MRL-lpr/lpr mice show an impairment of IgG aggregate removal which relates to parameters of disease activity

MRL-lpr/lpr mice show an age-related impairment in the removal of heat-aggregated IgG (HAGG) from the circulation. The female mice, which have an earlier mortality than their male counterparts, clear HAGG more slowly than the male animals. Delay in clearance of this probe of mononuclear phagocytic system (MPS) function relates directly to high levels of circulating immune complexes (CIC) and to significant renal damage. In addition it relates indirectly to hepatic and splenic uptake of HAGG. MPS saturation plays a significant role in the pathogenesis of the disease seen in MRL-lpr/lpr mice.