Nephritic Glomerulopathies



While some glomerular lesions regularly pre­sent as the nephrotic syndrome (edema and heavy proteinuria), other patterns of renal histopathol-ogy present predominantly as nephritic syn­dromes (hypertension, hematuria, and protein­uria). The common pattern in nephritic glomerular lesions is that of cellular proliferation (mesangial, endothelial, or epithelial cells) and cellular infiltration (polymorphonuclear leuko­cytes, macrophages). Table 34-2 lists the common histopathological and clinical diseases that pre­sent with major manifestations of the nephritic syndrome. Some of these entities are dicussed in subsequent sections.

The clinical presentation of the nephritic syn­dromes parallels the pattern of glomerular injury. Three general categories of cellular proliferation, each representing one part of the spectrum of clin­ical nephritis, can be described. Focal nephritis, which affects portions of some glomeruli, is most often associated with hematuria and proteinuria but with little or no reduction in GFR. Diffuse pro­liferative nephritis from any etiology, in which nearly all glomeruli show extensive cellular pro­liferation and/or infiltration, is usually associated with azotemia and hypertension in addition to he­maturia and proteinuria. Finally, glomeruloneph­ritis with extensive crescent formation is almost always associated with progressive deterioration of renal function.

A given case of glomerulonephritis may run its course at any one of the above stages, but cross­over from one histological lesion to another is common among most types of glomerulonephri­tis. The finding of extensive crescent formation on a renal biopsy (s50 per cent of glomeruli af­fected) carries an ominous prognosis for reversi­bility of the renal lesion.