Glomerular Basement Membrane Antigens

Abstract

In experimental nephritis produced by the administration of nephrotoxic serum, there is in vivo localization of heterologous immunoglobulin antibodies in a smooth linear pattern along the glomerular basement membrane (GBM) (Hammer and Dixon, 1963). Nephrotoxic serum, produced by immunization with isolated GBM, reacts in vitro by fixing not only to GBM, but also to tubular basement membrane and to Bowman’s capsule as noted by indirect immunofluorescence. The smooth linear staining of these basement membranes is similar to the GBM staining pattern described above in nephrotoxic serum nephritis. The antigenic specificity of nephrotoxic serum has not been defined but it is believed to be due to a reaction with noncollagenous glycoprotein components of GBM, since multiple precipitin lines are formed in Ouchterlony immunodiffusion against collagenase digests of normal GBM (Marquardt et al., 1973). Another experimental model of glomerulonephritis mediated by anti-GBM antibody can be induced in sheep by immunization with heterologous GBM. The proliferative glomerulonephritis, which was first described by Steblay (1962), is associated with linear deposition of host immunoglobulin along the GBM. In this model of experimental anti-GBM nephritis, circulating antibodies to GBM have been detected after nephrectomy (Lerner et al., 1967).