Erosive arthritis in systemic lupus erythematosus is associated with high serum C-reactive protein and anti-cyclic citrullinated peptide antibodies

Predictors for erosive arthritis in systemic lupus erythematosus (SLE) are poorly understood. We performed a pilot, descriptive case-series study to identify whether different biomarkers differentiate SLE patients from those additionally developing erosive arthritis. Median C-reactive protein (CRP) concentration in erosive arthritis was 14.5 mg/L (IQR, 6.6-19.4), but only 0.8 (0.45-7.37, p = 0.01) in non-erosive. Anti-cyclic citrullinated peptide antibodies (anti- CCP) were also associated with erosive arthritis (60 vs. 0% , p = 0.02; OR = 18.2, 0.66-495). Serum IL-6, IFN gamma, IL-4 and IL-10 tended to be higher in erosive arthritis, although none attained statistical significance. A negative correlation between IL-6 and CRP was found in non-erosive arthritis ( r-0.60). High CRP and anti-CCP may be useful serological markers for an erosive arthritis pattern among SLE patients.