Acute renal failure in membranous glomerulonephropathy: a result of superimposed crescentic glomerulonephritis.

A patient who presented with acute renal failure and anasarca secondary to crescentic glomerulonephritis superimposed on existing membranous glomerulonephropathy of 15 years' duration is described. The patient responded to an initial course of prednisone but failed to respond to a second course after relapse. The differential diagnosis of acute renal failure in the setting of nephrotic syndrome is discussed. Eighteen cases of crescentic glomerulonephritis superimposed on membranous glomerulonephropathy are reviewed. The clinical setting is heterogeneous with variable presentation and outcome. It appears that patients without antiglomerular basement membrane antibodies have a better prognosis than those who have antibodies. Patients with membranous glomerulonephropathy who develop unexplained acute renal failure should undergo early renal biopsy in order to rule out unexpected pathologic complications.