Long-term immunosuppressive therapy of idiopathic membranoproliferative glomerulonephritis.

Fifty cases of idiopathic membranoproliferative glomerulonephritis were followed up for an average of 10 +/- 0.9 (SE) years. Forty of them, who presented a nephrotic syndrome, were treated by immunosuppressive drugs (prednisone, azathioprine, chlorambucil, cyclophosphamide) for 79 +/- 9.7 (SE) months. Cumulative survival ratio for 5, 10 and 15 years after enrollment was 0.90, 0.82 and 0.77 and after appearance of first symptoms or signs of kidney disease as determined by anamnestic data 0.97, 0.91 and 0.90 accordingly. Triple-drug therapy (prednisone and azathioprine combined with chlorambucil or cyclophosphamide) was more effective in improving proteinuria than other immunosuppressive regimens. No serious side effects were encountered.