Type III membranoproliferative glomerulonephritis: long-term clinical and morphologic evaluation.

Seventeen patients with Type III membranoproliferative glomerulonephritis (MPGN) have been followed for more than two years; 16 were treated with alternate day prednisone. Clinical deterioration correlated with nephrotic syndrome (NS) at diagnosis: 3 of 7 patients with NS at diagnosis developed end-stage disease. Serial biopsies in the others showed progressive disease in one, improvement in one and no change in two. Of 10 patients without NS at diagnosis, 6 have improved clinically, 2 are unchanged and 2 are worse. In serial biopsies, 6 showed improved morphology and 4 were unchanged. The results indicate that Type III MPGN will stabilize or improve in most treated patients. The absence of ultrastructural transition of a Type III glomerular lesion to another type and the presence of distinctive immunofluorescent findings and complement abnormalities confirm that Type III is a unique form of MPGN.