[A new acute-phase protein. II. Quantitative determination in the serum of patients with rheumatoid arthritis]

An antigen (SF1 or TSGA) originally found in the inflammable synovial fluid of man, which comes from the cytoplasm of neutrophils, possesses the properties of an acute-phase-protein. The production of a specific antiserum against this antigen and the method of its quantitative determination by means of the Mancini-technique are described. In 89 sera of patients with rheumatoid arthritis the antigen was determined. First results of this investigation which speak for a dependence of the antigen concentration in the serum on activity and progression of the disease are reported.