Randomized Prospective Controlled Open-labeled Trial of Cyclosporine with/without Low-dose Oral Corticosteroids in Idiopathic Membranous Nephropathy in Adults with Nephrotic Syndrome

Objective We conducted a prospective, randomized controlled, open-label study to investigate the efficacy of a combination of cyclosporine and low-dose prednisolone in patients with idiopathic membranous nephropathy (IMN). Methods We recruited biopsy-proven IMN patients with nephrotic syndrome who had never been treated with immunosuppressants. The patients were randomized into 2 groups treated after randomization with cyclosporine (3 mg/kg/day) alone or with an oral low-dose corticosteroid (prednisolone 15 mg/day) for 24 months. Results We recruited 30 patients with IMN and nephrotic-range proteinuria, 28 of whom were included in this study. Fourteen patients were randomized for treatment with only cyclosporine (Group A), and 14 were randomized for treatment with cyclosporine plus low-dose corticosteroids (Group B). Cyclosporine monotherapy induced remission in 12 of the 14 patients in Group A, including partial remission in 7 patients (50.0%) and complete remission in 5 patients (36.7%). In Group B, 12 of 14 patients achieved proteinuria remission, including 11 (78.6%) with complete remission and 1 (7.1%) with partial remission. Although there was no marked difference in the overall remission rate, the complete remission rate was significantly higher in Group B than in Group A (p=0.02). Furthermore, there was a statistically significant difference between the groups in the time from the start of the study to complete remission (10.2±7.8 months in Group A; 9.5±6.1 months in Group B, p=0.03). Conclusion The combination of cyclosporine and low-dose corticosteroid treatment is an effective and important option in the management of patients with IMN with nephrotic-range proteinuria, either as an initial therapy or as a long-term treatment.