Treatment of idiopathic nephrotic syndrome with cyclosporin A in children.

Twenty-two children (15 boys, 7 girls), aged from 1 to 9 years (mean 4.6 years) at the onset of idiopathic nephrotic syndrome (INS) received cyclosporin A (CsA) because of steroid toxicity or failure to respond to steroids. CsA was given at an initial dose of 5 mg/kg body weight per day, and adjusted to maintain whole blood trough levels at 60 to 180 ng/ml (HPLC). The duration of treatment ranged between 4 and 33 months. In patients who responded to CsA, treatment was continued for 6-33 months (average 12 months). Treatment was stopped it found to be ineffective after four months. All patients had normal kidney function at the onset of CsA therapy. Of the 22 cases 10 were frequent-relapsing, steroid-responsive patients who suffered serious side effects of steroid therapy. Six steroid-responsive patients were dependent on high-dose prednisolone for maintenance of remission. Twelve patients were steroid-resistant (SRT), eight of them with mesangial hypercellularity (MES), three focal segmental glomerulosclerosis (FS-GS), and one minimal change disease (MCD). Seventeen patients (77%) responded favorably to CsA, 13 of them with complete remission, three with partial response (two of whom had MES, and one steroid-resistant FSGS), and one relapsed while on CsA. Only five patients in the whole study group showed no response to CsA, two of them had steroid-resistant FS-GS, both of whom developed renal failure in follow-up, and the other three had MES. In conclusion, therapy with CsA may be helpful in resolving nephrotic syndrome in SRT patients. CsA can be used to maintain remission in frequently relapsing nephrotic children. Patients who respond to CsA may have a lasting remission after the cessation of therapy.