Clearance and organ localization of particles and soluble complexes in mice with circulating complexes

The clearance and organ localization of a number of substances cleared by either Fc-dependent or -independent mechanisms was studied in normal mice and in mice with endogenously produced persistent circulating complexes. Clearance of covalent dimers of mouse IgG, chicken IgG and ovalbumin were no different between the two groups of mice. By contrast, hepatic and splenic uptake of dimeric mouse IgG (but not of chicken IgG or ovalbumin dimer) was impaired in the mice with persisting complexes. Surprisingly the rate of clearance of sheep red blood cells (SRBC) was increased in mice with persisting complexes as was hepatic uptake of polyvinyl pyrrolidone. It is suggested that the mononuclear phagocytes of mice with persistent circulating complexes are non-specifically stimulated while their ability to take up soluble complexes by Fc-dependent attachment is selectively impaired.