血清胱抑素C:一种简便的肾小球滤过率指标

肾小球滤过率(glomerular filtration rate,GFR)是反映肾功能最重要的指标.目前临床上常用来反映肾小球滤过功能的指标如血肌酐(Scr)、内生肌酐清除率(Ccr)等都有一定的局限性,且不同程度地受到一些肾内或肾外因素的干扰.为此寻找新方法来测定肾功能,是众所关心的问题.近年来,测定血清胱抑素C(Cystatin C)来反映GFR水平,受到人们关注.     

血清胱抑素C在评价慢性肾脏病患者肾小球滤过率中的价值

目的：探讨血清胱抑素C（CystC）在评价慢性肾脏病（CKD）患者肾小球滤过率中的临床价值。方法：选取2009年4月～2009年11月住院的CKD患者76例,检测其血清CystC浓度,血清肌酐浓度（Scr）,以99mTc-二乙三胺五醋酸（99mTc-DTPA）法测定肾小球滤过率（GFR）,并用简化MDRD和Cockcroft-Gault（C-G）方程分别估测GFR（M-GFR,C-GFR）,以99mTc-GFR作为金标准,比较不同CKD分期间各指标间的相关性及其敏感度和特异度。结果：患者血清CystC、Scr、C-GFR、M-GFR与99mTc-GFR的相关系数分别为-0.81、-0.73、0.90、0.89,P均〈0.01,CystC在CKD1～3期与99mTc-GFR均有相关性,相关系数分别为-0.57（P〈0.05）,-0.44（P〈0.05）,-0.74（P〈0.01）,但在4～5期两者无明显相关关系（相关系数-0.30,P〉0.05）而Scr、C-GFR、M-GFR与99mTc-GFR仅在CKD3期患者中有相关性;在CKD1期患者中,CystC的敏感性和特异性均高于C-GFR和M-GFR。结论：血清CystC是一个反映CKD患者肾功能的较为敏感的指标,尤其在早期CKD患者中应用价值更大。     

血清胱抑素-C是反映肾小球滤过功能的敏感指标

目的探讨测定血清胱抑素C(Cystatin C)浓度来判断肾小球滤过率的准确性与敏感性。方法对32例各种原因可能或已经肾功能轻-中度受损的患者，应用乳胶颗粒增强比浊法(PET)测定其血清CystatinC浓度，采用^99Tc-DTPA血浆清除率测定其肾小球滤过率(GFR)，同时测定血尿素氮(BUN)、血肌酐(SCr)，并根据Cockcroft-Cault公式计算肌酐清除率。结果血清Cystatin C浓度与上述指标均有相关性，并有显著性意义。血清Cystatin C比SCr与用^99Tc-DTPA测定的GFR有更好的一致性。结论血清Cystatin C浓度是一个反映肾小球滤过功能准确、敏感的指标。     

血清胱抑素C：在肌酐盲范围检测GFR的标志物

近年来实验和临床研究表明，血清中胱抑素与传统的血肌酐测定相比，是更好的检测肾小球滤过率（GFR）的标志物，对它的检测拟可作为早期而敏感的GFR指标。     

血清胱抑素C:在肌酐盲范围检测GFR的标志物

近年来实验和临床研究表明 ,血清中胱抑素与传统的血肌酐测定相比 ,是更好的检测肾小球滤过率 (GFR)的标志物 ,对它的检测拟可作为早期而敏感的GFR指标。     

肾移植术后随访中检测受者血清胱抑素C的临床价值

目的 探讨血清胱抑素C(SCys C)浓度检测能否作为肾移植受者随访中移植肾功能测定的理想指标.方法 选择肾移植术后接受长期随访的受者70例,于随访当日检测受者SCys C和血清肌酐(SCr)水平,同时用99mTc-DTPA肾动态显像测定肾小球滤过率(GFR),比较SCys C和SCr与GFR的相关性,并应用受试者工作特征曲线(ROC曲线)评价两者在诊断移植肾功能轻度损伤(GFR＜1 ml/s)中的效果.结果 随访的肾移植受者中,SCys C和SCr与GFR均呈负相关,相关系数分别为-0.82和-0.66(P＜0.01).SCys C用于诊断移植肾功能轻度损伤的敏感度、特异度和阳性预测值(PPV)均高于SCr.SCys C的ROC曲线下面积高于SCr(分别为0.935和0.877),但两者比较,差异无统计学意义(P＞0.05).结论 在肾移植术后的随访中,受者SCys C与GFR的相关性比SCr更高,可作为评估移植肾功能的较理想指标.     

