Steroid-resistant, cyclosporine-responsive, relapsing nephrotic syndrome.

Eighteen children with steroid-resistant nephrotic syndrome received cyclosporine A (CsA), including 7 patients with minimal change disease, 4 with focal segmental glomerulosclerosis and 7 with mesangial hypercellurarity. Doses were adjusted to maintain whole blood trough levels at 80-200 ng/ml and ranged from 5 to 10 mg/kg (mean 7 mg/kg). Fourteen patients responded after 2 months of therapy with either a complete or partial remission, and received a total of 12 months of CsA with low-dose corticosteroids. Remission rates were similar among the three histological types, although complete remissions occurred more commonly in minimal change disease, while the other two histological types tended to have partial responses. Serum creatinine values ranged from 0.3 to 1.2 mg/dl at the start of treatment and were stable in 17 of 18 patients during CsA therapy. CsA was discontinued after 12 months in 11 responders. Relapses were a significant problem. Nine patients had 16 relapses, all occurring within 6 months after discontinuing CsA; 13 of 16 relapses responded to CsA and corticosteroids. Five children had multiple relapses. Three patients who initially responded to treatment had CsA-resistant relapses. There were no differences among the histological types with respect to the occurrence of relapses or response to CsA after relapsing. Four patients developed chronic renal failure, including 2 of 4 who failed initial therapy and 2 of 3 who developed CsA-resistant relapses. In conclusion, initial therapy with CsA was effective in resolving nephrotic syndrome in steroid-resistant patients. However, CsA dependency, frequent relapses and the development of chronic renal failure presented significant problems.