Supplementary Material for: Predictors of Kidney Outcomes of Anti-Glomerular Basement Membrane Disease in a Large Chinese Cohort

<b><i>Introduction:</i></b> Anti-glomerular basement membrane (GBM) disease is a rare but the most aggressive form of glomerulonephritis. To dissect the prognostic factors, we retrospectively analyzed the clinical features of a large cohort and compared the clinical features and prognosis during decades. <b><i>Methods:</i></b> Data on clinical manifestation, treatment, and prognosis were collected. Cox models and receiver operating characteristic (ROC) curve were used to investigate the predictors for outcomes. The Kaplan-Meier curve and log-rank test were used to compare kidney and patient survival. <b><i>Results:</i></b> A total of 448 patients were enrolled. Patient survival and kidney survival at 1 year was 69.4% and 37.7%, respectively. During the past 3 decades, mortality at 3 months and 1 year significantly dropped from 37.5% and 57.1% in 1991–2000 to 2.8% and 6.9% in 2011–2020 (<i>p</i> &lt; 0.001), respectively; kidney prognosis showed a tendency of improvement as well. Serum creatinine (Scr) on diagnosis (HR, 1.16; 95% CI, 1.05–1.29) and crescent percentage (HR, 1.73; 95% CI, 1.34–2.24) were independent predictors for end-stage kidney disease. ROC curve showed that the optimal cutoff point of Scr on diagnosis for prediction of dialysis dependency at 1 year was 536.4 μmol/L (sensitivity 88.3% and specificity 80.8%). Antineutrophil cytoplasmic antibodies (ANCAs) positivity (HR, 4.43; 95% CI, 1.72–11.38) was a predictor for mortality. Plasma exchange was associated with a better patient prognosis (HR, 0.40; 95% CI 0.16–0.95). <b><i>Conclusion:</i></b> Scr on diagnosis and percentage of crescents were predictors for kidney outcomes. Positive ANCA was a predictor for mortality. Overall patient prognosis of anti-GBM disease was improved during the past 3 decades.

<b><i>引言：</i></b> 抗肾小球基底膜（anti-glomerular basement membrane, GBM）病是一种罕见但恶性程度最高、进展最为迅速的肾小球肾炎亚型。为明确其预后影响因素，本研究回顾性分析了大型队列患者的临床特征，并对比了近30年间的临床特征与预后变化。<b><i>方法：</i></b> 收集患者临床表现、治疗方案及预后相关数据。采用Cox比例风险模型与受试者工作特征（receiver operating characteristic, ROC）曲线探究预后结局的预测因子；通过卡普兰-迈耶（Kaplan-Meier）曲线及对数秩（log-rank）检验比较患者生存与肾脏生存情况。<b><i>结果：</i></b> 本研究共纳入448例患者。患者1年生存率与肾脏1年生存率分别为69.4%与37.7%。近30年间，患者3个月及1年死亡率从1991-2000年的37.5%、57.1%显著降至2011-2020年的2.8%、6.9%（p<0.001）；肾脏预后亦呈现改善趋势。确诊时的血清肌酐（serum creatinine, Scr）（风险比HR=1.16，95%置信区间CI：1.05~1.29）与新月体百分比（HR=1.73，95%CI：1.34~2.24）是终末期肾病的独立预测因子。ROC曲线分析显示，用于预测1年透析依赖的确诊时Scr最优截断值为536.4μmol/L（灵敏度88.3%，特异度80.8%）。抗中性粒细胞胞浆抗体（antineutrophil cytoplasmic antibodies, ANCAs）阳性（HR=4.43，95%CI：1.72~11.38）是患者死亡的预测因子。血浆置换与更佳的患者预后相关（HR=0.40，95%CI：0.16~0.95）。<b><i>结论：</i></b> 确诊时的血清肌酐水平与新月体百分比是肾脏预后的影响因素。抗中性粒细胞胞浆抗体阳性是患者死亡的预测因素。近30年来，抗GBM病患者的整体预后得到了显著改善。