Light microscopical examination of glomerular basement membrane in systemic lupus erythematosus.

To obtain as much information as possible from light-microscopy about changes in the glomerular basement-membrane, a thin section microtome attachment is necessary in order to produce 1 to 3 micron sections. The most informative staining method of paraffin embedded tissue is the Muller-Mowry-Masson trichrome (M-M-M) combination stain. The deposits, e.g., in systemic lupus erythematosus (SLE), stain red, the basement membrane light orange and the endothelial cell cytoplasm light pink. With this stain, as with the Muller-Mowry stain, normal glomeruli show an uninterrupted line of blue acid mucopolysaccharides along the basement membrane, where it is joined by foot processes of the epithelial cells. In contrast, in glomeruli from patients with SLE, focal loss of acid mucopolysaccharides is noted.