Alterations in human monocyte structure and function induced by incubation with gold sodium thiomalate.

The effect of in vitro indubation with gold sodium thiomalate (GST) on the morphology and functional activity of human mononuclear phagocytes (Mphi) was examined. Human peripheral blood Mphi that had been incubated with GST (25 micrograms/ml) for 4 days developed large intracytoplasmic vacuoles. Similar vacuolization developed after incubation with gold chloride but not with thiomalic acid. GST pre-incubation also induced a number of functional alterations in Mphi. GST incubation had little effect on glass adherence or FC receptor-mediated particle binding but markedly diminished pinocytosis of horseradish peroxidase and phagocytosis of IgG opsonized erythrocytes. These data indicate that the action of GST in rheumatoid arthritis may result from its capacity to alter the functional capability of Mphi.