title: Anti-cyclic citrullinated peptide: diagnostic and prognostic values in juvenile idiopathic arthritis and rheumatoid arthritis in a Chinese population.
abstract: OBJECTIVE
  The incidence and clinical significance of anti-cyclic citrullinated peptide (CCP) antibodies in a cohort of Chinese patients with juvenile idiopathic arthritis (JIA) and adults with rheumatoid arthritis (RA) were studied.
  
  
  METHODS
  Anti-CCP antibodies were determined by enzyme-linked immunosorbent assay (ELISA) in 59 patients with JIA, 129 adult RA patients, 48 children with diseases other than JIA, 68 adult patients with rheumatic diseases other than RA, and 60 normal adults. Associations between anti-CCP antibodies and clinical and laboratory parameters were determined by Fisher's exact test.
  
  
  RESULTS
  Six of 59 (10.2%) patients with JIA and 71 of 129 (55%) patients with RA were positive for anti-CCP. Four of five RF-positive JIA patients and two of 54 RF-negative JIA patients were positive (p<0.001). One paediatric patient with allergy (0.9%) and two adult patients with rheumatic diseases other than RA (2.3%) were positive. All healthy controls were negative for anti-CCP. The specificity was 99.1% for JIA and 98.4% for RA. The sensitivity was 10.2% for JIA and 55% for RA. Positive predictive values were 85.7% for JIA and 97.3% for RA and negative predictive values were 66.9% for JIA and 68.5% for RA.
  
  
  CONCLUSIONS
  The anti-CCP antibody assay is a valuable tool for the diagnosis of RA and a subset of JIA in Chinese patients. It could be a useful predictive test for joint erosion in JIA of the polyarticular RF-positive subset and may be influential in the choice of the best therapeutic strategy in patients with recent-onset arthritis.
authors.affiliation: Department of Pathology, Queen Mary Hospital, Hong Kong, P.P.China. kwoksy@ha.org.hk
authors.forename: J S Y
authors.initials: JS
authors.lastname: Kwok
authors.forename: K H
authors.initials: KH
authors.lastname: Hui
authors.forename: T L
authors.initials: TL
authors.lastname: Lee
authors.forename: W
authors.initials: W
authors.lastname: Wong
authors.forename: Y L
authors.initials: YL
authors.lastname: Lau
authors.forename: R W S
authors.initials: RW
authors.lastname: Wong
authors.forename: D L
authors.initials: DL
authors.lastname: Kim
authors.forename: B M
authors.initials: BM
authors.lastname: Jones
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001171:Arthritis, Juvenile / Q000175:diagnosis* / Q000208:ethnology / Q000276:immunology*; D001172:Arthritis, Rheumatoid / Q000175:diagnosis* / Q000208:ethnology / Q000276:immunology*; D044466:Asian People; D001323:Autoantibodies / Q000097:blood; D015415:Biomarkers; D002648:Child; D002675:Child, Preschool; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D010456:Peptides, Cyclic / Q000276:immunology*; D011237:Predictive Value of Tests; D011379:Prognosis; D016036:Seroepidemiologic Studies
chemical_list: D001323:Autoantibodies; D015415:Biomarkers; D010456:Peptides, Cyclic; C487763:cyclic citrullinated peptide