title: Contribution of anti-cyclic citrullinated peptide antibody and rheumatoid factor to the diagnosis of arthropathy in haemochromatosis.
abstract: OBJECTIVE
  To investigate the prevalence of antibodies to cyclic citrullinated peptide (anti-CCP) and rheumatoid factor in patients with hereditary haemochromatosis (HHC) and to evaluate their diagnostic reliability in distinguishing HHC-associated arthropathy from rheumatoid arthritis.
  
  
  METHODS
  Anti-CCP antibodies and rheumatoid factor levels were determined by ELISA in sera from 87 patients with HHC homozygous for the C282Y mutation of the HFE gene, 31 patients with rheumatoid arthritis and 162 healthy controls.
  
  
  RESULTS
  Of the 87 patients with HHC, 32 (36.8%) had joint involvement. Anti-CCP antibodies were detected in only 1 patient (1.1%) with HHC, who had no joint disease, and in (1.2%) healthy controls. In total, 18 (58.1%) patients with rheumatoid arthritis displayed anti-CCP reactivity (p<0.001). Rheumatoid factor was detected in 10 (11.5%) patients with HHC compared with 7 (4.3%) healthy control subjects (p = 0.03) and 21 of 31 (65.6%) patients with rheumatoid arthritis.
  
  
  CONCLUSIONS
  Testing for anti-CCP antibodies discriminates HHC arthropathy from rheumatoid arthritis, as these patients were consistently anti-CCP negative. Thus, HHC arthropathy should be considered in the differential diagnosis of CCP-negative arthritis.
authors: Department of Internal Medicine, General Hospital Oberndorf, Teaching Hospital of Paracelsus Medical University Salzburg, Oberndorf, Austria.
authors: E
authors: E
authors: Aigner
authors: I
authors: I
authors: Schmid
authors: C H
authors: CH
authors: Osterreicher
authors: J
authors: J
authors: Zwerina
authors: G
authors: G
authors: Schett
authors: M
authors: M
authors: Strasser
authors: F
authors: F
authors: Niksic
authors: F
authors: F
authors: Hohla
authors: T
authors: T
authors: Ramsauer
authors: U
authors: U
authors: Dorn
authors: W
authors: W
authors: Patsch
authors: C
authors: C
authors: Datz
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000175:diagnosis / Q000276:immunology; D001323:Autoantibodies / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D003937:Diagnosis, Differential; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006432:Hemochromatosis / Q000097:blood* / Q000150:complications / Q000276:immunology; D000071020:Hemochromatosis Protein; D015395:Histocompatibility Antigens Class I / Q000235:genetics; D006720:Homozygote; D006801:Humans; D007592:Joint Diseases / Q000097:blood* / Q000209:etiology / Q000276:immunology; D008297:Male; D008565:Membrane Proteins / Q000235:genetics; D008875:Middle Aged; D010456:Peptides, Cyclic / Q000276:immunology*; D017354:Point Mutation; D015995:Prevalence; D012217:Rheumatoid Factor / Q000097:blood*; D012680:Sensitivity and Specificity
chemical_list: D001323:Autoantibodies; D015415:Biomarkers; C103673:HFE protein, human; D000071020:Hemochromatosis Protein; D015395:Histocompatibility Antigens Class I; D008565:Membrane Proteins; D010456:Peptides, Cyclic; C487763:cyclic citrullinated peptide; D012217:Rheumatoid Factor