Subendothelial deposits and tubuloreticular inclusions in lupus nephritis

Electron micrograph in diffuse proliferative lupus nephritis shows massive subendothelial deposits (D) and characteristic tubuloreticular structures (arrow) in the endothelial cells (En). The subendothelial deposits cause marked thickening of the glomerular capillary wall, leading to a wire loop appearance on light microscopy.

Electron micrograph of a normal glomerular capillary loop showing the fenestrated endothelial cell (Endo), the glomerular basement membrane (GBM), and the epithelial cells with its interdigitating foot processes (arrow). The GBM is thin, and no electron-dense deposits are present. Two normal platelets are seen in the capillary lumen.