血清胱抑素C在肾移植患者肾功能监测中的作用

近年来的研究表明,血清胱抑素C在反映移植肾滤过功能方面优于血清肌酐等传统的检验项目,有助于更及时地发现急性排斥反应或药物性肾中毒。血清胱抑素C测定方法简便、迅速、价格适中,适合临床应用。     

测定血清胱抑素-C对评估肾功能的意义

通常认为肾小球滤过率(GFR)是反映。肾脏功能的最佳指标；菊粉清除试验是估量GFR的“金指标”，但由于操作繁琐等原因，不适合常规应用。目前临床上普遍采用血清肌酐(SCr)和肌酐清除率(Ccr)估计GFR，但其准确性和灵敏度不理想。     

动态监测血清胱抑素 C 评价肾移植术后肾功能的改变

目的 监测肾移植受者血清胱抑素C(Cys C)浓度以评估移植肾功能的改变. 方法 监测58例肾移植成功受者术前及术后不同时间的血清Cys C、肌酐(SCr)、β2-微球蛋白(β2-MG)和尿素氮(BUN)水平;并于术后第7天使用99mTc-DTPA测定受者肾小球虑过滤(GFR),比较其与上述四项指标的相关性.以GFR=1.5 ml/s为临界值,绘制ROC曲线,比较各项检测指标鉴别轻度与中重度肾功能损伤的诊断性能.计算受者不同时间段血清Cys C及SCr变异系数及其比值(R值). 结果 Cys C于术后第1天下降达48.1%,明显大于其他指标的下降幅度.血清Cys C、SCr、β2-MG和BUN与GFR相关系数依次为0.876、0.691、0.589和0.516.血清Cys C、SCr、β2-MG和BUN的诊断性能:敏感性分别为91.3%、87.2%、82.6%和87.0%;特异性分别为80.0%、69.2%、71.4%和42.9%;阳性预期值分别为82.0%、73.7%、74.3%和60.4%;阳性似然比分别为4.81、2.83、2.87和1.53;ROC曲线下面积(AUC)分别为0.914、0.828、0.803和0.765.SCr的变异系数显著小于Cys C(P＜0.01),Cys C＜2 mg/L的受者R值大多＜1,Cys C＞2 mg/L的受者,伴随Cys C水平升高,R值趋近于1. 结论 Cys C与GFR相关性最好;Cys C的诊断性能及准确性均优于其他指标,即使肾功能有微小损伤,Cys C也会有显著改变.因此,肾移植术后动态监测Cys C对于及时判断移植肾存活及肾微小损伤时肾功能的改变优于其他指标.     

肾移植患者血清胱抑素C与肌酐清除率相关性的研究

目的探讨肾移植患者血清胱抑素C（SCysC）浓度作为移植肾功能测定指标的可行性和临床应用价值。方法采用颗粒增强透射免疫比浊法（PETIA）分别检测39例初次肾移植患者在术前、术后1周和4周的SCysC水平,并与血清肌酐（Scr）、内生肌酐清除率（Ccr）进行比较分析。结果肾移植术前与术后,患者的SCysC与Scr、Ccr都具有很好的相关性。SCysC与Scr呈正相关（术前r=0.849;术后r=0.940）;与Ccr呈负相关（术前r=-0.857;术后r=-0.876）;按Ccr分组的统计分析结果显示：不同肾功能水平的SCysC与Ccr的相关性均较Scr与Ccr的相关性相似或更佳。当50≤Ccr〈80mL/（min.1.73m^2）时,SCysC与Ccr的相关性要明显优于Scr与Ccr的相关性（P〈0.05）。结论在肾移植患者中,SCysC浓度与Scr浓度和Ccr有较好的相关性,可成为评估移植肾功能的较理想指标。     

