ABSTRACT
Immune complexes are produced whenever there is an antibody response to a soluble antigen. As the immune response progresses, larger immune complexes are formed that trigger the activation of complement, activated components of which bind to the complexes. These are then efficiently cleared by binding to complement receptor 1 (CR1) on erythrocytes, which convey the immune complexes to the liver and spleen. There the complexes are removed from the red cell surface by Kupffer cells and other phagocytes (Fig. 43.1) and ingested via a variety of complement and Fc receptors on the cells lining the sinusoids of the hepatic and splenic circulation. When antigen is released repeatedly so as to sustain the formation of small immune complexes, these complexes tend to be trapped in the small blood vessels of the renal glomerulus and synovial tissue of the joints.
