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

Abstract

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 ( p<0.01) 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 ( p<0.001) difference between the groups without and with radiological damage.

In the established RA group a significant ( p<0.01) 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.

• Anti-CCP antibodies
• Bone erosions
• Early rheumatoid arthritis
• Rheumatoid factors
• Anti-CCP, anti-cyclic citrullinated peptide antibodies
• RA, rheumatoid artritis
• RF, rheumatoid factor
• DAS 28, disease activity score
• JO, juxta-articular osteoporosis
• JE, joint erosions
• DMARDs, antirheumatic drugs
• SLE, systemic lupus erythematosus
• MCTD, mixed connective tissue disease
• SS, Sjögren syndrome
• PM, polymyositis
• SSc, systemic sclerosis
• other RD, osteoarthritis
• HD, healthy donors
• ANA, anti-nuclear antibodies
• LFT, latex fixation test
• IIF, indirect immunofluorescence
• ENA, anti-extractable nuclear antigen
• US, ultrasound
• MCP, metacarpophalangeae
• PIP, proximal interphalangeae
• DIP, distal interphalangeae