[Significance of anti-cyclic citrullinated peptide antibody and magnetic resonance imaging of metacarpophalangeal joints and wrist in early rheumatoid arthritis].

OBJECTIVE: To study the diagnostic value of anti-cyclic citrullinated peptide antibody (anti-CCP) and magnetic resonance imaging (MRI) of metacarpophalangeal joints (MCP) and wrist in early rheumatoid arthritis (RA).

METHODS: MRI of MCP and wrist joint, laboratory indices of anti-CCP and rheumatic factor (RF) were performed and recorded in the 94 early-stage RA patients, 24 non-typical monoarthritis and 35 other arthritis. The MRI findings and OMERACT (outcome measures in rheumatoid arthritis clinical trials) score were analyzed in comparison with their clinical and laboratory indices.

RESULTS: The sensitivity of anti-CCP, synovitis, bone erosion and bone erosion was 55.3%, 100%, 25.5% and 88.3% respectively in early-stage RA patients. The specificity was 88.6%, 71.4%, 94.3% and 65.7% respectively. There was significant difference between early-stage RA group and other arthritis group (P < 0.05). Bone erosion was found to be the most specific among MRI findings. And bone erosion of wrist joint had a positive correlation with anti-CCP. MRI was a more efficient supplemental modality in diagnosing early-stage RA as compared with conventional radiological films. Among 94 early-stage RA, their MRI findings and OMERACT scores of wrist joint appeared more obvious.

CONCLUSION: Anti-CCP has a better specificity for early-stage RA than RF. But MRI may visualize the disorder of RA earlier while it is often missed by radiological films. Both have prominent diagnostic values in early RA patients. Bone erosion of wrist joint has a positive correlation with anti-CCP. MRI may help to differentiate those RA patients with negative anti-CCP.