@article {Zhaojrheum.100399, author = {Jinxia Zhao and Xiangyuan Liu and Zhimin Wang and Rui Liu and Zhanguo Li}, title = {Is It Necessary to Combine Detection of Anticitrullinated Protein Antibodies in the Diagnosis of Rheumatoid Arthritis?}, elocation-id = {jrheum.100399}, year = {2010}, doi = {10.3899/jrheum.100399}, publisher = {The Journal of Rheumatology}, abstract = {Objective Antibodies against citrulline-containing epitopes, such as antiperinuclear factor (APF), antikeratin antibodies (AKA), antifilaggrin antibodies, and anticyclic citrullinated peptide (anti-CCP) antibodies, are specific in rheumatoid arthritis (RA). Detection of APF, AKA, and anti-CCP has been widely used in clinical practice. However, studies on combined detection of these anti- citrullinated protein antibodies (ACPA) in the significance of diagnosing RA have been limited. We aimed to detect APF, AKA, and anti-CCP antibodies and to evaluate the significance of combined detection of these ACPA in RA. Methods A total of 551 patients with arthritic disorders, 304 with RA and 247 with other rheumatic diseases, were selected at the Department of Rheumatology and Immunology during the past 2 years. AKA and APF were tested by indirect immunofluorescence assay. Anti-CCP was detected using the second-generation ELISA kit. Results The sensitivities of anti-CCP, AKA, and APF tests for RA were 76.2\%, 43.4\%, and 34.5\%, respectively, while the specificities were 96.0\%, 98.4\%, and 99.6\%. The combination of anti-CCP, AKA, and APF positivity had the highest specificity (100\%), but it yielded a low sensitivity (28.3\%). When 2 of the 3 ACPA were positive, the sensitivity and specificity were 48.4\% and 99.2\%, respectively. When either anti-CCP or AKA or APF was positive, sensitivity increased to 77.3\%, but specificity decreased to 94.7\%. Conclusion Anti-CCP was the most valuable marker in the diagnosis of RA, among the 3 ACPA. Combined detection of anti-CCP, AKA, and APF did not increase the diagnostic capability for RA.}, issn = {0315-162X}, URL = {https://www.jrheum.org/content/early/2010/10/13/jrheum.100399}, eprint = {https://www.jrheum.org/content/early/2010/10/13/jrheum.100399.full.pdf}, journal = {The Journal of Rheumatology} }