Clinical utility of the anti-CCP assay: experiences with 700 patients

Ann N Y Acad Sci. 2005 Jun;1050:314-8. doi: 10.1196/annals.1313.033.


Our objective was to determine the frequency of antibodies to cyclic citrullinated peptides (CCPs) in a series of patients with a variety of rheumatic diseases. Seven hundred consecutive serum samples from patients at an outpatient clinic were tested for the presence of rheumatoid factor (RF) and anti-CCP. Clinical diagnosis, radiographic information, and other laboratory data were taken from patients' charts. The sensitivity and specificity of anti-CCP reactivity for the diagnosis of rheumatoid arthritis (RA) were 74.0% and 94.5%, respectively; the corresponding results for RF were 69.7% sensitivity and 81.0% specificity. Highest rates of false-positive RF tests were found in patients with SLE (18.3% vs. 12.7% CCP), Sjögren's syndrome (73.3% vs. 3.3% CCP), and a control group with chronic hepatitis (24.7% vs. 1.3% CCP). The detection of anti-CCP is useful for the diagnosis of RA because of its similar sensitivity but higher specificity compared with RF. Anti-CCP also helps to diagnose other inflammatory and noninflammatory diseases (especially connective tissue diseases) by reducing the rate of false-positive results in comparison with RF.

MeSH terms

  • Arthritis, Rheumatoid / diagnosis
  • Arthritis, Rheumatoid / diagnostic imaging
  • Arthritis, Rheumatoid / immunology
  • Autoantibodies / blood*
  • Biomarkers / blood
  • Citrulline / immunology*
  • Cohort Studies
  • Diagnosis, Differential
  • Enzyme-Linked Immunosorbent Assay
  • False Positive Reactions
  • Humans
  • Nephelometry and Turbidimetry
  • Outpatient Clinics, Hospital
  • Outpatients
  • Peptides, Cyclic / immunology*
  • Radiography
  • Rheumatic Diseases / diagnosis*
  • Rheumatic Diseases / diagnostic imaging
  • Rheumatic Diseases / immunology
  • Rheumatoid Factor / blood
  • Sensitivity and Specificity


  • Autoantibodies
  • Biomarkers
  • Peptides, Cyclic
  • Citrulline
  • Rheumatoid Factor