Department of Cardiology, Anzhen Hospital, Capital Medical University, Beijing 100029, China.
Chin Med J (Engl). 2012 Mar;125(6):1051-6.
Contrast induced acute kidney injury (CIAKI) is an important complication in the use of iodinated contrast media (CM). Our study was to evaluate the neutrophil gelatinase-associated lipocalin (NGAL) and cystatin C for early diagnosis of CIAKI.
The patients with established or suspected coronary artery disease (CAD) with the estimated glomerular filtration rate (eGFR) was more than 30 ml × min(-1) × 1.73 m(-2) and nor more than 90 ml × min(-1)× 1.73 m(-2) were continuously enrolled. The blood samples of the first 50 patients were obtained before and at 2, 4, 8, 24 and 48 hours after procedure to identify the time points at which the biomarkers reached peaks and at which the blood samples of the rest of patients were obtained. The plasma NGAL and cystatin C measure used enzyme-linked immunosorbent assay (ELISA) kit. The diagnostic characteristics of absolute and relative increasing NGAL and cystatin C for CIAKI were evaluated.
Total 311 patients were enrolled, among whom 39 (12.5%) developed CIAKI. Plasma NGAL increased at 2 hours and reached peak at 4 hours after procedure, while plasma cystatin C increased at 2 hours and reached peak at 24 hours after procedure. Thus, we determine rational point of time at 4 hours for NGAL and at 24 hours after procedure for cystatin C, respectively. The plasma NGAL at 4 hours after CM exposure showed largest area under curve (AUC) of 0.662 (95% confidence interval (CI): 0.565 - 0.758, P = 0.002) with 51.5% sensitivity and 80.6% of specificity. The relative increasing 25% of NGAL showed the best sensitivity and specificity of 0.872 and 0.808, respectively, with maximum Youden index of 0.680, while cystatin C with relative increasing more than 25% had 76.9% of sensitivity and 81.2% of specificity. Combined two biomarkers might get more than 90% of specificity.
Single measurement of NGAL or cystatin C had poor sensitivity and specificity; however, the relative increasing 25% of NGAL at 4 hours after CM exposure demonstrated higher diagnostic values for CIAKI. Combining relative increasing plasma NGAL with relative increasing plasma cystatin C might perform better for early diagnosis of CIAKI.
对比剂诱导的急性肾损伤（CIAKI）是使用碘造影剂（CM）的一个重要并发症。我们的研究旨在评估中性粒细胞明胶酶相关脂质运载蛋白（NGAL）和胱抑素 C 对 CIAKI 的早期诊断。
连续纳入肾小球滤过率（eGFR）估计值大于 30ml×min(-1)×1.73m(-2)且不大于 90ml×min(-1)×1.73m(-2)的已确诊或疑似冠心病（CAD）患者。前 50 例患者于操作前及操作后 2、4、8、24 和 48 小时采集血样，以确定生物标志物达到峰值的时间点和其余患者的血样采集时间点。采用酶联免疫吸附试验（ELISA）试剂盒测定血浆 NGAL 和胱抑素 C 水平。评估绝对和相对增加的 NGAL 和胱抑素 C 对 CIAKI 的诊断特征。
共纳入 311 例患者，其中 39 例（12.5%）发生 CIAKI。血浆 NGAL 在术后 2 小时升高，4 小时达峰值，而胱抑素 C 在术后 2 小时升高，24 小时达峰值。因此，我们分别确定 NGAL 的合理时间点为术后 4 小时，胱抑素 C 的合理时间点为术后 24 小时。CM 暴露后 4 小时的血浆 NGAL 曲线下面积（AUC）最大，为 0.662（95%置信区间：0.565-0.758，P=0.002），灵敏度为 51.5%，特异性为 80.6%。相对增加 25%的 NGAL 具有最佳的灵敏度和特异性，分别为 0.872 和 0.808，最大 Youden 指数为 0.680，而相对增加超过 25%的胱抑素 C 的灵敏度和特异性分别为 76.9%和 81.2%。联合两种生物标志物可获得超过 90%的特异性。
单次测量 NGAL 或胱抑素 C 的敏感性和特异性均较差；然而，CM 暴露后 4 小时相对增加 25%的 NGAL 具有更高的 CIAKI 诊断价值。联合相对增加的血浆 NGAL 与相对增加的血浆胱抑素 C 可能更有助于 CIAKI 的早期诊断。
