Progressive passive Heymann nephritis in the rat.

Progressive passive Heymann nephritis was produced in rats by simultaneous intravenous injections of heterologous antirat glomerular basement membrane antiserum and heterologous antirat kidney tubular fraction 3 antibody. The animals were killed at 16 weeks by which time approximately one-half of them were severely proteinuric. The glomeruli showed beaded immune deposits around the capillaries by immunofluorescence, and on electron microscopy osmiophilic deposits were noted in the subepithelial zones and within the glomerular basement membrane. The lesion resembled that of severe Heymann nephritis. gamma-Globulin eluted from the kidneys contained an autologous IgG that reacted with the brush border region of the renal proximal tubules of normal rats. This component was present in proteinuric and nonproteinuric animals. It is concluded that the progression results from the development of autoantibodies to the tubular nephritogenic antigen and the proteinuria is related to increasing deposition of immune complexes in the glomeruli.