应用血清西司他汀浓度测定肾小球滤过率的相关研究

目的：提供临床上准确，简便测定肾小球滤过率的方法。方法：应用乳胶颗粒增强比浊法（PET）测定79例有肾脏损害患者血清西司他汀（cystatin C)浓度，同时测定血尿素氮（BUN），血肌酐（Scr),24h肌清除率（24h Ccr)和采用Cockcroft-Cault公式计算肌酐清除率（Ccockcroft)，结果除BUN外，以上指标与cystatin C均有相关关系，并有显著性意义。结论：cystatin C浓度检测在临床上提供一种快速，准确和简捷的测定肾小球滤过率的方法，能发现早期肾脏损害和肾功能改变。     

Estimated glomerular filtration rates are higher when creatinine-based equations are compared with a cystatin C-based equation in coronavirus disease 2019

Objectives

Estimations of glomerular filtration rate (eGFR) are based on analyses of creatinine and cystatin C, respectively. Coronavirus disease 2019 (COVID-19) patients in the intensive care unit (ICU) often have acute kidney injury (AKI) and are at increased risk of drug-induced kidney injury. The aim of this study was to compare creatinine-based eGFR equations to cystatin C-based eGFR in ICU patients with COVID-19.

Methods

After informed consent, we included 370 adult ICU patients with COVID-19. Creatinine and cystatin C were analyzed at admission to the ICU as part of the routine care. Creatinine-based eGFR (ml/min) was calculated using the following equations, developed in chronological order; the Cockcroft–Gault (C-G), Modified Diet in Renal Disease (MDRD)1999, MDRD 2006, Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI), and Lund–Malmö revised (LMR) equations, which were compared with eGFR calculated using the cystatin C-based Caucasian Asian Pediatric Adult (CAPA) equation.

Results

The median eGFR when determined by C-G was 99 ml/min and interquartile range (IQR: 67 ml/min). Corresponding estimations for MDRD1999 were 90 ml/min (IQR: 54); MDRD2006: 85 ml/min (IQR: 51); CKD-EPI: 91 ml/min (IQR: 47); and for LMR 83 ml/min (IQR: 41). eGFR was calculated using cystatin C and the CAPA equation value was 70 ml/min (IQR: 38). All differences between creatinine-based eGFR versus cystatin C-based eGFR were significant (p < .00001).

Conclusions

Estimation of GFR based on various analyses of creatinine are higher when compared with a cystatin C-based equation. The C-G equation had the worst performance and should not be used in combination with modern creatinine analysis methods for determination of drug dosage in COVID-19 patients.     

Effect of malnutrition on serum creatinine and cystatin C levels

The concentration of cystatin C has been shown to be independent of age, gender and height, but the effect of malnutrition has not been studied. Levels of serum creatinine and cystatin C were estimated in 77 malnourished and 77 normally nourished boys between 2 years and 6 years of age without evidence of renal disease. The mean (95% confidence interval) serum creatinine level in the malnourished boys was significantly lower than that in the normally nourished boys [0.42 (0.38–0.45) mg/dl and 0.51 (0.48–0.55)] mg/dl, respectively, (P < 0.01)]. The mean level of serum cystatin C was 1.05 (0.94–1.17) mg/l and 1.12 (1.01–1.24) mg/l, respectively, in normally nourished and malnourished boys (P = 0.35). Mean glomerular filtration rate (GFR) estimated by the Schwartz equation in the malnourished boys was significantly higher than that in normally nourished children [141.8 (123.3–160.2) ml/min per 1.73 m² body surface area and 119.4 (109.3–129.5) ml/min per 1.73 m² body surface area], respectively (P = 0.04). However, the mean cystatin C-derived GFR was similar in the malnourished and normally nourished boys [99.70 (85.8–113.5) ml/min per 1.73 m² and 109.2 (94.4–124.0) ml/min per 1.73 m²], respectively (P = 0.35). The mean bias between GFR estimates using Bland and Altman analysis was greater in the malnourished children than in the normally nourished children (32.3% and 17.6%, respectively) (P = 0.15). Serum creatinine levels are lower in malnourished children and lead to overestimation of GFR, while cystatin C levels are unaffected.     

