中国肾小球滤过率评估方程在慢性肾小球肾炎患者的适用性评价

目的：评价现有在中国人群基础上开发的肾小球滤过率（GFR）评估方程在慢性肾小球肾炎患者的适用性。方法：选择143例慢性肾小球肾炎患者,用中国方程、瑞金方程、MDRD1方程和简化MDRD方程,分别计算GFR值,与^99mTc—DTPA测的GFR（sGFR）进行比较。结果：Bland—Altman分析显示MDRD1方程和瑞金方程估计的GFR和sGFR的一致性较好,但所有各方程估计的GFR和出FR的一致性限度均超过事先规定的专业界值。线性回归结果显示,MDRD1方程和瑞金方程估测的GFR与X轴的斜率较其他方程更接近0。在所有方程中,MDRD1方程和中国9方程偏差较小,瑞金方程估测GFR30％符合率和50％符合率均最高,但瑞金方程估测GFR30％符合率依然低于70％。在慢性肾脏病不同分期中,瑞金方程和MDRD1方程较其他方程有较小的偏差和更优的准确性。结论：当血肌酐的测定方法为酶法时,如直接应用现有在中国人群基础上开发的肾小球滤过率评估方程评估慢性肾小球肾炎患者肾功能,可能会产生明显的偏差。     

不同肾小球滤过率估算公式在老年人肾功能评估中适用性的比较

目的比较不同肾小球滤过率估算公式在老年人肾功能状况评估中的适用性及其与内生肌酐清除率（Ccr）的相关性。方法选择720例老年内科患者,应用Cockcroft-Gault（C-G）公式、肾脏病膳食改良试验（MDRD）7（M7）公式、MDRD（Ma）公式及我国改良MDRD（Me）公式计算估计肾小球滤过率（eGFR）。分析C-G公式与其他公式计算的eGFR值与年龄和Ccr值的相关性。结果Ccr值和C-G公式计算的eGFR值均随年龄增长明显下降,与年龄呈显著负相关;其他公式计算的eGFR值与年龄均无相关性。本组患者的总体Ccr值为（50．32±23．64）ml·min-1·（1．73m2）-1;C-G公式计算的eGFR值为（45．45±18．46）ml·min-1·（1．73m2）-1,与Ccr值最为接近;其他公式的测定值均显著高于Cer值。在总体和CKD3～4期患者,C-G公式计算的eGFR值与Ccr值的相关性均高于其他公式。结论C-G公式计算的eGFR值与年龄和Ccr值的相关性最好,C-G公式可代替Ccr评估老年人的肾功能状况。     

不同肾小球滤过率评估方程在慢性肾脏病患者中适用性的比较

目的：比较肾脏病膳食改良试验（MDRD）和Cock—croft—Gault（cG）方程以及国内的两个校正MDRD方程对慢性肾脏病（CKD）患者预测肾小球滤过率（GFR）的适用性。方法：选择2006年--2008年646例非透析CKD患者,用简化MDRD和CG公式以及两个国内校正公式（MDRD1、MDRD2）计算估测GFR（eGFR）,并进行相关性、偏离度、精密度的比较,以及比较不同CKD分期估测GFR的准确性、偏差中位数。结果：（1）MDRD1方程不论在精密度、偏离度、绝对偏差方面都明显优于其他的方程。（2）MDRD1方程的30％和50％准确率上明显高于其他方程（P〈0．05）。（3）CG明显低估了GFR,MI）RD和MDRD2在Ⅳ期低估了GFR,在Ⅱ、Ⅲ期高估了GFR,MDRD1在Ⅲ期高估了GFR。结论：经过校正的MDRD1方程明显优于CG、简化MDRD、MDRD2方程。     

