Neutrophil and rheumatoid factor-Immunoglobulin G insoluble complex interactions: phagocytosis and sequelae

Studies utilizing 51CrCl3 labelled human immunoglobulin G have demonstrated a quantitative, time-related increase in the uptake of insoluble rheumatoid factor-immunoglobulin G complexes by human neutrophils. A burst of hexose monophosphate shunt activity occurs when these complexes are phagocytized by neutrophils as evidenced by the increased oxidation of glucose-l-14C to 14CO2. Metabolic and electron micrographic studies suggest that a heat stable serum factor is needed for maximum complex uptake and shunt activity. Phagocytosis of complexes did not affect the adherence of neutrophils to nylon fiber columns, but did not produce selective release of lysosomal enzymes. This study has delineated in an in vitro system, functional and metabolic sequelae of neutrophil phagocytosis of insoluble rheumatoid factor-immunoglobulin G complexes, which may be important components of the inflammation occurring in the joints of patients with rheumatoid arthritis.