The management of idiopathic nephrotic syndrome in children

Childhood nephrotic syndrome is a rare condition with an incidence of 1-2 per 100000 children aged below 16 years. Untreated idiopathic nephrotic syndrome (INS) is associated with increased risks of life-threatening infection, thromboembolism, lipid abnormalities, and malnutrition. The aim of the management of INS in children is to induce and maintain complete remission with resolution of proteinuria and edema without serious adverse effects of therapy. The majority of children have corticosteroid sensitive idiopathic nephrotic syndrome (CSINS), and in these children, corticosteroid therapy is the mainstay of therapy to induce remission. Data from a meta-analysis of randomized controlled trials (RCTs) indicate that prolonged courses of corticosteroids (up to 7 months) given in the first episode of CSINS reduce the risk of relapse. Nevertheless, many children relapse, and are at risk of corticosteroid toxicity if frequent courses of corticosteroids are required. Data from RCTs supports the use of alkylating agents (cyclophosphamide, chlorambucil), cyclosporine, and levamisole in these children to achieve prolonged periods of remission. The specific management of corticosteroid-resistant idiopathic nephrotic syndrome (CRINS) is more difficult since few therapies are consistently effective, and data from RCTs are limited. In such children, cyclosporine, alkylating agents, and high dose intravenous methylprednisone may be used. In addition to specific therapies for INS, supportive therapies are commonly used to control edema (loop diuretics, aldosterone antagonists, albumin infusions, angiotensin-converting enzyme inhibitors), reduce the risk of infection (antibacterials, pneumococcal vaccination) and thromboembolism (aspirin [acetylsalicylic acid]), and to control hyperlipidemia (HMG-CoA reductase inhibitors), especially in children with CRINS.