Mycophenolate mofetil in treatment of childhood steroid-resistant nephrotic syndrome.

INTRODUCTION: The literature on the clinical effectiveness of treatments for steroid-resistant nephrotic syndrome (SRNS) is very limited. The available evidence suggests a beneficial effect of cyclosporine on remission rates. Mycophenolate mofetil (MMF) represents a promising therapeutic alternative without nephrotoxicity. The purpose of the present study was to evaluate the efficacy and tolerance of MMF therapy in children with SRNS. METHODS: Six patients with SRNS were treated with MMF combined with oral prednisolone at a dosage of 1 mg/kg per day. The initial dosage of MMF was 600 mg/m² per 12 hours, adjusted to maintain levels of mycophenolic acid at 2.5-5 µg/mL. The planned duration of study to assess treatment efficacy was 12 weeks. All patients had a pathological renal study. RESULTS: The treatment with MMF was started at a median age of 11 years (range 9-13). Pathological patterns were 4 patients with focal segmental glomerulosclerosis (FSGS), 1 patient with minimal change disease (MCD) and 1 patient with diffuse mesangial proliferation glomerulonephritis (DMP). Only 1 patient, who had MCD, achieved complete remission. One patient went into partial remission. However, the subgroup with no response to MMF appeared to have a reduction in proteinuria and an increase of serum albumin. There were no significant beneficial effects on the level of glomerular filtration. CONCLUSIONS: In this small, single-center study, a therapeutic response to MMF was obtained only in one third of patients. This response rate, though it is low, encourages us to use MMF in some patients who are resistant to conventional therapy for SRNS.