ABERRANT PRODUCTION OF GLIOSTATIN PLATELET-DERIVED ENDOTHELIAL-CELL GROWTH-FACTOR IN RHEUMATOID SYNOVIUM

Objective. To purify a protein inhibitor from rheumatoid arthritis (RA ) synovial fluids which suppresses the apparent incorporation of H-3-t hymidine into fibroblasts and synovial cells, and to define its bioche mical features that have clinical relevance to the pathogenesis of RA. Methods. Several standard chromatographic techniques were employed fo r the purification of the protein. Immunochemical methods with monoclo nal antibody were used to quantify and visualize the protein in sera, synovial fluids, and tissues from RA patients. Results. The chemical p roperties of purified inhibitor from RA synovial fluids confirmed its identity as gliostatin/platelet-derived endothelial cell growth factor (PD-ECGF), a potent angiogenic factor. The gliostatin/PD-ECGF level i n synovial fluid and serum was higher in RA patients than in osteoarth ritis controls. Conclusion. These findings strongly suggest that glios tatin/PD-ECGF might play an important role in the aberrant neovascular ization of rheumatoid synovium.