Performance evaluation of a particle-enhanced turbidimetric cystatin C assay on the Abbott ci8200 analyzer

Objectives

Glomerular filtration rate (GFR) is widely accepted as the best overall measure of kidney function. Cystatin C is a novel endogenous GFR marker that has been shown to be superior to creatinine for estimation of GFR in several studies. There is a need for cystatin C assays adapted to routine chemistry instrument to minimize turnaround times and allowing 24 h/day availability.

Materials and methods

We have evaluated a new cystatin C assay developed for Architect cSystem (Abbott Laboratories, Abbott Park, IL, USA).

Results

The cystatin C assay showed good agreement with the corresponding assay from Dade Behring (Deerfield, IL, USA). The assay has a very low total imprecision and a good linearity.

Conclusions

The new cystatin C assay is an interesting alternative to current cystatin C assays. On an Architect cSystem the assay can be performed with the same turnaround times and availability as creatinine.     

Comparing different estimated glomerular filtration rate equations in assessing glomerular function in children based on creatinine and cystatin C

Background

Glomerular filtration rate (GFR) is the best marker used to assess renal function. Estimated GFR (eGFR) equations have been developed, and the ideal formula is still under discussion. We wanted to find the most practical and reliable GFR in eGFR formulas. We compared serum creatinine (Scr)‐ and cystatin C (cysC)‐based eGFR formulas in the literature. We also aimed to determine the suitability and the reliability of cysC for practical use in determining GFR in children.

Methods

We have enrolled 238 children in the study. Measurement of 24‐hour creatinine clearance was compared with eGFR equations which are based on Scr, cysC, and creatinine plus cysC.

Results

Of the patients (n = 238), 117 were males (49.2%), and 121 (50.8%) were females with a median age of 9.0 years. The areas under the ROC curves of Counahan‐Barratt and Bedside Schwartz were equal and 0.89 (with a 95% CI 0.80‐0.97). The areas under the ROC curves were not significantly different in all cystatin C‐based eGFR equations. The highest AUC values for differentiating normal vs abnormal renal functions according to CrCl₂₄ were for the CKiD‐cysC and CKiD‐Scr‐cysC equations.

Conclusions

In our study, compared with creatinine‐based ones, the cystatin C‐based formulas did not show much superiority in predicting eGFR. Still, we think Bedside Schwartz is a good formula to provide ease of use because, in this equation, the constant k is same for all age groups. However, the most valuable equations in determining chronic kidney disease are the CKiD‐cysC and CKiD‐Scr‐cysC equations.

     

胱抑素C对评估肝硬化患者肾小球滤过率的价值

目的 探讨血清胱抑素C(Cys C)浓度检测对评估肝硬化患者肾小球滤过率(GFR)的应用价值.方法 以24h肌酐清除率(Ccr)为GFR标准,对50例肝硬化患者和61例非肝硬化(包括肾功能正常与受损)对照的血清Cys C浓度、血肌酐(Scr)浓度、Cockcroft-Gault(CG)公式估计的Ccr进行比较分析.结果 患者Cys C浓度与对照无显著差异(t=0.48,P＞0.05).以正常参考值上限为诊断肾功能受损的cut off值,Cys C对患者和对照的诊断准确性无明显差异(约登指数分别为0.672、0.666).患者Scr浓度显著低于对照(t=5.24,P＜0.01),CG则显著高于对照(t=4.17,P＜0.01).两者对诊断患者肾功能受损的准确性(约登指数分别为0.272、0.390)均比对照(约登指数分别为0.447、0.472)低.ROC曲线表明,在对照组,Cys C与Scr、CG的诊断准确性相当(Z=1.84、Z=1.39,P均＞0.05),而在患者组,Cys C的诊断准确性显著优于Scr、CG(Z=2.87,P＜0.01;Z=2.28,P＜0.05).结论 Cys C是肝硬化患者较理想的GFR标志物,而Scr、CG在肝硬化中的实用价值不大.     

血清半胱氨酸蛋白酶抑制剂C对高血压患者早期肾损伤的诊断性能评价

目的 评价血清半胱氨酸蛋白酶抑制剂C(Cys C)对高血压患者早期肾损伤的诊断价值,为Cys C在临床的应用提供循证医学证据.方法 对318例原发性高血压并怀疑合并早期肾损伤的患者同时进行血清Cys C和99mTc-二乙三胺五醋酸(99mTc-DTPA)清除率的检测.以99mTc-DTPA清除率为诊断标准将318例患者...     