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。     

MDRD方程预测肾小球滤过率的临床应用评价

目的以99mTc-DTPA血浆清除率为标准,对MDRD方程7、简化MDRD方程和Cockcroft-Gault方程进行比较,评价3个方程在慢性肾脏病患者中的应用.方法选择慢性肾脏病患者199例,年龄均＞18岁,诊断均符合美国NKF-K/DOQI关于慢性肾脏病定义,且无肾功能急性恶化因素,无水肿和肌肉萎缩或肢体缺如.记录性别、年龄、身高和体重.用MDRD方程7和简化MDRD方程计算GFR,Cockcroft-Gault方程计算Ccr后用体表面积标准化.弹丸式静脉注射1 ml 185 MBq/ml99mTc-DTPA,分别于注射后2 h和4 h取血,测量其血浆放射性计数,并检测血清肌酐、尿素、白蛋白,计算99mTc-DTPA的血浆清除率,并用体表面积标准化作为GFR测量值.各方程计算值分别与GFR测量值进行比较.结果199例中男112例,女87例,平均年龄(51.58±14.9)岁.慢性肾脏病的病因包括肾积水63例,原发或继发性肾小球疾病46例、慢性肾小管间质疾病16例、其它或病因不明74例.MDRD方程7、简化MDRD方程和Cockcroft-Gault方程的估计值与GFR测量值的相关系数(r)分别为0.84,0.81和0.82;3个方程的计算值均显著低于GFR测量值,MDRD方程7、简化MDRD方程与测量值的偏差[分别为-4.37和-4.83 ml·min-1(1.73m2)-1]和绝对偏差[分别为11.71和10.79 ml·min-1(1.73m2)-1]均低于体表面积标准化Cockcroft-Gault方程的偏差[-7.18 ml·min-1·(1.73m2)-1]和平均绝对偏差[12.95 ml·min-1·(1.73 m2)-1].3个方程偏离测量值分别为21%、21%和22.5%,Cockcroft-Gault方程的偏离程度最大;计算值落在测量值±15%,±30%和±50%范围内的病例百分数分别为39.2%、39.7%和36.18%,72.36%、70.85%和63.82%,94.47%、92.45%和90.45%.结论MDRD方程7、简化MDRD方程和Cockcroft-Gault方程的GFR计算值均显著低于99mTc-DTPA血浆清除率,但MDRD方程7和简化MDRD方程偏离测量值程度低于体表面积标准化的Cockcroft-Gault方程.MDRD方程应用于我国,需按照我国人群特征将MDRD方程中的常量进行适当调整.     

六种肾小球滤过率估算方程对梗阻性肾病患者肾小球滤过率的比较

目的:比较六种肾小球滤过率估算方程在评价中国梗阻性肾病患者肾小球滤过率(Glomerular filtration rate,GFR)的适用性,即3种MDRD(Modification of Diet in Renal Disease,MDRD)公式和3种CKD-EPI(Chronic Kidney Disease Epidemiology Collaboration,CKD-EPI)公式。方法:选择2012年01月~2016年12月在我院完成99 m Tc-DTPA肾动态显像(ECT)检查的梗阻性肾病患者476例,以ECT所测得的GFR(m GFR)作为参考标准,用目前常用以上6种方程估算GFR(e GFR)为对照,分析各e GFR与m GFR的相关性,并就6种e GFR的估测偏差、精确度、准确率及诊断准确性进行比较。结果:本研究结果表明各e GFR与m GFR均显示高度的相关性(P0.01)。在数值诊断上,各e GFR与CKD-EPI联合方程e GFR间的估测偏差、精确度、15%、30%及50%范围的准确度比较差异有统计学意义(P0.05)。CKD-EPI方程较MDRD方程显示出较好的数值准确度,CKD-EPI联合方程所估算的GFR在数值上准确度最高。在诊断方面,3种CKD-EPI方程的ROC曲线下面积、分期诊断准确度及其一致性比3种MDRD方程更好,其中,CKD-EPI联合方程ROC曲线下面积最大(0.886),分期诊断准确度最高(44.1%),Kappa值最大(0.254,CI[0.179,0.311])。在亚组分析中,不同的亚组最适方程有所差别,其中简化MDRD与CKD-EPI联合方程在不同亚组中的适用性较高。结论:CKD-EPI方程对中国的梗阻性肾病患者较MDRD方程有更高的适用性,其中CKD-EPI联合方程所估算的e GFR值与m GFR值相关性最好,准确度最高,偏倚最小,诊断性能最好。     

