ABSTRACT
Objective To study the association of serum cartilage oligomeric matrix protein (COMP)with disease activity and early joint destruction of rheumatoid arthritis (RA). Methods The serum levels of COMP were measured with ELISA in 94 patients with RA and 40 controls. The serum level of erythrocyte sedimentation rate (ESR), rheumatoid factor (RF), anti-cyclic citrullinated peptide antibodies (ACCP) and hand X-ray were examined at the same time. Results Significantly increased serum level of COMP was found in RA patients (11.3±5.2) U/L as compared to that in healthy controls (9.2±1.7) U/L (P=0.017).Serum level of COMP was higher in 64 active patients (14±6) U/L than that in 30 inactive disease (9±4) U/L(P=0.005). COMP level was positively correlated with the number of the affected joints, X-ray stage, CRP and ESR level (P<0.05); but had no correlation with age, disease course, grade of joint function, RF and ACCP levels. Thirty patients were followed for two years and their radiographic changes were evaluated at the baseline and the end of this study. Sixteen of 18 patients with high concentration serum COMP level had radi-ologic progression, but only 5 of 12 patients with no increase of serum COMP had radiologic progression. A significant difference (P=0.013) was founded in the two groups. Conclusion The present data suggests that the level of COMP is high in patients with RA. High serum levels of COMP indicate high disease activity and early progressive of bone destruction in RA patients. We can us COMP as a laboratory marker of RA.