Anticyclic citrullinated peptide autoantibodies in systemic lupus erythematosus

Abstract

Systemic lupus erythematosus is an autoimmune disease with protean manifestation. Arthritis is one of the most common manifestations seen in SLE. Anti-CCP Ab is a recently described autoantibody that has been claimed as a most sensitive and specific marker for the diagnosis of RA. Study was performed to see whether anti-CCP2 Ab is positive in lupus arthritis or not. Anti-CCP Ab, ANA, ds DNA, and APLA were estimated by ELISA. Anti-CCP2 Ab was positive in 22 cases (37.93%) of SLE. Mean value of anti-CCP (18.08 ± 16.95 U/ml) was statistically significant (P < 0.001) when compared to control (5.07 ± U/ml). A total of 44 (75.86%) patients with SLE had arthritis. In 29 (50.00%) cases, arthritis resembled RA along with classical features of SLE, while 15 cases (25.86%) had nonspecific lupus arthritis. In 13 cases (44.82%) of RA type lupus arthritis, anti-CCP2 Ab was positive, while only three (20%) nonspecific lupus arthritis cases had elevated anti-CCP. In 14 (24.13) patients with SLE, there was no arthritis, but in this group also (6/14) 42.85% cases had elevated anti-CCP. A total of 11 (50%) patients with duration less than 1 year had more anti-CCP 2 positivity when compared to disease duration between 1 and 3 years (27.27%) and disease duration more than 3 years (22.72%), but specifically, it was not significant. Our study concludes that anti-CCP2 is not a specific antibody for RA, but it is present in autoimmune diseases. © 2010 Springer-Verlag.