No abstract

We conducted a multicenter prospective trial to evaluate the efficacy, safety and pharmacokinetics of a single dose of rituximab (375 mg/m(2) body surface area) for the treatment of children with refractory steroid-dependent nephrotic syndrome (SDNS). All patients (n = 12) were able to discontinue steroids at a median of 74 days after treatment. The frequency of relapses per 6 months was significantly reduced and the steroid-free period per 6 months was significantly increased after treatment compared with those before treatment. The condition in nine of the patients (75%) relapsed at a median of 129 days after treatment, and seven patients were given additional rituximab due to steroid dependency. Most of the relapses developed simultaneously with recovery of B-cells. However, three patients (25%) did not have a relapse with B-cell recovery and the disease was kept in remission for more than 1 year. None of the patients developed life-threatening adverse events. This is the first report of a prospective study of a single dose of rituximab for refractory SDNS. Treatment with a single dose of rituximab may be effective for refractory SDNS, but its efficacy to prevent relapses was transient in most of the patients.

The Oxford classification appears to be valid for predicting renal outcome in children.

In this multicenter, open-label, randomized controlled trial, we determined whether 2-month prednisolone therapy for steroid-sensitive nephrotic syndrome was inferior or not to 6-month therapy despite significantly less steroid exposure. The primary end point was time from start of initial treatment to start of frequently relapsing nephrotic syndrome. The pre-specified non-inferiority margin was a hazard ratio of 1.3 with one-sided significance of 5%. We randomly assigned 255 children with an initial episode of steroid-sensitive nephrotic syndrome to either 2 - or 6-month treatment of which 246 were eligible for final analysis. The total prednisolone exposure counted both initial and relapse prednisolone treatment administered over 24 months. Median follow-up in months was 36.7 in the 2-month and 38.2 in the 6-month treatment group. Time to frequent relaps was similar in both groups; however, the median was reached only in the 6-month group (799 days). The hazard ratio was 0.86 (90% confidence interval, 0.64–1.16) and met the non-inferior margin. Time to first relapse was also similar in both groups: median day 242 (2-month) and 243 (6-month). Frequency and severity of adverse events were similar in both groups. Most adverse events were transient and occurred during initial or relapse therapy. Thus, 2 months of initial prednisolone therapy for steroid-sensitive nephrotic syndrome, despite less prednisolone exposure, is not inferior to 6 months of initial therapy in terms of time to onset of frequently relapsing nephrotic syndrome.

We present the cases of two children with steroid-resistant nephrotic syndrome (SRNS) who were treated with rituximab (anti-CD20 monoclonal antibody). Both were resistant to conventional therapy, and renal biopsy showed focal segmental glomerulosclerosis (FSGS). Combination therapy with methylprednisolone pulse therapy and plasmapheresis was the only way to decrease proteinuria. However, the patients suffered severe reactions to steroid treatment. We therefore treated them with rituximab in a single dose of 375 mg/m(2), which resulted in the rapid clearing of circulating CD19-positive B cells. One month after rituximab treatment, both achieved partial remission; one patient has maintained complete remission for 8 months, and the other relapsed 8 months after the first rituximab treatment with the recovery of peripheral B-cell counts and received a second rituximab treatment. She achieved complete remission 5 months after the second course and has maintained the remission for 2 months. We conclude that rituximab may be an effective treatment for refractory SRNS with FSGS.