cyclic citrullinated peptide antibody in serum; anti-citrulline antibody in serum; anti-CCP in serum

^[1]^[2]^[3]^[4]^[5]^[6]

Indications

70% sensitivity for RA; specificity for RA 95%
anti-CCP is less sensitive than rheumatoid factor (RF), but more specific for RA (95% vs 85-90%)*
may be elevated in rheumatoid factor-negative rheumatoid arthritis
anti-CCP positive in 40-60% of patients early in the course of RA when RF may be negative^[3]
presence of rheumatoid factor & anti-CCP Ab makes diagnosis of RA more likely^[5]
presence associated with erosions
predicts disease progression in undifferentiated arthritis^[3]
levels > 3-fold upper limit of normal associated with increased risk for development of rheumatoid arthritis^[6]

* anti-CCP Ab may occur in

↑ CCP Lab Tests Online: http://www.labtestsonline.org/understanding/analytes/ccp/glance.html
↑ Shmerling RH Testing for anti-cyclic citrullinated peptide antibodies: is it time to set this genie free? Arch Intern Med. 2009 Jan 12;169(1):9-14. Review. PMID: https://www.ncbi.nlm.nih.gov/pubmed/19139318
↑ ^3.0 ^3.1 ^3.2 Medical Knowledge Self Assessment Program (MKSAP) 14, 16, 17. American College of Physicians, Philadelphia 2006, 2012, 2015
↑ Whiting PF, Smidt N, Sterne JA et al Systematic review: accuracy of anti-citrullinated Peptide antibodies for diagnosing rheumatoid arthritis. Ann Intern Med. 2010 Apr 6;152(7):456-64; W155-66 PMID: https://www.ncbi.nlm.nih.gov/pubmed/20368651
↑ ^5.0 ^5.1 ^5.2 Veterans Administration
↑ ^6.0 ^6.1 Ford JA, Liu X, Marshall AA et al. Impact of cyclic citrullinated peptide antibody level on progression to rheumatoid arthritis in clinically tested cyclic citrullinated peptide antibody-positive patients without rheumatoid arthritis. Arthritis Care Res (Hoboken) 2019 Dec; 71:1583. PMID: https://www.ncbi.nlm.nih.gov/pubmed/30570827 https://onlinelibrary.wiley.com/doi/abs/10.1002/acr.23820