OBJECTIVE Rituximab is an effective treatment for children with steroid dependent or frequently relapsing nephrotic syndrome. The optimum dosing schedule for rituximab has not been established. We hypothesized that a single low dose of 375 mg/m2 would have comparable outcomes to higher doses in reducing the frequency of relapse and time to B cell reconstitution. METHODS We conducted a multicenter retrospective observational cohort study of children with steroid-sensitive frequently relapsing nephrotic syndrome. Data were extracted from clinical records including the dates of diagnosis, treatment, relapses, the use of concomitant immunosuppression, and lymphocyte subset profiling. Patients treated earlier received variable doses of rituximab, although typically two doses of 750 mg/m2. Later, patients received the current regimen of a single dose of 375 mg/m2. The primary outcome was an absence of clinically confirmed relapse 12 months following rituximab administration. Secondary outcomes were median time to relapse, probability of being relapse-free at 6 and 24 months and time to reconstitution of CD19+ B cells. RESULTS Sixty patients received 143 courses of rituximab. Seven different dosing regimen strategies were used, ranging between 375 and 750 mg/m2 per dose, with administration of 1-4 doses. There was no significant difference in event-free survival at 12 months between dosing strategies. The median time to reconstitution of B cells was not significantly different between groups. CONCLUSIONS Use of a single low-dose regimen of rituximab in the management of frequently relapsing nephrotic syndrome does not affect the probability of relapse at 12 months or time to B cell reconstitution compared to a conventional higher dose.

中文翻译：

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低剂量的利妥昔单抗治疗12个月的结局对肾病综合征同样有效。

目的利妥昔单抗对患有类固醇依赖或经常复发的肾病综合征的儿童有效。尚未确定利妥昔单抗的最佳给药时间表。我们假设375 mg / m2的单个低剂量在减少复发频率和B细胞重建时间方面将具有与较高剂量相当的结果。方法我们对类固醇敏感的经常性肾病综合征儿童进行了多中心回顾性观察队列研究。从临床记录中提取数据，包括诊断日期，治疗日期，复发时间，使用伴随的免疫抑制以及淋巴细胞亚群分析。较早接受治疗的患者接受了不同剂量的利妥昔单抗治疗，尽管通常两次剂量为750 mg / m2。后来，患者接受了目前单剂量375 mg / m2的治疗方案。主要结果是利妥昔单抗给药后12个月没有临床确诊的复发。次要结果为中位复发时间，6和24个月无复发的可能性以及CD19 + B细胞的重建时间。结果60例患者接受了143个疗程的利妥昔单抗治疗。使用了七种不同的给药方案策略，每剂剂量范围为375至750 mg / m2，给药1-4剂。两种给药策略的12个月无事件生存率无显着差异。两组之间重建B细胞的中位时间无显着差异。