Supplementary Material for: Idiopathic Membranous Nephropathy: Clinical and Histologic Prognostic Features and Treatment Patterns over Time at a Tertiary Referral Center

<b><i>Background:</i></b> Idiopathic membranous nephropathy (i-MN) is a leading cause of nephrotic syndrome in adults and results in end-stage renal disease in approximately one third of patients. There are few large, long-term US studies evaluating clinical and histologic prognostic factors in i-MN. <b><i>Methods:</i></b> We describe 132 patients with biopsy-proven i-MN who were followed for a mean period of 68 months at our tertiary referral center from 1977 to 2009, and we analyzed clinical and histologic features that predicted renal outcomes. <b><i>Results:</i></b> The presence of hypertension and treating physician’s decision to institute immunosuppression were negative predictors of attaining complete or partial remission. Among clinical variables, impaired renal function (eGFR &lt;60 ml/min/1.73 m²) at time of presentation was the only variable at presentation associated with an increased risk of reaching end-stage renal disease. The use of statins and RAAS blockers were protective. The choice of corticosteroids as the initial immunosuppressive agent by referring physicians decreased over time but even in the most recent era (2000–2008) was significant (33%). <b><i>Conclusion:</i></b> Renal function at presentation and non-white race were the main predictors of a worse renal outcome. Corticosteroid therapy is still being adopted as first-line therapy in a significant number of patients in this era. The development of guidelines may help clarify the treatment strategies of i-MN.

**<i>背景：</i>** 特发性膜性肾病（Idiopathic membranous nephropathy，简称i-MN）是成人肾病综合征的首要病因，约三分之一的患者会进展为终末期肾病。目前美国针对i-MN的临床与组织学预后因素开展的大型长期研究较为匮乏。**<i>方法：</i>** 本研究纳入1977年至2009年间于本三级转诊中心接受随访的132例经活检证实的i-MN患者，平均随访时长为68个月，并分析了可预测肾脏预后的临床及组织学特征。**<i>结果：</i>** 高血压的存在以及主治医生启动免疫抑制治疗的决策，是患者获得完全或部分缓解的不良预测因素。在临床变量中，就诊时肾功能受损[估算肾小球滤过率（estimated glomerular filtration rate，eGFR）<60 ml/min/1.73 m²]是唯一与进展为终末期肾病风险升高相关的就诊时基线变量。他汀类药物与肾素-血管紧张素-醛固酮系统（renin-angiotensin-aldosterone system，RAAS）阻滞剂的使用具有肾脏保护作用。转诊医生选择糖皮质激素作为初始免疫抑制药物的比例随时间推移逐渐下降，但即便在最近的2000–2008年期间，该比例仍达33%，具有统计学意义。**<i>结论：</i>** 就诊时的肾功能水平与非白人种族是肾脏预后较差的主要预测因素。在当前临床实践中，仍有相当比例的患者将糖皮质激素治疗作为一线治疗方案。制定相关临床指南或有助于明确i-MN的规范化治疗策略。