Necrotizing
glomerulonephritis (NGN) represents small-vessel
vasculitis in the kidney. To assess the diseases associated with necrotizing glomerular changes and their prognosis we studied all 32 patients who had this histologic finding on kidney biopsy from 1969 to 1982 and compared them to those patients who had crescentic, diffuse, or focal and segmental
glomerulonephritis without
necrosis (n = 29). The diseases associated with NGN were
systemic lupus erythematosus (n = 6/15), Henoch-Schönlein
purpura (n = 3/4)
Goodpasture's syndrome (n = 4/7),
Wegener's granulomatosis (n = 6/6), polyarteritis (n = 4/5),
infective endocarditis (n = 2/3), and idiopathic rapidly progressive
glomerulonephritis (n = 7/21). Necrotizing
glomerulonephritis occurred significantly more often in the
vasculitides than in all the other disorders put together. The most difficult diagnosis problem occurred in patients with renal disease and pulmonary
hemorrhage (n = 9), in three of whom diagnosis was uncertain even after autopsy (two autopsies done within one month and one within three months of presentation). A fourth patient had a linear staining for
IgG along the glomerular basement membrane (GBM) on kidney biopsy but was subsequently diagnosed as having
Wegener's granulomatosis. Comparison of patients with without NGN revealed no difference in outcome (death or dialysis) one year after biopsy (38% v 43%) or in serum
creatinine levels one year later (4.6 v 4.8 mg/dL). The prognostic effect of NGN was not obscured by unequal distribution of other adverse prognostic factors in the two groups. The most important prognostic characteristics we identified for outcome were serum
creatinine at biopsy (chi 2 = 24.0, P less than .0004) and the sum of activity and chronicity indexes on biopsy (chi 2 = 12.7, P = .0004). These variables were similarly distributed in patients with and without
necrosis, mean serum
creatinine levels at biopsy being 4.3 v 4.2 mg/dL and sum of indexes 7.8 v 8.0. Other factors such as clinical diagnosis and
therapy were not important prognostically and therefore could not explain our results. We conclude that NGN in patients with active proliferative
glomerulonephritis has multiple causes. Diagnostic difficulties occurred in those with
anti-GBM-negative pulmonary
hemorrhage. The appearances of small-vessel
vasculitis in the kidney did not appear to have prognostic significance.