Cystatin C相关方程在计算慢性肾脏病肾小球滤过率的对照研究

目的 评价血清半胱氨酸蛋白酶抑制剂C（Cystatin C，CysC）相关方程在不同病因引起慢性肾脏病（CKD）患者的肾小球滤过率（GFR）计算中的临床应用价值。方法选择CKD患者255例，运用MDRD方程（mGFR）、MDRD简化方程（rnGFR）、Hoek方程（hGFR）、2006年中华医学会肾脏病学分会推荐的方程（c-cGFR1，c-cGFR2）计算GFR，与^99m-二乙撑三胺五乙酸（^99m TcDT-PA）肾动态显像测得的。肾小球滤过率（sGFR）进行比较。结果在分期比较中，各方程估算的GFR和sGFR相关性一般，CysC相关方程能更敏感反应GFR；在不同病因分组中，各方程估算的GFR和sGFR均明显相关，特别是c-cGFR2。结论在CysC相关方程中，以2006中华公式2计算的c-cG-FR2与sGFR相关性及一致性最好，并且在糖尿病肾脏病组中，各方程相关系数优于其他组别，有必要进一步大规模临床研究证明其应用价值。     

三种肾小球滤过率检测方法的实用性探讨

目的：以^99mTc—DPTA血浆清除率为标准，对24h内生肌酐清除率（Ccr）、Cookeroft—Gault（CG）方程和简化MDRD（modification of diet in renal disease）方程进行比较，评价三种方程在慢性肾脏疾病（CKD）患者中的应用。方法：选择139例各种慢性肾脏疾病患者，将Ccr、CG方程和简化MDRM方程估算的肾小球滤过率（GFR）用体表面积（BSA）标准化，与BSA标准化的^99mTc—DTPA测得的GFR（^99mTc—GFR）在不同CKD分期进行比较。结果：CKD第一至第五期：Ccr与^99mTc—GFR相关系数r分别为：0．79、0．71、0．64、0．59、0．52；Ccr在ROC曲线下面积平均为0．79。CG—GFR与^99mTc—GFR相关系数r分别为：0．85、0．78、0．72、0．67、0．61；CG—GFR在ROC曲线下面积平均为0．83。MDRD—GFR与^99mTc—GFR相关系数r分别为：0．83、0．76、0．69、0．65、0．59；MDRD—GFR在ROC曲线下面积平均为0．82。在CKD不同分期三种方程的GFR估算值与^99mTc—GFR差异均有显著意义（P均〈0．001）。结论：三种方程的GFR估算值与^99mTc—GFR均有较好的相关性和ROC曲线下面积，以CG方程最好，其次为简化MDRD方程，Ccr最低，但三种方程估算值与^99mTc—GFR测定值差异均有显著意义。上述方程直接应用于我国CKD患者时，应对其进行适当修正。     

亲属活体肾移植供者的安全性分析

目的 分析亲属活体肾移植供者手术前后的相关指标变化,探讨活体供者的安全性.方法对132例亲属活体供肾者进行心理和生理分析,包括尿常规、血生化、肾小球滤过率(GFR)、内生肌酐清除率(CCr)和生活质量等指标.结果 132例供肾者的生活质量评分与正常人群比较差异无统计学意义(P＞0.05).供肾切取术前供者血肌酐(SCr)为(78.33±15.94)μmol/L,术后7 d为(108.49±19.88)μmol/L(P=0.000);术后6个月为(112.47±20.38)μmol/L,与术后7 d比较差异无统计学意义(P=0.109).供肾切取术前供者CCr为(95.80±20.92)ml/min,术后7 d为(57.36±14.92)ml/min,与术前比较P=0.017;术后6个月为(65.49±8.25)ml/min,与术后7 d比较差异无统计学意义(P=0.619).术前双肾GFR为(74.08±18.51)ml/min,右肾GFR为(38.43±10.33)ml/min,供肾切取术后6个月保留右肾GFR为(56.49±13.01)ml/min,与术前双肾GFR比较,P=0.000;保留右肾GFR与术前自身比较代偿性增加47.0%.手术并发症包括脾脏包膜下出血1例,降结肠破裂1例,切口脂肪液化5例. 结论 术前对供肾者进行充分系统的医学心理学和生理学评估,严格履行风险告知义务,供受者术中规范操作,围手术期合理管理和建立严密的随访制度,可以有效提高亲属活体移植供肾者的心理和生理安全性.     

