ROC曲线评价血清胱抑素C对早期肾功能损伤的临床诊断价值

The diagnostic value of serum cystatin C by the receiver operating characteristic curve in early diagnosis of nephropathy

目的应用受试者工作特征曲线(ROC)探究血清胱抑素C(Cys C)在诊断慢性肾脏疾病早期肾功能损伤的临床价值,评估ELISA法检测Cys C的最佳诊断临界值。方法将本院2010年2月至2015年2月收治的168例各型肾脏疾病者分为A、B、C(肾功能正常、轻度损伤、中重度损伤)三组,用ELISA法检测三组患者及50例健康体检者血清Cys C、血肌酐(Scr)与尿素氮(BUN)水平,绘制ROC曲线,比较三者诊断价值并评估最佳诊断临界值。结果(1)B组Cys C检测结果与健康对照组比较,P<0.01,差异有显著性统计学意义,而Scr、BUN差异无统计学意义。(2)Cys C对诊断肾功能轻度损伤的敏感性为96.22%,明显高于传统指标Scr、BUN,Cys C的约登指数高达0.96,阴性似然比最低为0.04。(3)Cys C诊断早期肾功能损伤的最佳诊断点为1.07mg/L(95%CI:0.876±0.021),ROC曲线下面积为0.933,明显优于Scr、BUN。结论 ELISA法检测血清Cys C对诊断慢性肾脏疾病早期肾功能损伤有重要临床价值,是观察肾脏疾病发展变化较为理想的血清学标志物,与肾损伤的炎性发展可能存在分子学机制。

Objective To explore the value of Cys C by the receiver operating characteristic curve in early diagnosis of nephropathy,to evaluate the optimum diagnosis critical value of ELISA. Methods 168 patients with chronic nephro- sis in the hospital were divided into A,B,C three groups （the normal renal function group, the early renal dysfunction group and the middle and late renal dysfunction group）, 50 healthy individuals were selected as the control group. The levels of Cys C, serum creatinine（Scr）,glomerular filtration rate （GFR） by ELISA,compared their diagnostic value by the ROC curve. Results ① Compared with the control group,the level of Cys C in B group had had significantly chan- ges （P〈0.01）, but without Scr and BUN. ② Sensitivity of Cys C for the diagnosis of renal injury is 96. 220%, the Youden index of Cys C is 0.96,and the negative likelihood ratio was 0.04. ③ The optimum diagnosis critical value of ELISA is 1.07mg/L （95%CI：0. 876 ±0. 021）, the area under the ROC curve was 0. 933,greater significantly than Scr, BUN. Conclusion Serum Cys C has a significant clinical value in early diagnosis of nephropathy, the diagnostic rate can he raised. It may has a relationship with the inflammatory development of renal injury.