Anti-cyclic Citrullinated Peptide Antibodies are Highly Associated with Severe Bone Lesions in Rheumatoid Arthritis Anti-CCP and Bone Damage in RA

In the present study we investigated the predictive value of anti-cyclic citrullinated peptide antibodies (anti-CCP) in early rheumatoid arthritis (RA) with respect to the bone damage. Fifty-four patients with early RA (onset <12 months), 35 classified as established RA (onset >12 months), 33 healthy donors and 76 non-RA autoimmune diseases, were enrolled. Anti-CCP and IgG, IgA, IgM rheumatoid factors (RFs) were determined at baseline. Disease activity score (DAS 28) was calculated at the entry. Bone involvement was evaluated by X-rays and sonography. The specificity of anti-CCP was 98.4%; significantly higher than those of the IgM- (86.0%), IgA- (86.0%) and IgG-RFs (66.2%), respectively. Anti-CCP were detected in 23/54 (42.6%) early RA patients and in 16/35 (45.7%) established RA patients. In the early RA group, 6/33 (18.2%) of the patients without bone lesions, 12/16 (75%) with juxta-articular osteoporosis (JO) and 5/5 with joint erosions (JE) resulted positive showing a significant difference between the groups without and with radiological damage. In the established RA group a significant difference being between the group without radiological damage and that with JE was found. Finally, in patients without radiological lesions, examined by ultrasound, anti-CCP antibodies were detected only in subjects with pathologic findings (31.25%). Data here reported confirm that the presence of anti-CCP are specific for diagnosis of RA, of recent onset also and they are potentially useful as prognostic index of bone involvement.