[Clinical pathology of the glomerulus--from phenomenon to entity. The extracapillary lesion].
Glomerular crescents are accumulations of proliferating cells in Bowman's capsule and develop as a consequence of glomerular capillary wall ruptures. The severity of crescentic lesion (% glomeruli affected) and crescent size (segmental vs global) are correlated: the higher the percentage of crescentic glomeruli, the more of them are global ones. Several age stages can be differentiated: cellular, fibrocellular, and fibrous crescents. Cellular crescents are mainly composed of epithelial cells derived from the visceral and parietal epithelium, while macrophages and granulocytes are intermingled in widely varying numbers. Crescents can appear in most forms of glomerulonephritis (gn). High percentages of crescents (more than 50%) may be associated 1. with glomerulonephritides of other definition (especially postinfectious gn, mesangial-proliferative gn, IgA-nephritis, membranoproliferative gn, LE-nephritis, Schönlein-Henoch nephritis, cryoglobulinemia) and 2. are the substantial alteration in intra-extracapillary proliferative gn (IEKPGN). Among the latter three forms can be distinguished. a) Anti-glomerular-basement membrane-nephritis and Goodpasture syndrome, respectively (28% of cases), M. Wegener and other vasculitides (8%), and c) idiopathic IEKPGN (63%). Immunohistologic results (IgG, A, M; complement C3, C4) in idiopathic IEKPGN are positive in 53% of cases, but when only cases with initial crescents are evaluated merely 10% are positive, thus secondary trapping of components of humoral immune reaction may be involved. The appearance of crescents generally has a negative influence on prognosis. In cases with more than 80% crescents terminal renal failure occurs in most cases. 50-80% crescents mostly result in compensated renal insufficiency, but less than 50% crescents may be present without elevation of serum creatinine concentration.
Rumpelt
H J
HJ
D002196:Capillaries; D005921:Glomerulonephritis / Q000473:pathology / Q000503:physiopathology*; D006801:Humans; D007678:Kidney Glomerulus / Q000098:blood supply / Q000473:pathology / Q000503:physiopathology*
Klinische Pathologie des Glomerulus--vom Phänomen zur Entität. Die extrakapilläre Läsion.