Evaluation of chlorambucil therapy in steroid-dependent and cyclophosphamide-resistant children with nephrosis

A prospective study was performed to evaluate the efficacy of chlorambucil in inducing long-term remission in children with steroid-dependent or cyclophosphamide-resistant primary nephrotic syndrome (NS). The 16 steroid-dependent children had a relapse rate of 5.3/patient per year (range 4-8) and a mean age of 8.4 years (range 2-13). The chlorambucil dosage was 0.2 mg/kg per day for a total of 8 weeks. Nine patients (56%) remained in complete remission for an average of 39.2 months (range 16-70). The interval to the first relapse in the remaining 7 ranged from 4 to 41 months and the relapse rate decreased significantly to 0.6 relapses/patient per year (P less than 0.05). Five children had steroid- and cyclophosphamide-resistant NS, 4 with focal segmental glomerulosclerosis and 1 with mesangiol proliferative glomerulonephritis. Chlorambucil was given in a dose of 0.2 mg/kg per day for 8-16 weeks. Complete remission was obtained in 4 patients; 2 patients relapsed. No serious long-term complications were observed in our patients.