Treatment of idiopathic nephrotic syndrome of childhood

Childhood idiopathic nephrotic syndrome is a rare disease with an incidence of 1-2/100,000. The untreated disease is associated with an increased risk for potentially life-threatening events such as infections, thromboemboli, malnutrition, and alterations in lipid metabolism. It is the objective of therapy to induce and maintain a complete remission of proteinuria. At the same time serious adverse effects of the immunosuppressive therapy need to be minimized. In the initial treatment of children with idiopathic nephrotic syndrome, prednisone is the drug of choice yielding a remission rate of up to 90%. Approximately 30% of children become steroid dependent or suffer from frequent relapses after prednisone withdrawal. In these patients oral cyclophosphamide and, in case of failure, cyclosporin A is indicated, proceeded by renal biopsy. In contrast, patients with steroid-resistant nephrotic syndrome carry a high risk of developing end stage renal failure in the further course of disease. Drugs that are used in the attempt to induce remission are cyclosporin A, intravenous cyclophosphamide, and methylprednisolone. Currently, randomized studies are under way comparing the efficiency of these agents.