Cartilage matrix molecules in serum and synovial fluid.

The search continues for constituents of articular cartilage in the serum and synovial fluid of patients with arthritis. This work is driven by the hope that such "markers" will be useful in the diagnosis and management of rheumatic diseases. Absent information about the kinetics of these molecules continues to hinder interpretation of their concentration. Recent progress includes recognition of markers that appear to be specific for diseased cartilage and identification of factors that may distinguish between reversible and irreversible disease.