Objective: To identify the significance of serum cartilage oligomeric matrix protein (COMP), a marker of cartilage turnover, in patients with early-stage rheumatoid arthritis (RA) in relation to other serologic variables and magnetic resonance imaging (MRI) features.
Methods: Ninety-eight patients with early-stage RA, whose disease duration from onset was less than 2 years, were enrolled. The objective measures at baseline were Disease Activity Score (DAS28), serum C-reactive protein (CRP), serum matrix metalloproteinase-3 (MMP-3), serum antibodies against cyclic citrullinated peptide (anti-CCP), and MRI features of both wrist and finger joints. The MRI features included the number of sites scored positive for synovitis, bone edema, and bone erosion.
Results: Serum COMP concentration was not different among groups identified with low, moderate, and high DAS28-CRP values. However, COMP values were statistically high in subjects positive for bone erosions on MRI compared with the subjects who were negative for bone erosions. A positive correlation of COMP with CRP and with MMP-3 values was also identified.
Conclusion: Elevation of COMP may reflect joint damage that is dependent on the synovial inflammatory process in early-stage RA.