Cell coat of podocytes in patients with nephrotic syndrome

Abstract
Renal biopsies from 23 patients with the nephrotic syndrome and 5 patients with slight or no proteinuria were examined for the presence of cell coat of podocyte by light microscopy and EM. Of those with nephrotic syndrome, 5 had minimal change disease, 9 focal glomercular sclerosis, 6 membranous nephropathy and 3 amyloidosis. Colloidal Fe and phosphotungstic acid stains were used for the demonstration of anionic and neutral polysaccharide components of the cell coat. On light microscopy, the colloidal Fe reaction showed a reduction in intensity of the stain in glomeruli of patients with massive proteinuria, as compared to those with slight or no proteinuria. On EM, only the cell coat lining the surface of the foot processes disappeared parallel to the loss of these structures, while the coat covering the surface facing the urinary space remained unchanged with both stains.