Cystatin C as a marker for glomerular filtration rate in pediatric patients

Cystatin C is a non-glycated 13-kilodalton basic protein produced by all nucleated cells. The low molecular mass and the basic nature of cystatin C, in combination with its stable production rate, suggest that the glomerular filtration rate (GFR) is the major determinant of cystatin C concentration in the peripheral circulation. Recently published studies have shown that cystatin C correlates more strongly than creatinine with GFR measured using the ⁵¹Cr-EDTA clearance. The aim of this study was to evaluate serum cystatin C as a marker for GFR in children. GFR was determined on medical indications using the ⁵¹Cr-EDTA technique in pediatric patients (2–16 years) in our renal unit. Simultaneously their cystatin C and creatinine concentrations were also measured. Of our 52 patients, 19 had a reduced renal function (<GFR 89 ml/min per 1.73 m²) based on the ⁵¹Cr-EDTA clearance. The correlation of cystatin C with the isotopic measurement of GFR tended to be stronger (r=0.89, P=0.073) than that of creatinine (r=0.80). Receiver operating characteristic analysis showed that the diagnostic accuracy of cystatin C was better (P=0.037) than that of creatinine in discriminating between subjects with normal renal function and those with reduced GFR. This study demonstrates that serum cystatin C has an increased diagnostic accuracy for reduced GFR when compared with serum creatinine. Hence, cystatin C seems to be an attractive alternative for the estimation of GFR in children. Received: 13 May 1998 / Revised: 22 September 1998 / Accepted: 22 October 1998     

Validation of child serum creatinine-based prediction equations for glomerular filtration rate

Equations for estimating glomerular filtration rate (GFR) are vital in caring for patients with renal disease and the current standard, the Schwartz formula, lacks precision. We evaluated several child serum creatinine-based GFR prediction equations. Subjects aged 2–21 years who underwent iothalamate GFR (IoGFR) testing between 1999 and 2004 were studied retrospectively. GFR was estimated using: (1) Schwartz formula (SchwartzGFR), using a local k value; (2) Schwartz model (SchwartzMod) using regression-derived coefficients; (3) Leger GFR (LegerGFR) using original coefficients; and (4) Leger model (LegerMod) using regression-derived coefficients. Bias, precision, and diagnostic characteristics were evaluated. There were 195 subjects [61% male; mean (SD) age 12.4 (4.5) years; mean (SD) IoGFR 78.9 (33.4) ml/min per 1.73 m²]. Only the LegerGFR overestimated IoGFR (5.5 ml/min per 1.73 m²). Precision for all formulae was poor (95% limits of agreement approximately −40 to 40 ml/min per 1.73 m²), but ≥72% of estimates were within 30% of IoGFR. Sensitivities for detecting IoGFR <30 and 90 ml/min per 1.73 m² were highest using the SchwartzGFR (80%) and SchwartzMod (90%), respectively. The LegerGFR was most specific. Using local coefficients, the Schwartz and Leger models were imprecise estimates of GFR, but the Schwartz model was most unbiased and sensitive. Future research should derive more precise equations for GFR in children. The work was performed at McGill University Health Centre, Montreal, Quebec, Canada. There were no direct sources of support for this research. However, a significant portion was performed while Dr. Zappitelli was receiving research fellowship funding by the Kidney Research Scientist Core Education and National Training (KRESCENT) Program (Kidney Foundation of Canada, Canadian Society of Nephrology, and Canadian Institutes of Health Research).     

CKD—EPI方程在慢性肾脏病患者中的适用性

目的探讨慢性。肾脏病流行病学合作研究（CKD-EPI）方程对评估中国人肾小球滤过率（GFR）的适用性。方法选择CKD患者42例,对其以CKD-EPI方程估算GFR（eGFR）与BSA标准化的99mTc-DTPA肾动态显像法测定的GFR（sGFR）进行比较。结果eGFR与sGFR呈正相关（r=0．868,P〈0．01）;eGFR的15％、30％及50％符合率分别是23．8％、40．5％和64．3％,eGFR与sGFR平均偏差5．46ml／min。结论CKD-EPI方程可广泛应用于评估CKD患者GFR,但仍然存在偏差,需进行大规模试验并根据CKD不同分期进行适用性研究。     