修正Gates’法测定肾小球滤过率的初步研究

目的拟合新的肾小球滤过率(GFR)估算公式并验证,从而探讨对Gates’法测定GFR进行修正的可行性。方法收集2011年9月至2016年3月于中山大学附属第三医院就诊的慢性肾脏病(CKD)成人患者资料,符合入选标准病例共229例,以双血浆法测定出GFR(记为rGFR),应用传统Gates’方程计算GFR(记为gGFR),以rGFR为标准将CKD患者按全球肾脏病预后组织(KDIGO)指南分期,将全部病例行分层(按期别)随机抽样分为A、B两组。以A组患者应用肾动态显像得出的双肾放射性摄取率为自变量,以rGFR为因变量行回归分析,拟合出最优曲线,得出新的GFR估算公式。将新公式应用于B组数据,得出新的GFR与rGFR行配对t检验,并运用Spearman秩相关分析,Bland-Altman一致性检验及准确性比较。结果经新拟合方程计算的GFR(线性拟合记为GFRl,曲线拟合记为GFRc)及gGFR均与rGFR密切相关(P0.01)。GFRl、GFRc与rGFR相关性高于gGFR(r=0.885)。GFRc与rGFR的一致性最好,一致性界限范围最小(-27.8,29.6),偏离度最低[偏差和绝对偏差分别为-0.90、11.64 ml·(min·1.73 m~2)~(-1)]。GFRl次之。Gates’法gGFR与rGFR的一致性最差,一致性界限范围超过事先规定的专业界值60 ml·(min·1.73 m~2)~(-1)。准确性比较,GFRl、GFRc及gGFR的±30%病例符合率分别为75.2%、73.5%、62.8%,gGFR与GFRl、GFRc比较差异具有统计学意义(P0.01)。结论新拟合方程计算的GFR与双血浆法GFR具有较好的相关性和一致性,其准确性优于Gates'方程,对Gates'方程能够起到一定的修正作用。三次拟合方程评估GFR的一致性及准确度最佳。     

Assessing glomerular filtration rate in healthy Indian adults: a comparison of various prediction equations

BACKGROUND: Accurate measurement of renal function is important for the diagnosis, stratification and management of kidney disease. As the use of recommended filtration markers is limited by cumbersome and costly techniques, renal function is typically estimated by using various specifically derived prediction equations. Most of these equations have been derived from Caucasian patients suffering from varying degrees of chronic kidney disease. This study considers the validity of these equations in an Indian population without known kidney disease. METHODS: One hundred and twenty-two consecutive renal donors who had undergone 99mTc-diethylenetriaminepentaaceticacid (DTPA) glomerular filtration rate (GFR) estimation were enrolled. The predictive capabilities of the Cockcroft and Gault equation for creatinine clearance corrected for body surface area (CG-CrCl), CG-CrCl corrected for GFR (CG-GFR), modification of diet in renal disease (MDRD) 1, MDRD 2 and 24-hr urinary creatinine clearance (urine-CrCl) were evaluated with DTPA GFR as measured GFR. RESULTS: The mean age of the study population was 44.7 yrs with 72.2% being female). The mean measured DTPA GFR was 83.42 ml/min with a range of 61-130 ml/min. The median % absolute difference between the calculated and measured GFR was 19.7, 15.4, 19.3, 20.8 and 25.5, respectively, for CG-CrCl, CG-GFR, MDRD 1, MDRD 2 and urine-CrCl. Pearson's correlation between the measured and estimated GFR varied from 0.09-0.27. The precision as reflected by R2 value was 0.05 for CG-CrCl and CG-GFR, 0.06 for MDRD 1 and MDRD 2 and 0.01 for urine-CrCl. The bias was -14.14, 1.46, 11.89, 17.70 and -2.80 for CG-CrCl, CG-GFR, MDRD 1, MDRD 2 and urine-CrCl, respectively. The accuracy within 30% was 71.3, 85, 86, 76 and 69% for CG-CrCl, CG-GFR, MDRD 1, MDRD 2 and urine-CrCl, respectively. CONCLUSIONS: Our results from a healthy Indian population suggest that of all the predictive equations, MDRD 1 and MDRD 2 were the most precise, MDRD 1 the most accurate and CG-GFR the least biased. However, the poor correlation and error level exhibited by these equations makes them sub-optimal for clinical use.     

