Gold-induced changes in the morphology and functional capabilities of human monocytes.

The capacity of gold compounds to induce morphologic changes and alterations in the functional activity of human mononuclear phagocytes (M phi) in vitro was examined. Human peripheral blood mononuclear cells were incubated with gold sodium thiomalate (25 microgram/ml) for 96 hours. As a result, M phi developed electron dense precipitates within phagolysosomes, as well as marked dilatation of these organelles. Gold incubation also altered a number of M phi functions. While viability and adherence were unaffected, the capacity to spread on surfaces was diminished. Pinocytosis of soluble proteins and phagocytosis of opsonized sheep erythrocytes were impaired, but Fc mediated particle binding was not. These data indicate that gold can alter certain functional activities of M phi and support the idea that the major action of gold in rheumatoid arthritis results from its capacity to alter M phi function.