case_images: PMC11730055_01
case_images: A: The glomerulus reveals a normal histology with delicate capillary walls and normal cellularity. (PAS; Magnification x 230); B: The electron microscopy shows diffuse effacement of the foot processes of the glomerular epithelial cells or podocytes with microvillous changes of the cell surface (Original magnification on the EM image, x 6,000); C: The immunofluorescence microscopy shows "fine dusting" of IgG deposited over the podocytes and along the glomerular capillary walls (FITC-labelled anti-IgG; Magnification x 345); D: The double stain with rhodamine-labelled anti-nephrin antibodies (red) and FITC-labelled anti-IgG antibodies (green) shows in yellow the sites where the two signals overlap, indicating complexes of nephrin with human IgG (double immunofluorescence microscopy stain as described above; Magnification x 345); E: Cortical tubules reveal diffuse flattening of the proximal convoluted tubule (PCT) epithelial cells, focal necrosis (n), vacuolization of better-preserved tubules (v), and focal loss of the epithelium (arrow) (PAS; Magnification x 230). PCT = proximal convoluted tubule; Pod = podocyte or glomerular visceral epithelial cell; P = platelets; RBC = red blood cell; End = endothelium, focally swollen; n = necrosis, cell debris; v = vacuolization of epithelial cells.
case_images: CNCS-13-001-01.jpg
case_images: PMC11730055_01_CNCS-13-001-01.jpg
case_images: Figure1
case_images: The viable glomeruli revealed a normal morphology by light microscopy (Figure 1A), the electron microscopy showed extensive podocyte injury with diffuse effacement of the foot process interdigitations, extensive loss of filtration slit diaphragms, and focal detachment of foot processes from the basal membrane (Figure 1B). The immunofluorescence microscopy revealed "fine-dusting" of IgG deposits on the cell surface of podocytes (Figure 1C). Furthermore, the co-localization of IgG and nephrin in the dual stain was strongly suggestive of an anti-nephrin antibody-mediated process (Figure 1D). There was also evidence of acute tubular injury with focal tubular necrosis and mild focal acute interstitial nephritis (Figure 1E).