The Fine Structure of The Glomerulus in Membranous Glomerulonephritis (Lipoid Nephrosis) in Adults

Abstract

The changes in membranous glomerulonephritis (lipoid nephrosis) of adults, as seen with the light and electron microscope, are described. Thin sections studied with the light microscope reveal deposition of an acidophilic protein material, varying in density, outside the basement membrane. This change accounts for the apparent thickening of the basement membrane seen in hematoxylin and eosin and periodic acid-Schiff-stained sections. Electron micrographs confirm the changes seen in the light microscope and also illustrate that the deposit occurs between the basement membrane and the covering epithelial cells. The latter are separated from the basement membrane by the deposit of protein. The deposit is probably derived from extravasated plasma proteins. The extravasation occurs because of increased permeability of the basement membrane. The basement membrane shows only minimal changes in mild, but considerable changes in more advanced lesions. The epithelial changes in the glomerulus and tubules seem to occur secondary to the altered permeability of the basement membrane. A short review of the literature is given and previous findings are correlated with our own. This is illustrated diagrammatically. Emphasis is directed to the fact that our observations are based on correlation between light and electron microscopy, a feature not frequently reported by electron microscopists.