The occurrence of cryoproteins in synovial fluid; the association of a complement-fixing activity in rheumatoid synovial fluid with cold-precipitable protein

Abstract

A B S TR A C T A significant portion of a complementfixing activity found in the synovial fluid of patients with rheumatoid arthritis, and previously implicated as a possible cause of the low synovial fluid complement levels in these patients behaves as a high solubility cryoprotein. Analysis of rheumatoid synovial fluid cryopro- teins has revealed mixed immunoglobulins, bound com- plement components, fibrinogen, DNA, and rheumatoid factor.