应用~(99m)Tc-DTPA摄取率测定肾小球滤过率与传统方法计算肌酐清除率的比较

目的 :评估在中国慢性肾脏病人中应用肌酐清除率 (Ccr)估计肾小球滤过率 (GFR)的有效性 ,并介绍由ToTo等人推导出的一条计算Ccr的新公式 (我们简称ToToes’公式 )。方法 :研究中国慢性肾脏病人 10 0例 (男 5 0例 ,女 5 0例 )。应用99mTc-DTPA摄取法 (Gates法 )测定GFR ;采用三种方法根据血肌酐 (Scr)计算Ccr :2 4hCcr(2 4hCcr) ,Cockcroft-Gault公式计算Ccr(Ccr -CG)及用ToToes’公式计算Ccr(Ccr -TT) ;然后将Ccr与测定的GFR比较 ,其准确度用二者的差值 (△GFR =GFR -Ccr)和比值 (GFRratio =Ccr/GFR)来评估 ,可靠性用决定系数r2 和平方误差的联合平方根 (CRMSE)来评估。结果 :男性组 :(1)△GFR :Ccr -CG≈CCR -T <2 4hCcr ;(2 )GFRratio :Ccr -CG≈Ccr -TT >2 4hCcr ;(3)r2 :Ccr -CG >Ccr -TT >2 4hCcr ;(4 )CRMSE :Ccr -CG≈Ccr -TT <2 4hCcr。女性组 :(1)△GFR :Ccr-TT Ccr -CG >2 4hCcr;(3)r2 :Ccr -CG >Ccr -CG≈ 2 4hCcr;(4 )CRMSE :Ccr-TT 相似文献   

Clinical assessment of serum cystatin C as a marker of glomerular filtration rate in patients with various renal diseases

Background. Recent reports have raised questions about the validity of estimating glomerular function and changes in glomerular function from measurements of serum creatinine. To evaluate the clinical usefulness of serum creatinine levels in terms of estimation of glomerular filtration rate (GFR), we determined serum cystatin C levels in 152 patients with various renal diseases and compared them with serum creatinine levels. Methods. Serum cystatin C levels were measured by particle-enhanced immunonephelometry. Two-h creatinine clearance (Ccr) was used as an indicator of GFR. Results. There was a significant positive correlation between serum cystatin C and creatinine levels (r = 0.941) in patients with various renal diseases. Serum cystatin C and creatinine were inversely correlated to Ccr. The overall correlation between serum cystatin C and Ccr was slightly stronger than that between serum creatinine and Ccr. In the patient group with a critical Ccr level (Ccr, 60–80 ml/min per 1.48 m²), the correlation between the reciprocal serum cystatin C levels and Ccr (r = 0.441) was significantly stronger (P < 0.01) than that between the reciprocal serum creatinine levels and Ccr (r = 0.212). A mild reduction of Ccr was detected more easily by serum cystatin C than by serum creatinine, as the clinical sensitivity and specificity of serum cystatin C were superior to that of serum creatinine. Conclusions. The cystatin C assay by particle-enhanced immunonephelometry was found to be a sensitive, fully automated, and rapid method. Serum cystatin C appears to be a promising marker of GFR in patients with impaired renal function. Its diagnostic potential was slightly superior to that of serum creatinine in adults with various renal diseases. Received: October 7, 1998 / Accepted: November 4, 1999     

CKD—EPI方程在我国慢性肾脏病不同分期中的应用

目的探讨慢性肾脏病流行病学合作研究（CKD-EPI）方程在中国人CKD的不同分期评估肾小球滤过率（GFR）的适用性。方法选择我院肾内科CKD患者98例。将CKl2vEPI方程估算的GFR值用体表面积（BSA）标准化得出估算GFR（eGFR）,与BsA标准化的肾动态显像法（^99Tc-DTPA）检测的GFR（sGFR）用K／DOOI指南推荐的方法进行比较。结果相关性分析得出eGFR与sGFR呈正相关（r=0．847,P〈0．01）;eGFR的15％、30％及50％符合率分别是31．6N、59．2％和85．7％,eGFR估计值与sGFR平均偏差2．56ml／min。CKD各期偏差均无统计学意义,在CKD2～5期,偏差较小;CKD1期,偏差略大,偏差值为（13．22±22．41）,但偏差无统计学意义（P〉0．05）。结论CKD-EPI方程可广泛应用于我国CKD各期患者评估GFR,具有较小的偏差,较高的准确性。CKD-EPI方程在评估较高的GFR时,可能存在矫枉过正,高估GFR。