Anti–citrullinated protein antibody
Anti-citrullinated protein antibodies (ACPAs) are autoantibodies (antibodies to an individual's own proteins) that are directed against peptides and proteins that are citrullinated. They are present in the majority of patients with rheumatoid arthritis. Clinically, cyclic citrullinated peptides (CCP) are frequently used to detect these antibodies in patient serum or plasma (then referred to as anti–citrullinated peptide antibodies).[1]
During inflammation, arginine amino acid residues can be enzymatically converted into citrulline residues in proteins such as vimentin, by a process called citrullination. If their shapes are significantly altered, the proteins may be seen as antigens by the immune system, thereby generating an immune response.[2]
ACPAs have proved to be powerful biomarkers that allow the diagnosis of rheumatoid arthritis (RA) to be made at a very early stage.[1] In July 2010, the 2010 ACR/EULAR Rheumatoid Arthritis Classification Criteria were introduced.[3] These new classification criteria include ACPA testing, and overruled the "old" ACR criteria of 1987 and are adapted for early RA diagnosis.
- ^ a b Puszczewicz M, Iwaszkiewicz C (May 2011). "Role of anti-citrullinated protein antibodies in diagnosis and prognosis of rheumatoid arthritis". Arch Med Sci. 7 (2): 189–94. doi:10.5114/aoms.2011.22067. PMC 3258718. PMID 22291756.
- ^ Raptopoulou A, Sidiropoulos P, Katsouraki M, Boumpas DT (2007). "Anti-citrulline antibodies in the diagnosis and prognosis of rheumatoid arthritis: evolving concepts". Crit Rev Clin Lab Sci. 44 (4): 339–63. doi:10.1080/10408360701295623. PMID 17558653. S2CID 1773519.
- ^ Aletaha D, Neogi T, Silman AJ, et al. (September 2010). "2010 rheumatoid arthritis classification criteria: an American College of Rheumatology/European League Against Rheumatism collaborative initiative" (PDF). Ann. Rheum. Dis. 69 (9): 1580–8. doi:10.1136/ard.2010.138461. PMID 20699241. S2CID 1191830.