Immunosuppressive therapy of childhood idiopathic nephrotic syndrome

Childhood nephrotic syndrome (NS) is a distressing chronic renal disorder with potentially life threatening complications. Over 80% of cases in children are due to minimal change disease and the majority will respond to corticosteroid therapy. Steroid-sensitive NS is considered a relatively benign condition, since progression to end stage renal failure (ESRF) is extremely rare and > 80% will enter spontaneous long-term remission in later childhood. However, the disease is characterised by a relapsing course, placing the child at risk of acute complications, such as infection, hypovolaemia and thrombosis. Frequent relapses can result in a not inconsequential corticosteroid burden or prescription of cytotoxic immunosuppressive therapy to control the disease. In contrast, steroid-resistant and -refractory NS has an unfavourable outcome with a propensity to progress to ESRF. While these clinical entities have an unpredictable response to cytotoxic immunosuppressive therapy, the favourable long-term renal survival associated with children who enter sustained remission has revived the enthusiasm to treat steroid-resistant NS with more aggressive immunosuppressive regimens.