Treatment and long-term follow-up of patients with stage II to III idiopathic membranous nephropathy.

Many important aspects of the therapeutic approach to patients with idiopathic membranous nephropathy are still controversial. There are several reports that the effectiveness of therapy depends on histological staging and severity of interstitial mononuclear cell infiltration. We used several different treatments in 39 patients with stage II to III primary membranous nephropathy with proteinuria more than 2.5 g/d, without hypertension and chronic renal failure at biopsy. Ten patients were not treated, 13 were treated with only steroids, 13 with alternate use of steroids and chlorambucil, and three with cyclosporine A. The follow-up period was 5 to 10 years. Statistics included Kruskall-Wallis and one-way ANOVA analysis. A significant decrease in proteinuria was noted in patients treated with steroids (P < 0.01), from 8.45 +/- 1.04 g/d (mean +/- SEM) to 1. 42 +/- 0.45 g/d after follow-up of 5 years and in patients treated with steroids and chlorambucil (12.9 +/- 2.4 g/d [mean +/- SEM] to 2. 46 +/- 1.38 g/d). Compared with patients treated with steroids (15. 3%) and patients treated with steroids and chlorambucil (15.3%), untreated patients had a high frequency of chronic renal failure after 5 years of follow-up (70%) and had a significant increase in mean serum creatinine (P = 0.008). We conclude that steroid therapy alone, or associated with chlorambucil, is effective in patients with stage II to III membranous nephropathy. Patients responded with a decrease of proteinuria and stable renal function during the long-term follow-up period. The group of patients treated with cyclosporine A was too small to analyze.