Medical University of South Carolina, Charleston, South Carolina;, †University of Tennessee College of Medicine in Chattanooga, Chattanooga, Tennessee;, ‡George Washington University, Washington, DC;, §Duke University, Durham, North Carolina;, ‖Durham Veterans Affairs Medical Center, Durham, North Carolina, ¶Ralph H. Johnson Veterans Affairs Medical Center, Charleston, South Carolina.
Clin J Am Soc Nephrol. 2013 Dec;8(12):2043-52. doi: 10.2215/CJN.03510413. Epub 2013 Sep 5.
Prognostic biomarkers that predict the severity of AKI at an early time point are needed. Urinary angiotensinogen was recently identified as a prognostic AKI biomarker. The study hypothesis is that urinary renin could also predict AKI severity and that in combination angiotensinogen and renin would be a strong predictor of prognosis at the time of AKI diagnosis.
DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: In this multicenter, retrospective cohort study, urine was obtained from 204 patients who developed AKI after cardiac surgery from August 2008 to June 1, 2012. All patients were classified as having Acute Kidney Injury Network (AKIN) stage 1 disease by serum creatinine criteria at the time of sample collection. Urine output was not used for staging. Urinary angiotensinogen and renin were measured, and the area under the receiver-operating characteristic curve (AUC) was used to test for prediction of progression to AKIN stage 3 or in-hospital 30-day mortality. These biomarkers were added stepwise to a clinical model, and improvement in prognostic predictive performance was evaluated by category free net reclassification improvement (cfNRI) and chi-squared automatic interaction detection (CHAID).
Both the urinary angiotensinogen-to-creatinine ratio (uAnCR; AUC, 0.75; 95% confidence interval [CI], 0.65 to 0.85) and the urinary renin-to-creatinine ratio (uRenCR; AUC, 0.70; 95% CI, 0.57 to 0.83) predicted AKIN stage 3 or death. Addition of uAnCR to a clinical model substantially improved prediction of the outcome (AUC, 0.85; cfNRI, 0.673), augmenting sensitivity and specificity. Further addition of uRenCR increased the sensitivity of the model (cfNRI(events), 0.44). CHAID produced a highly accurate model (AUC, 0.91) and identified the combination of uAnCR >337.89 ng/mg and uRenCR >893.41 pg/mg as the strongest predictors (positive predictive value, 80.4%; negative predictive value, 90.7%; accuracy, 90.2%).
The combination of urinary angiotensinogen and renin predicts progression to very severe disease in patients with early AKI after cardiac surgery.
需要能够在早期预测急性肾损伤（AKI）严重程度的预后生物标志物。尿血管紧张素原最近被确定为一种预测 AKI 的预后生物标志物。本研究假设尿肾素也可以预测 AKI 的严重程度，并且血管紧张素原和肾素的组合在 AKI 诊断时是预后的强有力预测因子。
设计、地点、参与者和测量：在这项多中心回顾性队列研究中，收集了 204 名心脏手术后发生 AKI 的患者的尿液，这些患者的尿液采集时间为 2008 年 8 月至 2012 年 6 月 1 日。所有患者均根据采集样本时的血清肌酐标准被归类为急性肾损伤网络（AKIN）1 期疾病。尿排量未用于分期。测量尿血管紧张素原和肾素，使用接收者操作特征曲线（ROC）下面积（AUC）来测试进展为 AKIN 3 期或院内 30 天死亡率的预测。将这些生物标志物逐步添加到临床模型中，并通过无类别净重新分类改善（cfNRI）和卡方自动交互检测（CHAID）评估对预后预测性能的改善。
尿血管紧张素原与肌酐比值（uAnCR；AUC，0.75；95%置信区间[CI]，0.65 至 0.85）和尿肾素与肌酐比值（uRenCR；AUC，0.70；95%CI，0.57 至 0.83）均预测 AKIN 3 期或死亡。将 uAnCR 添加到临床模型中可显著改善对结局的预测（AUC，0.85；cfNRI，0.673），提高了敏感性和特异性。进一步添加 uRenCR 提高了模型的敏感性（cfNRI（事件），0.44）。CHAID 产生了一个高度准确的模型（AUC，0.91），并确定 uAnCR>337.89ng/mg 和 uRenCR>893.41pg/mg 的组合是最强的预测因子（阳性预测值，80.4%；阴性预测值，90.7%；准确性，90.2%）。
尿血管紧张素原和肾素的组合可预测心脏手术后早期 AKI 患者向严重疾病进展。
