Anti-CCP: challenges in quantifying auto-antibodies and creating international reference materials.

Abstract

Anti-CCP assays (antibody to cyclic citrullinated peptides) possess a high specificity for RA (rheumatoid arthritis). In lack of an international reference material the absolute values among different assays strongly diversify. The cut-off showed a variance from 5 U/mL Euroimmun anti-CCP to 25 U/mL Euro-Diagnostica Immunosan RA. The Autoantibody Standardization Committee is currently trying to establish a reference specimen of human polyclonal anti-CCP.