Metabolic and secretory properties of peripheral and synovial granulocytes in rheumatoid arthritis

The metabolic and secretory properties of peripheral and synovial granulocytes of patients with rheumatoid arthritis were investigated with serum- or immunoglobulin-treated zymosan as activators of cell metabolism. During isolation of the synovial cells precautions were taken to prevent in vitro phagocytosis of immune materials present in the synovial fluids. Oxygen uptake, extracellular release of lysosomal enzymes under resting and activated conditions, yield of the isolated granulocytes, and the granule enzyme content of peripheral and synovial cells did not differ significantly from those of peripheral granulocytes from healthy volunteers. In agreement with the biochemical results, intracellular inclusions could be detected in only a few synovial cells with a direct immunofluorescence technique. The possibility that formation of "ragocytes" may be an in vitro phenomenon is discussed.