Is tacrolimus for childhood steroid-dependent nephrotic syndrome better than ciclosporin A?

The dosage and 3 months duration of glucocorticoidtreatment in steroid-sensitive childhood idiopathicnephrotic syndrome, mainly associated with thehistological picture of minimal change glomerulopa-thy, is based on the evidence of randomized clinicaltrials with clear-cut end points [1–3]. Duration of up to7 months of the therapy may even be more effective inachieving sustained remission. A further well-designedand adequately powered randomized controlled trial is,however, required. To avoid steroid toxicity, there isconvincing evidence for the use of oral cyclopho-sphamide in patients with frequent relapses [4]. Theevidence, however, is less stable for the treatment ofsteroid-dependent nephrotic syndrome (SDNS), i.e.recurrence of nephrotic syndrome within 2 weeks ofcessation of steroid treatment [5,6]. One of the majorconcerns with regard to the use of alkylating agentssuch as cyclophosphamide or chlorambucil in childrenand adolescents is gonadotoxicity [7]. Therefore,ciclosporin A (CSA) has been advocated when toxiceffects of prednisone and cyclophosphamide areexpected. CSA results in a remission rate of 85% inchildren with SDNS, bearing, however, the risk ofcalcineurin inhibitor-induced nephrotoxicity [8].Thus, alternative immunosuppressive drugs such asmycophenolate mofetil [9,10], rituximab [11] andsirolimus [12] are currently under investigation.Levamisol has been found to be of benefit in SDNSand has limited toxicity [13]. Data on the use of thecalcineurin inhibitor tacrolimus (TAC) are scarce.