%0 Journal Article %A Shuichiro Nakabo %A Hajime Yoshifuji %A Motomu Hashimoto %A Yoshitaka Imura %A Ran Nakashima %A Kosaku Murakami %A Nobuo Kuramoto %A Shinji Ito %A Junko Satoh %A Masao Tanaka %A Takao Fujii %A Tsuneyo Mimori %A Koichiro Ohmura %T Anti-carbamylated Protein Antibodies Are Detectable in Various Connective Tissue Diseases %D 2017 %R 10.3899/jrheum.161432 %J The Journal of Rheumatology %P 1384-1388 %V 44 %N 9 %X Objective. Anti-carbamylated protein (anti-CarP) antibodies are possible diagnostic biomarkers of anticitrullinated protein antibody (ACPA)-negative rheumatoid arthritis (RA). We aimed to elucidate the prevalence of anti-CarP antibodies in non-RA connective tissue diseases (CTD) because CTD are important in the differential diagnosis of ACPA-negative RA.Methods. The sera from 266 patients with RA and 616 patients with CTD and 80 healthy controls were examined using an in-house anti-CarP ELISA.Results. The prevalence and the level of anti-CarP antibodies in several CTD were comparable to those in ACPA-negative RA.Conclusion. Anti-CarP antibodies are not useful for differentiating ACPA-negative RA from CTD. %U https://www.jrheum.org/content/jrheum/44/9/1384.full.pdf