Biochemical markers of joint tissue turnover in early rheumatoid arthritis.
The progression of rheumatoid arthritis (RA), a disease characterized by synovitis, cartilage degradation and bone erosion, is highly variable from patient to patient. New specific biological markers reflecting quantitative and dynamic changes in joint tissue turnover have been recently developed and include assays for type II collagen synthesis and degradation and synovitis. Increasing evidence from prospective studies in early RA indicate that some of these markers may be useful to predict the progression and identify patients at risk for rapid joint damage, before any damage is detected by radiography. Although studies on their value in assessing the efficacy of treatments are still limited, preliminary data in early RA suggest that biological markers will play an important role in the development and the early monitoring of disease modifying antirheumatic drugs with respect to future radiographic progression.