血清胱抑素C判断移植肾功能的研究

目的:探讨血清胱抑素C(cystatin C)在监测移植肾功能中的价值.方法:23例肾移植患者采用颗粒强透免疫比浊法测定血清cystatin C,同时采用同位素锝[99mTc]-二乙烯三胺五乙酸(diethylenetriaminepentaacetic acid,DTPA)肾动态显像测定移植肾小球滤过率(glomerular filtration rate,GFR),测定血清肌酐(serum creatinine,Scr)及用公式计算内生肌酐清除率(endogenous creatinine clearance,Ccr).测定34名正常健康者作为对照.采用SPSS11软件分析各指标相关性及特异度、灵敏度.结果:cystatin C、Scr、Ccr与GFR的相关性分别是r1 =-0.872(P＜0.001)、r2=-0.687(P＜0.001)、r3=0.634(P=0.002).在判断GFR是否受损时,cystatin C的特异度和灵敏度(100%,94.1%)明显高于Scr(75.0%,70.6%)和Ccr(75.0%,88.2%);在判断肾功能轻度受损时,cystatin C的特异度和灵敏度(100%,88.9%)也比Scr(83.3%,66.7%)和Ccr(83.3%,77.8%)高;尽管在判断肾功能重度受损时,cystatin C的灵敏度(75%)不如Scr(100%),但特异度(100%)仍高于Ccr(88.2%).结论:cystatin C能准确判断移植肾功能,优于Scr和Ccr,具有临床应用价值.     

血清胱抑素C在动态监测移植肾功能中的价值

目的探讨血清胱抑素C（ScysC）在监测肾脏移植患者肾小球滤过率中的应用价值。方法收集26例肾移植病例，分别于术前、术后1、3、5、7d，2周，4周采集血标本，分别测定ScysC、血清肌酐（Scr）、血清尿素（Urea）、内生肌酐清除率（CCr），比较ScysC、Scr与CCr的相关性。结果患者术后随着移植肾功能的恢复，ScysC值持续下降，与术前相比，差异有显著统计学意义（P〈0．01）。与术前相比，术后第1天，ScysC下降达51％，明显早于Scr（下降达40％），移植术前与术后不同时期，患者的ScysC与Scr呈正相关，r=0．945；与CCr呈负相关，r=-0．878。当50ml·min-1．73m。〈CCr≤80ml·min-1．73m-时，ScysC与CCr的相关性明显优于Scr，二者的相关系数分别为-0．856、-0．645（P〈0．05）。其ROC曲线下的面积分别为0．972±0．032、0．926±0．055（P〈0．05）。结论ScysC检测能比较准确评价移植肾的肾小球滤过率，优于Scr，具有临床应用价值。     

Serum cystatin C assay for the detection of early renal impairment in diabetic patients

The ability to assess renal function in diabetes patients rapidly and early is of major importance. This study was designed to determine whether cystatin C can replace serum creatinine as the screening marker for reduced glomerular filtration rate (GFR) in type 2 diabetes patients. The study was performed on 51 type 2 diabetic patients. GFR was estimated by the plasma clearance of (99m)Tc-DTPA. The correlation between (99m)Tc-DTPA clearance and levels of serum cystatin C, serum creatinine, and creatinine clearance was determined. Sensitivity and specificity for the diagnosis of renal impairment (defined as GFR<68 ml/min) were calculated by a receiver operating characteristic (ROC) curve for serum cystatin C, serum creatinine, and creatinine clearance. The correlation coefficients with (99m)Tc-DTPA clearance were -0.744 for serum cystatin C, -0.658 for serum creatinine, and +0.625 for creatinine clearance (P<0.001). With a cutoff value of 68 mL/min, the area under the ROC curve (AUC) was 0.891 for cystatin C, 0.77 for creatinine, and 0.753 for creatinine clearance. The AUC was statistically different between serum cystatin C and creatinine clearance (P<0.05). The ROC plot indicates that cystatin C is superior to serum creatinine and creatinine clearance for detecting impaired GFR. Serum cystatin C appropriately reflects GFR in diabetes, and is more efficacious than serum creatinine and creatinine clearance in detecting reduced GFR in type 2 diabetes patients.     

