CARTILAGE AND BONE MACROMOLECULES IN KNEE-JOINT SYNOVIAL-FLUID IN RHEUMATOID-ARTHRITIS - RELATION TO DEVELOPMENT OF KNEE OR HIP-JOINT DESTRUCTION

Objective-To examine the hypothesis that aggrecan, cartilage oligomeri c matrix protein (COMP), and bone sialoprotein (BSP) concentrations in synovial fluid could provide information on variations of progression of joint destruction in rheumatoid arthritis. Methods-Aggrecan, COMP, and BSP were quantified by enzyme linked immunosorbent assays in long itudinally collected knee joint synovial fluid samples of patients rap idly developing destruction in knees or hips, the ''destructive'' grou p, n = 18, and in patients slowly developing destruction, the ''non-de structive'' group, n = 25. Results-The aggrecan concentrations decreas ed from initially high levels (P << 0.001), and the BSP concentrations increased (P << 0.001) over time in the destructive group, whereas le vels of both markers were low and did not change in the non-destructiv e group. The COMP levels did not change in any of the groups. The aggr ecan concentrations were initially highest in the group developing des tructions (P << 0.001), whereas no difference between the groups was f ound regarding levels of COMP or BSP in the first sample. Conclusions- A destructive group was characterised by higher initial aggrecan conce ntrations and rising BSP concentrations in synovial fluid with time. Q uantification of cartilage and bone derived macromolecules contributes to the assessment of extent of tissue destruction and may help in the early identification of patients at risk of rapidly progressing destr uction.