Advances in understanding the morphology of glomerular disease.

Before the introduction of renal biopsy our understanding of the morphology of glomerular disease was extremely limited. This could be blamed in part on the problems of interpretation of necropsy material obscured to a greater or lesser extent by post-mortem artefact. The introduction of renal biopsy made fresh renal tissue available and acted as a stimulus for the development of a variety of new histological techniques which have subsequently proved to be of great value. In 1957 Jones published his silver-impregnation method for the demonstration of glomerular basement membrane material1 and illustrated many of the morphological changes which could occur in glomerular disease. I regard his technique as the most valuable single method in the day-today diagnosis of glomerular disease, provided it is used with a haematoxylin and eosin counterstain. Many people virtually waste the technique by usingaweak light green counterstain which is almost useless. In the normal glomerulus, the silver impregnation technique clearly identifies the glomerular capillary wall and mesangial matrix while haematoxylin stains the various nuclei, and eosin stains the proteins. In membranous glomerulonephritis, the Jones technique can be used to illustrate the argyrophilic "spikes" (Fig. I) which classically project from the Fig. 1 Part of a glomerulus showing a complicated pattern of argyrophilic projections from the outer aspect of the capillary basement membranes in membranous glomerulonephritis. Jones' methenamine silver with haematoxylin and eosin counterstain x 560.