[Disordered permeability of the glomerular filter for middle- and high-molecular serum proteins in various morphologic types and stages of chronic glomerulonephritis].

Investigation of glomerular filter permeability for serum immunoglobulins and albumins in 83 patients with chronic glomerulonephritis (CGN) with nephrotic proteinuria has shown that in mesangioproliferative glomerulonephritis permeability for IgM is rare, for IgA and IgG moderately raised; in a marked but not maximum degree of permeability for albumins, it is characterized by considerable variability. In maximum permeability for albumins there is a tendency to the reduction of the ratio of IgA and IgM clearances to albumin clearance, and variability of these indices. In membranous CGN the structure of nephron permeability for serum proteins is identical but it remains unchanged with a sharp rise of albumin fractional clearance. In mesangiocapillary CGN permeability for IgM is more frequent and enhanced for IgG. in focal-segmental glomerular hyalinosis/sclerosis and diffuse-fibroplastic GN permeability for IgG is considerably raised unrelated to a degree of permeability for albumins. Sclerotic changes are accompanied by elevated permeability for IgG.