title: Diagnostic utility of anti-cyclic citrullinated peptide antibodies for rheumatoid arthritis in patients with active lung tuberculosis.
abstract: This study was intended to evaluate the utility of anti-cyclic citrullinated peptide antibodies (second generation, anti-CCP2) as a diagnostic marker for rheumatoid arthritis (RA) in patients with active tuberculosis. Among 89 patients with active tuberculosis, anti-CCP2 was detected in six (6.7%), and three of these (3.4%) were strongly positive for anti-CCP2. The positive rate of anti-CCP2 in patients with newly diagnosed RA was 82.1% (87 of 106 cases), while the rate in healthy control subjects was 0.4% (one of 237 individuals). The mean level of anti-CCP2 among the RA group was 159.3 U/ml, which was significantly higher than both that among the tuberculosis group (15.4 U/ml) and that among the healthy controls (0.7 U/ml). IgM rheumatoid factor (RF) was detected in 16 patients from the tuberculosis group (18.0%) with a mean serum level of 18.6 IU/ml and in 77 patients of the RA group (72.6%) with a mean level of 164.0 IU/ml. Only two cases in the tuberculosis group were positive for both anti-CCP2 and IgM RF. These observations show that measurement of anti-CCP2 seems to be a reliable serological tool for identifying early RA in patients with active tuberculosis.
authors.affiliation: Clinical Research Center for Rheumatic Disease and Department of Rheumatology, Kumamoto Saishunsou National Hospital, 2659 Suya, Kohshi, Kumamoto 861-1196, Japan. moris@saisyunsou1.hosp.go.jp
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Mori
authors.forename: Hiromichi
authors.initials: H
authors.lastname: Naito
authors.forename: Sumire
authors.initials: S
authors.lastname: Ohtani
authors.forename: Tohru
authors.initials: T
authors.lastname: Yamanaka
authors.forename: Mineharu
authors.initials: M
authors.lastname: Sugimoto
mesh_terms: D000328:Adult; D000368:Aged; D000888:Antibodies, Anti-Idiotypic / Q000097:blood* / Q000276:immunology; D001172:Arthritis, Rheumatoid / Q000097:blood / Q000150:complications / Q000175:diagnosis*; D015415:Biomarkers / Q000097:blood; D005260:Female; D006801:Humans; D007075:Immunoglobulin M / Q000097:blood; D008297:Male; D008875:Middle Aged; D010456:Peptides, Cyclic / Q000097:blood* / Q000276:immunology; D012217:Rheumatoid Factor / Q000097:blood; D012698:Serologic Tests / Q000379:methods; D014397:Tuberculosis, Pulmonary / Q000097:blood / Q000150:complications / Q000175:diagnosis*
chemical_list: D000888:Antibodies, Anti-Idiotypic; D015415:Biomarkers; D007075:Immunoglobulin M; D010456:Peptides, Cyclic; C487763:cyclic citrullinated peptide; D012217:Rheumatoid Factor