Management of recurrent nephrotic syndrome after kidney transplantation in children.

Steroid-resistant nephrotic syndrome (NS) with focal glomerulosclerosis and its recurrence after transplantation (Tx) are mainly seen in children. The average recurrence rate is 30% and the graft loss is half this; the risk of recurrent NS in subsequent Tx is 50 to 80% according to the fate of the primary allograft. The immediate appearance of proteinuria after Tx suggests that circulating factor(s) might be present which alter the glomerular permeability. Several therapeutic schedules have been proposed and give conflicting results. However, from the current literature, a 3-step management should reasonably be settled: 1) preventive measures in patients at risk include bilateral nephrectomy prior to Tx and introduction of intravenous cyclosporine A (target CyA whole blood level 200 to 250 ng/ml) as early as possible in association with prednisone and azathioprine (+/-anti-thymocyte globulin), 2) in recurrent patients who were not under such a CyA preventive regime, high dose intravenous CyA should be started as soon as possible (target CyA whole blood level 250-350 ng/ml), 3) in children who fail to respond to the above therapeutic proposals, a combination of plasmapheresis followed by substitutive immunoglobulins in association with methylprednisolone pulses and cyclophosphamide instead of azathioprine for 2 months should be proposed early.