The concentration of haptoglobin in synovial fluid of patients with rheumatoid arthritis

Abstract The low concentrations of haptoglobin found in “normal” synovial fluid suggested that the synovial membrane normally possesses a mechanism for specifically excluding this glycoprotein from the joint space. In patients with rheumatoid arthritis this mechanism is apparently at least partially blocked as evidenced by the marked increase in haptoglobin concentration relative to the increase in concentration of albumin and total proteins in the synovial fluid.