We aimed to investigate the relationship between anti-cyclic citrullinated peptide (anti-CCP) levels and bone mineral density (BMD), bone turnover, and radiographic damage in patients with rheumatoid arthritis (RA).
Eighty patients (68 females, 12 males, mean age 46.50+/-14.59 years) with RA were included in the study. Anti-CCP antibodies were measured by enzyme-linked immunosorbent assay (ELISA). Bone turnover was studied by analysing serum levels of C-terminal telopeptide of type I collagen (sCTX, ng/mL), using an enzyme immunoassay. BMD was measured by dual-energy X-ray absorptiometry (DXA). Disease activity was assessed according to the Disease Activity Score that includes 28 joint counts (DAS28). Functional capacity was assessed by the Health Assessment Questionnaire (HAQ).
Anti-CCP-positive patients were defined as group 1 and anti-CCP-negative patients as group 2. The mean disease duration was 7.53+/-6.27 years in group 1 and 6.25+/-6.51 years in group 2. Anti-CCP had a limited negative correlation with lumbar BMD (r = -0.220, p = 0.050) and a negative correlation with femoral BMD (r = -0.242, p = 0.031). There was no statistically significant correlation between anti-CCP and sCTX values (r = 0.117, p = 0.301). Sharp scores were significantly higher in anti-CCP-positive than anti-CCP-negative patients (p = 0.012), and anti-CCP levels were significantly correlated with Sharp scores (r = 0.240, p = 0.032).
We found that RA patients with higher levels of anti-CCP antibody had lower lumbar and femoral BMD. Anti-CCP levels were also associated with radiographic damage. Therefore, we suggest that anti-CCP may be a determinant of bone loss in patients with RA.