Deposition of fibrinogen (FR-antigen) in skin diseases. III. Synovial joint membranes in psoriatic arthritis.

Synovial joint membranes obtained by synovectomy in open bloodless fields were examined for FR-antigen (fibrinogen/fibrin-related antigen) in 15 patients with psoriatic arthritis (ps.a.) and in a control group of 5 patients with meniscal tears. All frozen and paraffin sections from ps.a. demonstrated FR-antigen at the synovial lining. In the tissue it was located at the surface and in cytoplasm of the superficial synovial cells. In the control group, FR-antigen was present in all frozen samples as a thin layer at the synovial lining surface, but absent in the paraffin sections. The presence of FR-antigen may contribute to the further development of the Inflammatory changes of the arthritis.