The detecting and clinical value of anti-cyclic citrullinated peptide antibodies in patients with systemic lupus erythematosus

The aim of this article is to compare the prevalence of anti-cyclic citrullinated peptide (anti-CCP) antibodies in systemic lupus erythematosus (SLE) patients with and without arthritis and in patients with rheumatoid arthritis (RA). Anti-CCP antibodies were measured using ELISA in 159 SLE patients with arthritis (12 patients with erosive arthritis), 108 SLE patients without arthritis, 76 RA patients, and 87 healthy subjects (controls). The following had anti-CCP antibodies above the cut-off level (5 U/ml): 27.3% of SLE patients, 42.1% SLE patients with arthritis, 5.6% SLE patients without arthritis, 85.5% RA patients and 1.1% controls. The mean titre of anti-CCP antibodies in the SLE group was much lower than that in the RA group (33 +/- 72 vs. 160 +/- 125 U/ml), but higher in SLE patients with erosive arthritis than those with non-erosive arthritis (221 +/- 88 vs. 32 +/- 42 U/ml). Hand poly-arthritis occurred more frequently in anti-CCP-positive SLE patients with erosive arthritis than those with non-erosive arthritis. Anti-CCP antibodies were prevalent in some SLE patients, more prevalent in SLE patients with arthritis than those without arthritis. Anti-CCP-positive SLE patients were more likely associated with hand poly-arthritis, and high titre of anti-CCP antibodies might be used as a predictor for the complication of erosive arthritis. Lupus (2009) 18, 713-717.