tailieunhanh - Patients With Pulmonary Tuberculosis Are Frequently Positive for Anti–Cyclic Citrullinated Peptide Antibodies, but Their Sera Also React With Unmodified Arginine-Containing Peptide

Anti–cyclic citrullinated peptide (anti-CCP) using a peptide of filaggrin has been used extensively as a new serologic marker of rheumatoid arthritis (RA) (1,2). Many studies have confirmed that anti-CCP enzymelinked immunosorbent assay (ELISA) is as sensitive as rheumatoid factor (RF) and much more specific for RA among various rheumatic diseases (2). However, anti- CCP in other diseases has been less well studied. Patients with certain infectious diseases, such as hepatitis C and tuberculosis (TB), can present with arthritis and frequently also have serum RF, making it difficult to distinguish infectious disease–related arthritis from RA. Thus, the utility of anti-CCP testing under these clinical circumstances is important. Studies in patients with hepatitis C viral infection. | ARTHRITIS RHEUMATISM Vol. 58 No. 6 June 2008 pp 1576-1581 DOI 2008 American College of Rheumatology Patients With Pulmonary Tuberculosis Are Frequently Positive for Anti-Cyclic Citrullinated Peptide Antibodies but Their Sera Also React With Unmodified Arginine-Containing Peptide Prasanthi Kakumanu 1 Hajime Yamagata 2 Eric S. Sobel 1 Westley H. Reeves 1 Edward K. L. Chan 1 and Minoru Satoh1 Objective. The anti-cyclic citrullinated peptide anti-CCP enzyme-linked immunosorbent assay ELISA has high sensitivity and specificity for rheumatoid arthritis RA . However detection of anti-CCP in patients with active pulmonary tuberculosis TB has recently been reported. To determine whether this activity was specific for the citrullinated residue the specificity of anti-CCP-positive sera for CCP versus that for unmodified arginine-containing peptide CAP was examined in patients with TB and compared with that in patients with RA. Methods. Anti-CCP and anti-CAP in sera from patients with pulmonary TB n 49 RA patients n 36 and controls n 18 were tested by ELISA. Sera were available at diagnosis from most TB patients. All TB patients were treated with a combination of 2-4 antibiotics for at least 6 months and sera were collected over time. Results. Anti-CCP was found in 37 of TB patients and in 43 of RA patients. CAP reactivity was more common in TB than in RA. High anti-CCP anti-CAP ratios were seen far more commonly in anti-CCP-positive RA patients than in anti-CCP-positive TB patients 94 versus 22 . Anti-CCP was inhibited by CCP peptide in sera from RA patients but not in sera from TB patients. A slight increase in Supported by the NIH grants R01-AR-40391 and M01-R-00082 and the Lupus Foundation of America. 1Prasanthi Kakumanu MD Eric S. Sobel MD PhD Westley H. Reeves MD Edward K. L. Chan PhD Minoru Satoh MD PhD University of Florida Gainesville 2Hajime Yamagata MD PhD National Hospital Organization Murayama Medical Center Musashi-Murayama Tokyo Japan. .