血清胱抑素C检测对肝肾综合征的诊断价值

目的探讨血清胱抑素C(Cys C)检测对肝肾综合征(HRS)的诊断价值。方法以24 h肌酐清除率(24 h-Ccr)为肾小球滤过率(GFR)标准,将63例晚期肝硬化患者分为两组:GFR<40 ml/min为HRS组,GFR≥40 ml/min为非HRS组。分别测定血清Cys C、血肌酐(Scr),并由MDRD(Modification of Diet in Renal Disease)公式估计肌酐清除率;结果Cys C、MDRD在HRS组与非HRS组(P均<0.01),Scr在HRS和非HRS组间无显著差异(P>0.05)。相关分析显示,Cys C与GFR的相关性最好(r=-0.628,P<0.01),Scr、MDRD与GFR无明显相关(r=-0.355,P>0.05;r=0.059,P>0.775)。ROC曲线表明,Cys C、Scr、MDRD中Cys C的诊断效率最高;结论Cys C是HRS患者良好的GFR标志物,其诊断HRS的能力优于Scr和MDRD。     

胱抑素C在肾脏疾病中的临床应用

目的探讨肾功能损害时血清胱抑素C(Cystatin C,CysC)作为早期敏感标志物对临床诊断的价值。方法采用胶乳增强透射比浊法测定血清CysC的浓度,同时测定血肌酐。结果血清CysC在健康对照组、肾储备下降组、肾功能不全组、肾功能衰竭组、尿毒症组的值分别为(0.76±0.14)、(1.95±0.61)、(2.78±0.86)、(6.23±1.68)、(7.93±1.25)mg/L,随着肾功能的损害程度增加,血清CysC的浓度升高,相邻各组之间CysC差异均有统计学意义(P<0.01)。肾功能正常组血清CysC值与健康对照组相比差异有统计学意义(P<0.05),而两组血清肌酐值相比差异无统计学意义(P>0.05)。结论血清CysC作为反映肾脏损伤的敏感指标,可以替代内生肌酐清除率来判断肾小球滤过率,因此有更广阔的应用前景。     

三种CKD-EPI公式在女性慢性肾病人群中估算肾小球滤过率的比较

目的评价在我国女性慢性肾病(CKD)患者人群中3种CKD-EPI公式计算肾小球滤过率估算值(eGFR)的性能。方法将2010年1月至2015年1月在江苏省中医院肾内科住院的女性CKD患者75例纳入本研究,收集患者的一般资料、血清肌酐(Cr)水平、血清胱抑素C(CycC)水平和99 mTc-DTPA肾动态显像资料。以99 mTc-DTPA肾动态显像法所测肾小球滤过率(GFR)为金标准,用3种CKD-EPI公式(EPI_(Scr)、EPI_(CysC)和EPI_(Scr-CysC))估算eGFR,比较3种公式的偏倚、准确性和95%一致性范围。结果整体公式性能比较,偏倚方面三种公式绝对偏倚比较差异无统计学意义(P0.05);准确度方面:相对偏倚在±30%范围内百分率,CKD-EPICysC与CKD-EPI_(Scr)公式间比较差异有统计学意义(66.67%vs.56.00%,P0.05);一致性方面:BlandAltman散点图显示,CKD-EPI_(Scr-CysC)、CKD-EPI_(Scr)、CKD-EPI_(CysC)公式的95%一致性范围分别为(-33.0%,36.1%)、(-38.4%,35.7%)和(-33.7%,36.6%)。CKD早期,偏倚和准确度方面三个公式比较差异无统计学意义(P0.05),一致性方面:CKDEPI_(Scr-CysC)、CKD-EPI_(Scr)和CKD-EPI_(CysC)公式的95%一致性范围分别为(-33.5%,36.9%)、(-39.0%,36.4%)和(-34.3%,37.5%)。结论尽管CKD-EPI_(Scr-CysC)公式在评估中表现最为优秀,但三种CKD-EPI公式性能差异并不十分明显,在临床实际中仍需综合考虑。     

Evaluation of creatinine,cystatin C and eGFR by different equations in professional cyclists during the Giro d'Italia 3-weeks stage race

