Is single-daily low-dose cyclosporine therapy really effective in children with idiopathic frequent-relapsing nephrotic syndrome?

Abstract

A recent study on renal transplant patients has shown that a single dose of cyclosporine (CsA) has added the advantage of decreasing dosages and adverse effects, while maintaining graft function. However, the efficacy of this regimen in children with idiopathic frequent-relapsing nephrotic syndrome (NS) remains controversial. 20 children with steroid-dependent NS or CsA-dependent NS (18 with minimal change disease, MCD and 2 with focal segmental glomerulosclerosis, FSGS) were enrolled in this prospective study. CsA was commenced at 1.5 â 2 mg/kg, given as a single daily dose before breakfast, and the dose was adjusted to reach 2 hours post-dose CsA levels (C2) of 600 - 800 ng/ml. In 9 out of 18 patients with MCD, treatment with single-daily CsA for a median of 13 months (range 7 - 21) resulted in a reduction of mean minimum prednisolone (PSL) dose from 1.1 A+/- 0.55 to 0.04 A+/- 0.09 mg/kg on alternate days (p < 0.01), and the median relapse rate from 1.3 (1.1 - 2.5) to 0 (0 - 0.2) episodes/6 months (p < 0.01). Of them, PSL could be weaned off in 7 patients (4 of 6 with steroid-dependent NS, only 3 of 14 with CsA-dependent NS) without relapse of NS while on this therapy. However, 11 out of 20 were considered to have treatment failure: 1 with steroid-dependent NS and 10 with CsA-dependent NS. In 2 patients having FSGS, this method showed no beneficial effects. In 18 patients with MCD, relapse free ratio on single-daily CsA therapy was significantly higher in patients whose average C2 levels were greater than 700 ng/ml (p < 0.05). Our experience demonstrates that single-daily low-dose CsA therapy maintaining C2 levels greater than 700 ng/ml may be effective in children with steroid-dependent NS or MCD, with no relapse. In contrast, the usefulness of this regimen in children with CsA-dependent NS appears to be limited.