title: The diagnostic utilities of anti-agalactosyl IgG antibodies, anti-cyclic citrullinated peptide antibodies, and rheumatoid factors in rheumatoid arthritis.
abstract: The purpose of this study was to investigate the diagnostic utilities of anti-agalactosyl IgG antibody (CARF), anti-cyclic citrullinated peptide (CCP) antibody and rheumatoid factor (RF) in rheumatoid arthritis (RA), non-RA rheumatic diseases, and chronic viral hepatitis. The authors determined serum levels of CARF and anti-CCP2 by ELISA and IgM-RF by a immunonephelometric method in 834 controls and in 397 patients with the following conditions: RA (100), non-RA rheumatic diseases [systemic lupus erythematosus (SLE) 30, primary Sjogren's syndrome 18, systemic sclerosis 30, inflammatory myositis 19], chronic viral hepatitis B and C (HBV 100, HCV 100). The sensitivities of CARF (83%) and anti-CCP (85%) were significantly higher than that of RF (75%, p = 0.01, respectively) in RA, and the specificity of anti-CCP (98%) was significantly higher than those of CARF (92%) and RF (90%, p < 0.001, respectively). A comparison of receiver operating characteristic (ROC) curves revealed that the diagnostic accuracies of CARF and anti-CCP were superior to that of RF (CARF vs. RF, p = 0.008, anti-CCP vs. RF, p = 0.017) in RA. CARF positivity was significantly higher than those of anti-CCP (p = 0.007) and RF (p = 0.008) in systemic sclerosis, and the positivity of CARF was significantly higher than that of anti-CCP in Sjogren's syndrome (p = 0.016). Furthermore, CARF had significantly higher positivity than anti-CCP or RF in chronic viral hepatitis B and C. Finally, the titers of these three markers in RA were significantly higher than in non-RA rheumatic diseases and in chronic viral hepatitis B and C. Our results suggest that anti-CCP is the most useful serologic marker for the differentiation of RA and non-RA rheumatic diseases, and chronic viral hepatitis B and C.
authors.affiliation: Department of Internal Medicine, Seoul National University, College of Medicine, 28 Yongon-dong, Chongno-gu, Seoul, 110-744, Korea.
authors.forename: Hee Jung
authors.initials: HJ
authors.lastname: Ryu
authors.forename: Fujio
authors.initials: F
authors.lastname: Takeuchi
authors.forename: Shoji
authors.initials: S
authors.lastname: Kuwata
authors.forename: Yoon Jun
authors.initials: YJ
authors.lastname: Kim
authors.forename: Eun Young
authors.initials: EY
authors.lastname: Lee
authors.forename: Eun Bong
authors.initials: EB
authors.lastname: Lee
authors.forename: Yeong Wook
authors.initials: YW
authors.lastname: Song
mesh_terms: D000888:Antibodies, Anti-Idiotypic / Q000097:blood* / Q000276:immunology; D001172:Arthritis, Rheumatoid / Q000097:blood / Q000175:diagnosis* / Q000276:immunology; D015415:Biomarkers / Q000097:blood; D004797:Enzyme-Linked Immunosorbent Assay; D019694:Hepatitis B, Chronic / Q000097:blood / Q000175:diagnosis / Q000276:immunology; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology*; D010456:Peptides, Cyclic / Q000097:blood / Q000276:immunology*; D012372:ROC Curve; D012217:Rheumatoid Factor / Q000097:blood / Q000276:immunology*; D012595:Scleroderma, Systemic / Q000097:blood / Q000175:diagnosis / Q000276:immunology; D012859:Sjogren's Syndrome / Q000097:blood / Q000175:diagnosis / Q000276:immunology; D018709:Statistics, Nonparametric
chemical_list: D000888:Antibodies, Anti-Idiotypic; D015415:Biomarkers; D007074:Immunoglobulin G; D010456:Peptides, Cyclic; C064155:agalactosyl IGG; C487763:cyclic citrullinated peptide; D012217:Rheumatoid Factor