Complement Receptors in Pathological Human Renal Glomeruli

Abstract

Glomerular complement [c] receptors (GCR) were demonstrated by the adsorption of C3 coated sheep erythrocytes to cryostat sections of human kidneys. An epithelial localization of the GCR is implied by the binding pattern of the indicator cells. The GCR activity was reduced in all glomeruli, where in vivo deposition of immunoglobulin [Ig] and C3 along the capillary wall was observed. In 14 out of 19 biopsies where deposits in the mesangium were seen, reduced GCR activity was also observed; GCR activity was normal in the other 5. Immunofluorescence and hemadsorption tests performed on the same section showed that C3 deposits corresponded to areas showing reduced C receptor activity. Areas outside the C3 deposits adsorbed indicator cells coated with various amounts of C3 similarly to the adsorption to glomeruli seen in normal adult and fetal kidneys. Sclerotic glomeruli showed no GCR activity. The C receptors play a role for the binding of C-containing complexes in glomeruli.