Rapidly Progressive (Nonstreptococcal) Glomerulonephritis

Eight patients with renal failure associated with a rapidly progressive glomerulonephritis were observed. The onset of illness was insidious and remarkable for the lack of a history suggesting a severe acute glomerulonephritis. The clinical course was brief, lasting from 5 to 27 weeks, and resulted in death from uremia and congestive heart failure. Clinical, bacteriologic, and serologic studies revealed no evidence of previous streptococcal infection, systemic disease, or significant drug ingestion. Histopathologic analysis of renal biopsy specimens revealed marked extracapillary cell proliferation with pronounced crescent formation, moderate to marked glomerulosclerosis, and only minimal or mild hypercellularity of the glomerular tufts. There was a rapid evolution of extensive fibrotic changes in the glomerular epithelial crescents. There was no arteritis or arteriolitis. Material with periodicity of fibrin was seen by electron microscopy and demonstrated by immunofluorescence among cells forming crescents. Subepithelial "humps" considered diagnostic of acute poststreptococcal glomerulonephritis were not seen in any specimens studied by electron microscopy. Although rapidly progressive glomerulonephritis has been described previously, it has never been distinguished clearly from acute poststreptococcal glomerulonephritis. Its pathogenesis is unknown. Nevertheless, our findings suggest that rapidly progressive glomerulonephritis may be a distinct clinical and morphologic primary renal disease of unknown cause, with a malignant clinical course.