Juvenile / Q000175:diagnosis* / Q000276:immunology* / Q000503:physiopathology; D001323:Autoantibodies / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D010456:Peptides, Cyclic / Q000276:immunology*; D011237:Predictive Value of Tests
chemical_list: D001323:Autoantibodies; D015415:Biomarkers; D010456:Peptides, Cyclic; C487763:cyclic citrullinated peptide