A comparison of prediction equations for estimating glomerular filtration rate in adults without kidney disease

The ability of the Modification of Renal Disease (MDRD) equation to predict GFR when compared with multiple other prediction equations in healthy subjects without known kidney disease was analyzed. Between May 1995 and December 2001, a total of 117 healthy individuals underwent (125)I-iothalamate or (99m)Tc-diethylenetriamine-pentaacetic acid (DTPA) renal studies as part of a routine kidney donor evaluation at either Brigham and Women's Hospital or Boston Children's Hospital. On chart review, 100 individuals had sufficient data for analysis. The MDRD 1, MDRD 2 (simplified MDRD equation), Cockcroft-Gault (CG), Cockcroft-Gault corrected for GFR (CG-GFR), and other equations were tested. The median absolute difference in ml/min per 1.73 m(2) between calculated and measured GFR was 28.7 for MDRD 1, 18.5 for MDRD 2, 33.1 for CG, and 28.6 for CG-GFR in the (125)I-iothalamate group and was 31.1 for MDRD 1, 38.2 for MDRD 2, 22.0 for CG, and 31.1 for CG-GFR in the (99m)Tc-DTPA group. Bias was -0.5, -3.3, 25.6, and 5.0 for MDRD 1, MDRD 2, CG, and CG-GFR, respectively, in subjects who received (125)I-iothalamate and -33.2, -36.5, 6.0, and -15.0 for MDRD 1, MDRD 2, CG, and CG-GFR, respectively, in those who received (99m)Tc-DTPA studies. Precision testing, as measured by linear regression, yielded R(2) values of 0.04 for CG, 0.05 for CG-GFR, 0.15 for MDRD 1, and 0.14 for MDRD in those who underwent (125)I-iothalamate studies and 0.18 for CG, 0.21 for CG-GFR, 0.40 for MDRD 1, and 0.38 for MDRD 2 for those who underwent (99m)Tc-DTPA studies. The MDRD equations were more accurate within 30 and 50% of the measured GFR compared with the CG and CG-GFR equations. When compared with the CG equation, the MDRD equations are more precise and more accurate for predicting GFR in healthy adults. The MDRD equations, however, consistently underestimate GFR, whereas the CG equations consistently overestimate measured GFR in people with normal renal function. In potential kidney donors, prediction equations may not be sufficient for estimating GFR; radioisotope studies may be needed for a better assessment of GFR. Further studies are needed to derive and assess GFR prediction equations in people with normal or mildly impaired renal function.     

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.     

A comparison of prediction equations for estimating glomerular filtration rate in Chinese potential living kidney donors

Abstract: Background: Accurate measurement of donor renal function has important long‐term implications for both donors and recipients. In clinical practice, renal function may be estimated by using 24‐h urinary creatinine clearance (urine‐CrCl) and various specifically derived prediction equations. We assessed the suitability of urine‐CrCl and prediction equations for evaluating Chinese kidney donors. Methods: A total of 224 donors who had undergone ^99mTc‐diethylenetriaminepentaacetic acid glomerular filtration rate (GFR) estimation were enrolled. We evaluated the performance of the Cockcroft–Gault equation (CG‐CrCl), the CG‐CrCl equation corrected for GFR (CG‐GFR), the isotope dilution mass spectrometry traceable modification of diet in renal disease (IDMS‐MDRD) study equation, the new MDRD study equation for Chinese (C‐MDRD 1), the modified MDRD study equation with a Chinese coefficient (C‐MDRD 2), the modified IDMS‐MDRD study equation with a Japanese coefficient (J‐MDRD), and urine‐CrCl in predicting GFR before donation. Results: Of 224 donors selected, 68 were male and 156 were female. Of all the prediction equations, C‐MDRD 1 was the least scattered and most precise. However, predictive performance was poor for all the equations. Conclusion: The performance of urine‐CrCl and all the equations was disappointing, and even the best performing equation C‐MDRD 1 was unacceptable. Considering the potential risk of living kidney donation, other more accurate methods of GFR measurement should be used in clinical practice.     

Creatinine-based equations predicting chronic kidney disease after kidney donation

Background

Kidney donation is associated with few adverse outcomes in living donors. The aim of this study was to evaluate the outcomes of living kidney donors and the utility of creatinine-based equations to predict chronic kidney disease.

