Figure 1.

Anti–brush border antibody disease and lupus nephritis. (a) Glomerular mesangial and endocapillary (arrow) hypercellularity (periodic acid–Schiff stain; original magnification ×400; bar = 20 μm). (b) Glomerular staining for IgG (original magnification ×400; bar = 20 μm). (c) IgG staining along the tubular epithelial apical brush border (original magnification ×400; bar = 20 μm). Inset: granular IgG staining along the tubular basement membrane (original magnification ×600; bar = 20 μm). (d) LRP2/megalin immunofluorescence with normal staining along the apical brush border and ectopic staining along the tubular basement membrane (arrow; original magnification ×600; bar = 20 μm).