Light micrograph showing proliferative lupus nephritis

Light micrograph showing a proliferative pattern in lupus nephritis, characterized by areas of cellular proliferation (arrows) and by thickening of the glomerular capillary wall (due to immune deposits) that may be prominent enough to form a "wire loop" (arrowheads). Although proliferative changes can be focal (affecting less than 50% of glomeruli), disease of this severity is usually diffuse.

Light micrograph of a normal glomerulus. There are only one or two cells per capillary tuft, the capillary lumens are open, the thickness of the glomerular capillary wall (long arrow) is similar to that of the tubular basement membranes (short arrow), and the mesangial cells and mesangial matrix are located in the central or stalk regions of the tuft (arrows).