Methods

The study population was selected among 154 living kidney donors from 2001 to 2009. Seventy-eight patients underwent medical consultation to review demographic data and perform laboratory evaluations. Estimated glomerular filtration rate (GFR) values were obtained by three equations: Modification of Diet in Renal Disease (MDRD), Cockcroft-Gault (C-G) and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI). Receiver operating characteristic (ROC) analysis was performed to determine the area under the curve of each equation to predict evolution to chronic kidney disease.

Results

The overall median age was 39 years including 64% of women subjects. The mean follow-up after kidney donation was 65 ± 34 months. During follow-up, 20.5% of patients developed hypertension. Serum creatinine values above 1.5 mg/dL were detected in 14.1% of cases. Dyslipidemia was present in 33.3% of donors at the last follow-up. According to measured creatinine clearance and the C-G equation, only four and six donors had renal failure (defined as GFR < 60 mL/min), a number that increased to 23 (29.4%) when considering the MDRD or CKD-EPI equations (P < .05). ROC curves performed to explore the GFR measurements to predict renal failure occurrence after donation showed the CKD-EPI to be the only one with a significant area under the curve (0.7442, P = .003).

Conclusion

Living kidney donors should receive careful long-term follow-up. Assessment of renal function before donation using CKD-EPI creatinine-based equations must be performed preferentially. A careful approach should be adopted for the detection and treatment of other complications such as hypertension and dyslipidemia.     

Predicting Glomerular Filtration Rate in Kidney Transplantation: Are the K/DOQI Guidelines Applicable?

The kidney disease outcomes quality initiative (K/DOQI) guidelines introduced a classification of chronic kidney disease (CKD) based on the level of kidney function. In order to predict the glomerular filtration rate (GFR), they specifically recommended the use of the modification of diet in renal disease (MDRD) study and Cockcroft-Gault (C-G) equations. Since the performance of these estimates has been questioned, we sought to determine whether these recommendations might be applicable in renal transplantation. Following the K/DOQI methodology, we compared the GFR estimated by the MDRD and C-G equations with 476 inulin clearances performed in 284 renal transplant recipients. Even though the MDRD equations provided a better prediction than C-G formula, none of them reached the level of accuracy required by the K/DOQI standards. At least, 25% of the calculated GFR gave a prediction beyond 30% of the corresponding inulin clearance value. In addition, when classified according to their predicted GFR, less than two-thirds of the transplant patients turned out to be assigned to the correct stage of CKD. We conclude that, in renal transplantation, the predictive performance of both C-G and MDRD study equations appears to be particularly impaired and may potentially compromise the validity of the K/DOQI guidelines if implemented in their current form.     

Is Cyctatin C Valuable Marker of Glomerular Filtration Rate in Living Kidney Donors After Uninephrectomy?

BackgroundThe determination of kidney function plays a pivotal role in living donors renal assessment because of the long-term hazards of life with one kidney. Guidelines recommend estimation of glomerular filtration rate (GFR) by the Modification of Renal Disease (MDRD) or Cockroft-Gault equations for people with normal or near-normal renal function. Cystatin C (CysC) has been introduced as an alternative endogenous marker of GFR.ObjectiveThe objective of the study was to evaluate residual renal function among living kidney donors by comparing serum CysC concentrations and estimated GFR according to the MDRD formula or the Cockroft-Gault equation.Patients and methodsForty living kidney donors showed a mean age of 46.14 years. Their GFR was estimated according to the abbreviated MDRD (aMDRD) and Cockroft-Gault formula adjusted for body surface area. Twenty-two donors underwent diethylenetriaminepentaacetic acid (DTPA) renal studies. Serum CysC concentrations were measured during the last follow-up visit. GFR values according to Cockroft-Gault formula and MDRD formula were correlated with CysC concentrations using Pearson's linear correlation.ResultsMean GFR according to the aMDRD formula and Cocroft-Gault formula decreased after nephrectomy. The Cockroft-Gault formula overestimated the DTPA GFR in our study. No significant differences were observed between DTPA GFR and GFR estimated using the aMDRD equation. The rate of GFR decrease was approximately 0.8 mL/min/1.73m² per year. No significant correlation was observed between serum CysC concentration and GFR. Microalbuminuria was observed in one patient after nephrectomy.ConclusionsaMDRD equation to estimate GFR is more precise than Cockroft-Gault formula and cystatin C in living kidney donors after nephrectomy and should be preferred model in these patients.