Figure 1.

Glomerular changes consistent with minimal change disease during partial remission. (a) Normal glomerulus. The glomerulus is slightly enlarged, but shows normal cellularity. All of the capillary loops are patent, and the capillary walls are of normal thickness. All 4 glomeruli in this biopsy showed this appearance (periodic acid–Schiff [PAS], original magnification ×300). (b) Normal glomerulus on Jones silver stain. The vascular pole is sectioned so that it appears in the center of the glomerulus, but the glomerulus is of normal size and cellularity. All of the capillary loops are patent, and the capillary walls are of normal thickness (original magnification ×300). (c) Immunofluorescence showed 1+ staining for C1q. This is of uncertain significance, but, in the context of visible immune complex deposits on electron microscopy, raises consideration for C1q nephropathy. (d,e) The ultrastructural appearance was nearly normal by electron microscopy (EM). The glomerular basement membranes demonstrate normal thickness and texture. There is no increase in mesangial matrix. The endothelial fenestrations are normal. Partial foot process effacement is present, and there are microvillus changes in the podocyte cytoplasm. These changes are less diffuse than typically seen in the setting of untreated minimal change nephrotic syndrome.