Synonyms: ANTI-CCP
Related tests: Antinuclear antibodies

Clinical significanceClinical indicationsSample typePreparationNotes

Clinical significance
Anti-citrulline antibodies are used in the diagnosis of rheumatoid arthritis (RA). They are directed against the citrullinated residues of the protein filaggrin (cyclic citrullinated peptide) and are certainly more specific than the now outdated rheumatoid factor test and Waaler-Rose test. They are found in 60-80% of patients with RA and in 30% of patients who are negative for rheumatoid factor. They also have two important features: they are present in the early, subclinical stages of the disease, making them useful for early diagnosis, and they also have value as a prognostic marker of how the disease will develop.

Clinical indications
Rheumatoid arthritis

Sample type
The patient must have a blood sample taken.

Preparation
You must fast for at least 8 hours; a small amount of water is allowed. You must have been standing or sitting upright for at least 30 minutes.

Notes
They may be present in connective tissue diseases, especially SLE.

  • Values of 20-34 U/ml should be considered weakly positive
  • Values of 40-59 moderately positive
  • Values of 60 U/ml or more strongly positive.