Background. The majority of cases of nephrotic syndrome in children is corticosensitive, however in some individuals aggressive cytotoxic therapy is necessary. Cyclosporin A and cyclophosphamide are widely used; however their relative effectiveness in maintaining remission of childhood nephrotic syndrome remains controversial. Methods and Results. Effectiveness of long-term cytotoxic therapy (mean follow-up 7.4 years) in 63 children (mean age 6.19 ± 4.30 years) with nephrotic syndrome was retrospectively analyzed; 14 patients suffered from corticosensitive, 33 from corticodependent and 16 from corticoresistant nephrotic syndrome. Corticotherapy alone was used in 15 patients (23.8%), cyclophosphamide was added in 27 (42.9%) and cyclosporin A in 38 cases (60.3%), while 17 patients (27%) were on both immunosuppressive agents. 84% children relapsed within 24 months after cessation of cyclosporin A. In 8 corticoresistant nephrotic syndrome patients (61.5 %) from 13 children treated with cyclosporin A no remission occurred, in 5 children (38.5 %) was remission obtained within 10 weeks, however in 4 of them relapsed disease during cyclosporin A therapy. 19 (70.4%) of 27 patients on cyclophosphamide therapy were in remission, in 8 of them (42.1%) even 2 years after cyclophosphamide therapy. Conclusions. Cyclophosphamide therapy of childhood nephrotic syndrome is more effective in maintaining long-term remission than cyclosporin A treatment.

        Key words: childhood idiopathic nephrotic syndrome, corticoresistant nephrotic syndrome, cyclosporin A, cyclophosphamide