Abstract

In this study, creatinine-based equations to evaluate glomerular filtration rate (eGFR) were proposed to more accurately assess kidney function, and cystatin C, a parameter not dependent on muscular mass, was introduced to improve GFR calculation in professional cyclists during a long-lasting race. Nine cyclists participating in the 2011 Giro d'Italia were recruited. Blood and anthropometrical data were collected the day before (T ? 1) the race, on the 12th day (T 12) and on the 22nd day (T 22) of the race. Haemoglobin and haematocrit were registered. Haemodilution was observed at T 12, whilst stabilization was evident at T 22. Creatinine, cystatin C concentrations and eGFR values were not modified during the observed period; only GFR evaluated with the Cockcroft-Gault (CG) formula and expressed as ml/min/1.73 m² significantly decreased (p < 0.05) at T 22 in comparison with T ? 1, probably as a consequence of weight decrease. Cystatin C levels were in the reference range, while creatinine concentrations were lower. The lowest eGFR values were observed with CG normalized and the Modification of Diet in Renal Disease (MDRD) formulas. A good correlation was observed between the MDRD and the Chronic Kidney Disease-Epidemiology Collaboration (CKD-EPI) equations and between CG normalized and both CKD-EPI and MDRD formulas. The worst correlation was registered between CKD-EPI creatinine and cystatin C and all the other equations. In conclusion, adaptive mechanisms of renal function allow athletes to maintain stable creatinine, cystatin C and eGFR values during a long-lasting race. The use of GFR equations to evaluate general health status of sportsmen should be recommended with caution, considering also weight modification during competition.     

Serum cystatin C as a better marker of vancomycin clearance than serum creatinine in elderly patients

OBJECTIVES: The purpose of this study is to assess the usefulness of the concentration of cystatin C (Cys-C) in serum for predicting the clearance of vancomycin (CLvcm) compared with the serum concentration of creatinine (SCr) in the elderly. METHODS: Thirty-nine serum samples were obtained from 24 elderly patients (65 years and older). Creatinine clearance (CLcr) and the glomerular filtration rate calculated from the concentration of Cys-C (GFRcys-c) were estimated using Cockcroft & Gault's formula and Larsson's formula, respectively. RESULTS: The correlation constant for CLvcm and the reciprocal of Cys-C (p=0.883) was significantly higher than that for CLvcm and the reciprocal of SCr (p=0.575, p<0.005). GFRcys-c was strongly correlated with CLvcm (p=0.883) and the constant was significantly higher than that for the correlation between CLvcm and CLcr (p=0.684, p<0.05). These results suggest that the serum concentration of Cys-C is a more reliable marker for predicting CLvcm than is SCr in elderly patients.     

Evaluation of the clinical application of cystatin C, a new marker of the glomerular filtration rate, for the initial dose-setting of arbekacin

Objective:  Recent studies have shown that serum cystatin C is a better marker for measuring the glomerular filtration rate (GFR) than the conventional method, using serum creatinine concentration. The purpose of this study is to evaluate the clinical application of serum cystatin C as a marker of GFR to determine the initial dosage of arbekacin, an antibiotic primarily excreted via the kidneys. In this study, the predictability of serum arbekacin peak and trough concentrations were assessed using estimated population mean GFR values calculated from either serum creatinine (Cockcroft–Gault equation) or cystatin C (Sjöström equation) concentrations. Method:  Ninety‐five patients treated with arbekacin for methicillin‐resistant Staphylococcus aureus infection were divided into three groups according to their GFR values estimated by the serum cystatin C concentration as follows: normal to mild (GFR > 70 mL/min, n = 40), moderate (30 ≤ GFR ≤ 70 mL/min, n = 41) and severe (GFR < 30 mL/min, n = 14) renal impairment. Result:  The mean GFR (±SD) of 95 patients predicted by serum cystatin C concentration (64·6 ± 30·6 mL/min) was significantly lower (P < 0·001) than predicted by serum creatinine concentration (77·4 ± 43·9 mL/min). Prediction (difference of mean prediction error, ΔME) of the serum arbekacin concentration using the estimated GFR based on the serum cystatin C concentration was significantly less biased at the peak and trough concentrations than those determined using serum creatinine concentration. The accuracy of prediction (difference of the mean absolute error, ΔMAE) using serum cystatin C concentration was significantly better than with serum creatinine for both serum peak and trough concentrations in patients with moderately decreased GFR. However, there were no significant differences in the ΔMAE of normal to mild and severe renally impaired patients. Conclusion:  These results suggest that serum cystatin C is a useful marker of GFR for determining the initial dosage of arbekacin, especially in patients with moderate impairment of renal function.     

