Supplementary Material for: Therapeutic Approach for Recurrent Focal Segmental Glomerulosclerosis in Pediatric Renal Transplant Recipients: A Single-Center Experience

<b><i>Introduction:</i></b> Recurrence of focal segmental glomerulosclerosis (FSGS) after kidney transplantation (KTx) develops in 40% of patients, leading to graft loss in half of cases. Extracorporeal apheretic treatments, combined with immunosuppressive drugs, seem to be the most promising therapies, but at now limited reports are available, mainly in pediatric patients. <b><i>Objective:</i></b> We aimed to assess the efficacy of immunoadsorption (IA) to treat recurrent FSGS in pediatric patients. <b><i>Methods:</i></b> We report a case series of 4 pediatric patients (aged 4–12 years) followed at our institution for early recurrent FSGS after KTx. FSGS recurrence was treated with early and intensive apheretic treatments IA. <b><i>Results:</i></b> After IA initiation, a partial remission (PR) of proteinuria at 24-month follow-up was achieved only in 1 patient. The others showed a mild reduction of nephrotic proteinuria, without PR, but gained a significant improvement in clinical signs of nephrotic syndrome (reduction of edema, increased serum albumin, and total protein levels). After a median follow-up of 38 (22–48) months, renal function was almost stable over time in all patients, except one who returned to hemodialysis after 22 months. No severe IA-related complications occurred. <b><i>Conclusions:</i></b> According to our clinical experience, IA revealed as a safe and effective therapy to treat patients with recurrent FSGS after KTx and it could maintain stable renal function in 75% of patients.

<b><i>引言：</i></b> 肾移植（kidney transplantation, KTx）后局灶节段性肾小球硬化症（focal segmental glomerulosclerosis, FSGS）的复发率达40%，其中半数病例会导致移植肾失功。体外血液净化分离治疗联合免疫抑制药物看似是最具前景的治疗方案，但目前相关报道有限，且多聚焦于儿科患者。<b><i>研究目的：</i></b> 本研究旨在评估免疫吸附（immunoadsorption, IA）治疗儿科患者肾移植后复发性局灶节段性肾小球硬化症的临床疗效。<b><i>研究方法：</i></b> 本研究纳入本中心随访的4例肾移植后早期复发性局灶节段性肾小球硬化症的儿科患者（年龄4~12岁），针对其局灶节段性肾小球硬化症复发情况，采用早期强化免疫吸附治疗进行干预。<b><i>研究结果：</i></b> 免疫吸附治疗启动后，仅1例患者在24个月随访时实现蛋白尿部分缓解（partial remission, PR）。其余患者的肾病性蛋白尿仅出现轻度降低，未达到部分缓解标准，但肾病综合征的临床症状得到显著改善：水肿减轻、血清白蛋白及总蛋白水平升高。中位随访时长为38（22~48）个月，所有患者的肾功能均基本保持稳定，仅1例患者在随访22个月后需恢复血液透析治疗。未发生与免疫吸附治疗相关的严重不良事件。<b><i>结论：</i></b> 结合本次临床经验，免疫吸附治疗用于肾移植后复发性局灶节段性肾小球硬化症患者安全有效，可使75%的患者维持肾功能稳定。