Role of anti-CCP in arthritis in patients with systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease with multi-organ involvement. Patients with SLE feature a lower tendency to develop erosive arthritis in comparison with rheumatoid arthritis (RA); however, in some arthritis cases it may be difficult to differentiate SLE from RA. Anti-cyclic citrullinated peptide (Anti-CCP) antibodies are highly-specific for RA. The current study evaluated the relationship between anti-CCP and arthritis in SLE patients. In this study, anti-CCP antibodies were tested in 300 patients with SLE. The INOVA Diagnostics QUANTA Lite™ CCP IgG ELISA and the Axis-Shield Diagnostics Diastat™ anti-CCP ELISA test were applied. Patients were divided into two groups: those with and those without arthritis. Patients with chronic arthritis (> 6 weeks) had radiography done on the involved joints. Chi square and Fisher’s exact tests were applied to compare the two subsets. Anti-CCP antibodies were detected in 4.7% of all patients (CI: 2.6-7.8). Anti-CCP was positive in 6.4% of patients with arthritis and 2.3% of patients without arthritis (P=0.09). From seven patients with chronic arthritis, one had both positive anti-CCP and erosions. In the studied Iranian SLE patients, anti-CCP levels were higher in patients with arthritis than in those without arthritis. This study did not show any association of anti-CCP with erosion in SLE patients with arthritis. Ethnic and geographical variance may have influenced the results. More studies on chronic arthritis in SLE are needed to confirm this hypothesis.

Keywords:

Anti-CCP , arthritis , arthropathy , Systemic lupus erythematosus