Difference in cartilage proteoglycan level in synovial fluid in early rheumatoid arthritis and reactive arthritis.
Cartilage proteoglycans were measured, by the use of an enzyme-linked immunosorbent assay, in synovial fluids obtained from 109 unselected patients attending an outpatient rheumatology clinic because of inflammation of the knee. The content of proteoglycans in synovial fluid was inversely related to the degree of joint destruction shown on X-ray. The proteoglycan concentrations in knee-joint exuda