Low-Dose Cyclosporine Treatment in Chinese Nephrotic Patients With Idiopathic Membranous Nephropathy: An Uncontrolled Study With Prospective Follow-up

Introduction:The optimal dose of cyclosporine A (CsA) in treatment of nephrotic proteinuria in idiopathic membranous nephropathy (IMN) remains inconclusive. We evaluated the efficacy and safety of low-dose CsA combined with low-dose prednisone as induction therapy for Chinese nephrotic patients with IMN. Methods:We conducted a prospective observational cohort study in 18 patients with IMN and nephrotic proteinuria. Twelve patients were refractory to other immunosuppressive therapies. The initial dose of CsA was 1 to 1.5 mg/kg/d combined with 0.15 to 0.50 mg/kg/d prednisone. The dose of CsA was adjusted monthly by 20% to 30% according to efficacy and the 12-hour trough blood concentration (C0) of CsA around 100 ng/mL for 6 months; when proteinuria was <1 g/d, CsA was tapered gradually to a dose of 0.6 to 1 mg/kg/d. Results:Two patients discontinued CsA because of refractory hypertension. The remaining 16 patients had been followed up for 44 ± 15 weeks. Remission was observed in 11 patients (68.8%: complete remission, 6 and partial remission, 5). The effective dose of CsA for remission was 2.1 ± 0.4 (1.5–2.5) mg/kg/d, and the mean C0 of CsA was 92.5 ± 23.5 (58–124) ng/mL. All the 16 patients experienced well-controlled adverse effects, including hypertension (n = 12), hyperuricemia (n = 12), increase of serum creatinine (n = 2), etc. Conclusions:Low-dose CsA combined with low-dose prednisone was effective and safe as induction therapy in majority of Chinese nephrotic patients with IMN, including those refractory to other immunosuppressive regimens.