根据血清胱抑素C浓度推测肾小球滤过率的临床应用

目的评价血清胱抑素C(CysC)替代内生肌酐清除率(Ccr)作为推测肾小球滤过率(GFR)标志物的可行性.方法应用留尿法测定120位患者的Ccr,同时测定血清Cys C的浓度.并按Ccr测量值的大小将患者分为3组,将3组的Ccr同血清CysC浓度的样本均数进行比较.结果3组Ccr与血清CysC的样本均数相比较无显著性差异,3组的相关系数均在0.9以上,有着很好的相关性.结论血清CysC作为GFR的内生标志物,由于其无需留尿、方法简单而优于Ccr,在临床应用Cys C替代Ccr是可行的.     

半胱氨酸蛋白酶抑制剂C对肝硬化患者肾功能早期损害的实验评价

目的探讨血清半胱氨酸蛋白酶抑制剂C(Cys C)对肝硬化患者肾功能早期损害的诊断价值。方法测定67例肝硬化患者和32名健康对照者的血清肌酐(Cr)、尿素(Urea)、肌酐清除率(Ccr)和Cys C水平,并将患者按性别、Ch ild-Pugh分级或Ccr水平进行分组评价。结果肝硬化患者血清Ccr和Cys C水平与对照组比较差异有显著性(P<0.001),但Cr和Urea差异无显著性。不同性别患者Ccr、Cr和Cys C水平与对照组比较差异有显著性(P<0.05~0.001),但Urea无差异。肝硬化患者Ch ild-Pugh分级各亚组Ccr、Cr、Urea和Cys C水平与健康对照组比较差异有显著性(P<0.05~0.001)。以Ccr 70 m l/m in为界点将患者分为Ⅰ和Ⅱ亚组,并与对照组比较,结果表明仅Cys C水平差异有显著性(P<0.001),Cys C水平Ⅰ和Ⅱ2亚组间差异也有显著性(P<0.001)。受试者工作特征曲线(ROC曲线)显示Cys C诊断有效性优于Cr和Urea。结论血清Cr和Urea难以对肝硬化患者肾功能轻度受损进行诊断,Ccr虽能作出早期指示,却过高估计试验结果,而Cys C能较准确地作出早期检测,提示其可能是潜在的肝硬化患者肾功能早期损害的指标。     

检测血清胱抑素C诊断急性肾衰竭的研究

目的:探讨血清胱抑素C(cystatin C)在诊断急性肾衰竭(acute renal failure,ARF)中的临床价值。方法:收集215例ICU病人的血标本,用酶法测定血清肌酐(serum creatinine,Scr),用颗粒增强透射免疫比浊法测定血清cystatinC,用Cockroft-Gault公式计算肾小球滤过率(glomerular filtration rate,GFR),ARF诊断按ADQI标准。比较ARF病人与非ARF病人上述各指标。结果:41例ARF病人(观察组)血清cystatinC水平较174例非ARF病人(对照组)明显升高(P<0·01);ARF病人血清cys-tatinC与Scr呈正相关(r1=0·747,P<0·001)、与GFR呈负相关(r2=-0·808,P<0·001);以Scr升高达到或超过150%作为ARF的诊断标准时,ROC曲线分析显示血清cystatinC对ARF的诊断准确度高(曲线下面积为0·983)。结论:ARF时血清cystatinC明显升高,cystatinC可作为ICU危重病人并发ARF的诊断指标之一。     

血清胱抑素C与早期高血压肾损害的相关性研究

目的探讨血清胱抑素C(Cys C)在高血压早期诊断中的应用价值,并分析Cys C与高血压肾损害的相关性。方法选择78例高血压患者,根据内生肌酐清除率(Ccr),将其分为A组32例(Ccr正常)和B组46例(Ccr<80 mL/min),并选择同期进行体检的健康者30例作为C组,观察3组患者血清肌酸酐(Scr)、血尿素氮(BUN)、β2微球蛋白(β2-MG)及Cys C水平的变化。结果 A组患者Scr、BUN及β2-MG水平均明显低于B组,但BUN和Cys C水平明显高于C组;B组患者Scr、BUN、Cys C和β2-MG水平均明显高于C组。Spearman相关性分析表明,A组Cys C与Scr、BUN存在显著正相关;B组CysC、β2-MG与Scr、BUN存在显著正相关。结论血清Cys C与肾损害明显相关,可作为高血压肾损害的早期诊断指标。     

