The significance of extracapillary proliferation

Renal biopsy and clinical data from 60 patients with crescent formation were correlated. Nephropathy was related to infection (15 cases), malignancy (four) and trichlorethylene exposure (two). Four cases had extrarenal signs. Isolated proteinuria was found 0.5-20 yr before biopsy in 16. Only 17 patients had rapidly progressive glomerulonephritis on clinical criteria. Nineteen patients (35%) are alive with functioning kidneys. Outcome was significantly related to percentage crescentic involvement (p less than 0.02) and oliguria (p less than 0.05) and renal function (p less than 0.01) at presentation. Preceding infection was a favourable sign. Extracapilly glomerulonephritis is not a single entity.