尿液KIM-1、NGAL和IL-18联合检测在大鼠缺血再灌注急性肾损伤早期诊断中的意义

Implication of combined urinary KIM-1 NGALand IL-18 in early diagnosis ofischemia reperfusion acute kidney injury

目的探讨尿液肾损伤分子-1（KIM-1）、中性粒细胞明胶酶相关脂质运载蛋白（NGAL）和白介素-18（IL-18）联合检测在大鼠缺血再灌注急性肾损伤（AKI）早期诊断中的意义。方法将40只SD大鼠随机分为缺血再灌注AKI模型组（IR组，30只）和假手术对照组（对照组，10只），采用酶联免疫吸附（ELISA）法测定两组术前及术后6、12、24、48h时的尿液KIM-1、NGAL、IL-18浓度和血肌酐（Scr）值。结果IR组术后各时间点的尿液KIM-1、NGAL和IL-18浓度均较对照组升高（均P〈0．05）。IR组大鼠术后6h时尿液KIM-1、NGAL和IL-18浓度均较术前升高（均P〈0.05），而此时Scr水平和术前的差异则无统计学意义（P〉O05）；尿液NGAL水平于术后12h时达峰值，后浓度逐渐下降；尿液KIM、IL-18水平均于术后24h时达峰值，术后48h时仍维持较高浓度。ROC分析结果显示：术后6h时的尿液KIM-1、NGAL和IL-18联合检测诊断AKI的ROC曲线下面积最高（P〈0．01），且显著优于Scr和上述3种标记物的单独检测（均P〈0.05）。结论尿液KIM-1、NGAL和IL-18是AKI发生时较Scr升高更早的生物学指标，且联合应用早期诊断AKI的作用显著优于Scr和各标记物的单独应用。

Objective To determine the urinary kidney injury molecule-1 （KIM-1）,neutrophil gelatinase-associated lipocalin （NGAL） and Interleukin-18 （IL-18 ）in rats of ischemia/reperfusion （IR） acute kidney injury, and to explore the utility of combined detection of the above three biomarkers in early diagnosis of AKI. Methods Female SD rats were divided into 2 groups for I/R injury model and sham- operated. Urine and blood sample were collected at 5 time-points （ preoperative, postoperative 6h,12h, 24h and 48h）. The concentrations of urinary KIM-1, NGAL and IL-18 were measured by ELISA, meanwhile, serum creatinine levels were observed at indicated time-points. Results Urinary levels of KIM-1, NGAL and IL-18 were significant higher at indicated time-points in the IR group after reperfusion, compared with sham-operated group（P〈0.05 ）. In the IR group, 6 hours after reperfusion, there were significant increases in urinary levels of KIM-1,NGAL and IL-18 （P〈0.05）, with no significant changes in serum creatinine levels （P 〉0.05 ）. Urinary NGAL peaked at 12 hours after reperfusion, and then decreased. And both KIM-1 and IL-18 peaked at 24 hours after reperfusion,remained markedly elevated up to 48 hours after reperfusion. By applying area under the receiver operator characteristic curve ,the The three biomarkers （ urinary KIM-1, NGAL and IL-18）combined had the most powerful diagnostic power [AUC 0.98, （ 95% CI.0.91-1.00）,P〈0.0001] for diagnosis of AKI at 6h after reperfusion, superior to that for single detection and serum creatinine . Conclusion Urinary KIM-1, NGAL and IL-18 were elevated much before the rise in serum creatinine. And compared to single detection and serum creatinine, combined detection of these three biomarkers performed best for the early diagnosis of AKI.