基于血清胱抑素C的成年中国人肾小球滤过率估算公式临床对比研究

目的 探讨基于血清胱抑素C(SCys C)的成年中国人肾小球滤过率估算公式(SCysCAC)的临床价值.方法 采用前瞻性对照研究方法,选择2011年1月至12月96例非透析肾脏病住院患者,按入院时肾功能分为不全组(RFI,54例)和正常组(RFN,42例),用双血浆法99m Tc-二乙三胺五乙酸(99mTc-DTPA)清除率检测肾小球滤过率( Tc-GFR),同期测定SCys C、血清肌酐(SCr)与尿素氮(BUN),并以SCysCAC、Arnal-Dade、Grubb、Filler、Grubb、Hojs、Larsson、Macisaac、Rule 9个公式估算肾小球滤过率(GFR),对比不同肾功能组各公式肾小球滤过率估算值(eGFR),并分别与Tc-GFR进行相关性分析研究.结果 在RFI或RFN患者中,SCysCAC、Arnal-Dade、Larsson、Rule公式的eGFR(ml·min-1· 1.73 m-2)始终与Tc-GFR接近(RFI组:37.96±32.65、33.69±25.24、34.16±33.65、33.02±30.88比36.21±31.16; RFN组:112.99±39.26、101.86±72.29、102.69±71.78、99.12±69.54比110.54±48.98,均P＞0.05).在RFI或RFN患者中,SCysCAC、Larsson、Arnal-Dade公式的eGFR与Tc-GFR的差值绝对值无统计学差异,三者中以SCysCAC-eGFR与Tc-GFR的差值绝对值最小,表明3个公式的eGFR均能准确反映GFR,而以SCysCAC最佳.相关性分析显示,各公式的eGFR均在一定程度上准确反映了肾小球功能或GFR.结论 SCysCAC公式为快速、准确估算GFR的方法,可在临床上推广使用.     

光抑素C与血肌酐对2型糖尿病患者肾小球滤过功能评价比较

目的 比较光抑素C(Cystatin C)和血清肌酐及8小时肌酐清除率，评价其对2型糖尿病患者肾小球滤过率(GFR)的判断价值。方法 选择80例2型糖尿病患者，检测其血肌酐、肌酐清除率、尿微量白蛋白排泌率(UAER)及Cystatin C水平，同时通过^99mTc-DTPA排泌率，应用Gates法计算GFR。结果 Cystatin C水平随GFR下降逐渐升高。相关性分析示Cystatin C与GFR呈相关性(r=-0．663，p=0．000)，明显高于肌酐(r=-0．444，P=0．009)及8小时肌酐清除率(r=0．300，P=0．000)。ROC曲线分析示Cystatin C具有更大的曲线下面积(AUC)，敏感性(82％)、特异性(96％)均好，而肌酐特异性好(98％)、敏感性差(20％)，8小时肌酐清除率敏感性(68％)、特异性(79％)均不理想。Cystatin C诊断精确性(80％)明显高于肌酐(63％)。结论 Cystatin C是反映GFR的更敏感指标，可更早、更准确地反映2型糖尿病患者GFR的变化。     

血清胱抑素C在ICU危重患者急性肾损伤早期诊断中的价值

目的：探讨血清胱抑素C在重症患者伴有急性肾损伤早期诊断中的价值。方法：对ICU中39例发生AKI者（观察组）及32例未发生AKI者（对照组）,采用酶法测血清肌酐水平,透射比浊法测血清胱抑素C水平,采用ROC评价血清胱抑素C的诊断价值,应用Cockroft-Gault公式估算肾小球滤过率。结果：观察组患者血清胱抑素C较对照组明显升高（P〈0.05）,观察组血清胱抑素C与血清肌酐呈正相关关系（r=0.683,P〈0.05）,与肾小球滤过率呈负相关关系（r=-0.346,P〈0.05）。ROC得出血清胱抑素C最佳截断值为1.65mg/L,肌酐最佳截断值为128.8μmol/L。急性肾损伤1期患者血清胱抑素C灵敏度（85%）,高于血清肌酐灵敏度（70%）,且出现异常的时间要早于肌酐。急性肾损伤2、3期患者间灵敏度比较差异无统计学意义（P〉0.05）。结论：在危重患者中血清胱抑素C可作为急性肾损伤肾小球滤过率的内源性标志物,对急性肾损伤患者早期诊断有重要作用。