Tissue-derived macromolecules and markers of inflammation in serum in early rheumatoid arthritis: relationship to development of joint destruction in hands and feet

We have previously shown that serum concentrations of cartilage oligomeric matrix protein (COMP) are increased early in rheumatoid arthritis (RA) patients who subsequently develop advanced large-joint destruction. A prognostic value for joint damage of serum concentrations of hyaluronan (HA) is also suggested by previous studies. In contrast, serum concentrations of bone sialoprotein (BSP) have not been useful for identifying patients with progressive large-joint destruction. In the present study, we have examined the hypothesis that serum concentrations of these tissue-derived markers are of prognostic value in RA for the development of radiographically detectable joint damage in hands and feet. Serum concentrations of COMP, HA and BSP were quantified in samples obtained from 62 patients within the first year after onset of RA and were related to the development of radiographically detectable damage in these joints after 5 yr. Neither the serum concentrations of COMP nor of BSP at inclusion predicted joint damage in hands and feet after 5 yr, and the concentration of these proteins did not change over the 5 yr period. However, the serum concentration of HA at inclusion correlated with the radiographic score at the 5 yr follow-up (r = 0.425, P < 0.01), but was not a better predictor in this respect than the erythrocyte sedimentation rate or C-reactive protein levels at inclusion. Thus, serum concentrations of the three studied tissue-derived macromolecules were in this study not useful for identifying patients prone to small-joint destruction.