Treatment of tacrolimus or cyclosporine A in children with idiopathic nephrotic syndrome.

Background: Cyclosporine A (CsA) and tacrolimus (TAC) are often alternative treatment choices for patients with nephrotic syndrome.
Methods: In this prospective study, the efficacy and safety of CsA and TAC in inducing and maintaining remission in 74 children with idiopathic nephrotic syndrome (INS) were evaluated.
Results: In terms of short-term efficacy, TAC was more effective than CsA in children with steroid-resistant nephrotic syndrome (χ(2) = 13.75, P = 0.001), although no significant difference in number of episodes of relapse were found in patients with complete remission between the two treatment groups (first year: χ(2) = 0.261, P = 0.88; second year: χ(2) = 2.685, P = 0.26). In patients with frequently relapsing or steroid-dependent nephrotic syndrome, no significant difference in short-term remission (χ(2) = 1.908, P = 0.39) or in relapse frequency during follow-up (within first year: χ(2) = 1.046, P = 0.59; within second year: χ(2) = 0.587, P = 0.75) were found between the two groups. There was a difference in the rate of adverse effects between the two treatment groups [nephrotoxicity: 4/24 (CsA) vs .0/50 (TAC), P = 0.002; hirsutism: 8/24 (CsA) vs. 0/50 (TAC), P < 0.001].
Conclusions: In our pediatric patient cohort, the treatment of steroid-resistant nephrotic syndrome with tacrolimus was associated with higher efficacy and lower renal toxicity in comparison to CsA, although no favorable outcome in relapse rate during long-term follow-up was seen. On the other hand, tacrolimus was not always the better choice to replace CsA in the treatment of severe frequently relapsing or steroid-dependent nephrotic syndrome.