| Abstract: | Mice undergoing prolonged (5 to 8 weeks) immunization with cadium-free feeritin were studied 1 to 32 days following the last ferritin injection. Urine protein was measured and renal tissue examined by light, immunofluorescence, and electron microscopy. Immunized animals developed significant proteinuria and circulating antibody to ferritin.by light microscopy, proetinuric animals had a proliferative glomerular lesion with mesangial hypercellularity and martrix increase, focal and segmental necrosis, fibrin deposits, and occasional crescents. Iron stains revealed prominent mesangial iron deposition. In immunized animals, IgG and C3 deposits were localized mainly in the mesanglium. Electron microscopic studies revealed marked deposition of ferratin complexesexpanded mesangial matrix and mesangial interposition. Ferratin immune complexes were also visualized in epithelial spaces. In the latter location ferritin immune complexes occasionally formed characteristic electron-dense subepithelial deposits. In this model, mesangial and subepithelial localization of autologous ferritin immune complexes is associated with development of glomerulonephritis and characteristic mesangial lesions resembling those seen in some types of human glomerulonephritis. |
