Treating the idiopathic nephrotic syndrome: are steroids the answer?

The use of steroids in idiopathic nephrotic syndrome is the major discovery of the twentieth century in the field of pediatric nephrology. At onset of the twenty-first century, steroids remain the first line of treatment at first flare. All the protocols to treat the first flare are similar by a common sequence including a first phase of daily prednisolone/prednisone at a dose of 60 mg/m2/day for at least 4 weeks followed by an alternate-day regimen for several weeks. It appears that a cumulated dose of 2240 mg/m2 given in 8 weeks at the first flare without tapering sequence is not inferior to increased dose and duration in terms of prevalence of frequent relapsers and the subsequent cumulated dose of steroids at 24 months of follow-up. A higher cumulated dose might only be interesting in patients aged below 4 years although a formal demonstration is still missing. Several retrospective studies are concordant to suggest that intravenous methylprednisolone pulses are useful to reach a full urinary remission in case of oral resistance to 4 weeks of oral prednisone/prednisolone. A majority of patients have multiple relapses after the treatment of the first flare and half meet the definition of steroid dependency. In those patients, long-lasting alternate-day prednisone/prednisolone therapy does not lead to long-lasting remission, opening the question of the best strategy of immunosuppression.