Chronic Kidney Disease Epidemiology Equation Research Articles

Balancing the scales: achieving the optimal beta-lactam to beta-lactamase inhibitor ratio with continuous infusion piperacillin/tazobactam against extended spectrum beta-lactamase producing Enterobacterales.

Piperacillin/tazobactam (TZP) is administered intravenously in a fixed ratio (8:1) with the potential for inadequate tazobactam exposure to ensure piperacillin activity against Enterobacterales. Adult patients receiving continuous infusion (CI) of TZP and therapeutic drug monitoring (TDM) of both agents were evaluated. Demographic variables and other pertinent laboratory data were collected retrospectively. A population pharmacokinetic approach was used to select the best kidney function model predictive of TZP clearance (CL). The probability of target attainment (PTA), cumulative fraction of response (CFR) and the ratio between piperacillin and tazobactam were computed to identify optimal dosage regimens by continuous infusion across kidney function. This study included 257 critically ill patients (79.3% male) with intra-abdominal, bloodstream, and hospital-acquired pneumonia infections in 89.5% as the primary indication. The median (min-max range) age, body weight, and estimated glomerular filtration rate (eGFR) were 66 (23-93) years, 75 (39-310) kg, and 79.2 (6.4-234) mL/min, respectively. Doses of up to 22.5 g/day were used to optimize TZP based on TDM. The 2021 chronic kidney disease epidemiology equation in mL/min best modeled TZP CL. The ratio of piperacillin:tazobactam increased from 6:1 to 10:1 between an eGFR of <20 mL/min and >120 mL/min. At conventional doses, the PTA is below 90% when eGFR is ≥100 mL/min. Daily doses of 18 g/day and 22.5 g/day by CI are expected to achieve a >80% CFR when eGFR is 100-120 mL/min and >120-160 mL/min, respectively. Inadequate piperacillin and tazobactam exposure is likely in patients with eGFR ≥ 100 mL/min. Dose regimen adjustments informed by TDM should be evaluated in this specific population.

Performance of Future Glomerular Filtration Rate Equation by Race in a Large, Racially Diverse Patient Cohort Undergoing Nephrectomy for Renal Cell Carcinoma

ObjectiveTo examine the performance of the Palacios et al. (2021) post-nephrectomy future glomerular function rate (fGFR) equation in a diverse cohort using both the Chronic Kidney Disease Epidemiology (CKD-EPI) 2009 equation with race, used in the creation of the formula, as well as the CKD-EPI 2021 equation without race. MethodsPatients that underwent partial or radical nephrectomy for renal cell carcinoma from 2005-2021 were identified in our institutional database. Patients with creatinine values preoperatively and 3-12 months postoperatively were included. Correlation/bias/accuracy/precision of the fGFR equation (fGFR=35+ [preoperative eGFR x 0.65]- 18 [if radical] - [age x 0.25]+ 3 [if tumor >7cm]-2 [if diabetes]) with observed postoperative eGFR was determined by both the CKD-EPI-2021 and CKD-EPI 2009 equations. Results1,443 patients were analyzed. 71% (1,024) were white and 22.9% (331) were black. Most underwent radical nephrectomy (60.3%). 40% T3-T4 RCC, with 14.8% of patients having M1 disease. Median observed vs predicted fGFR was 58.0 vs 58.7 ml/min/1.73m2 for CKD-EPI 2021 and 56.0 vs 57.5 for CKD-EPI 2009. For the total cohort, the correlation/bias/accuracy/precision of the fGFR equation was 0.805/-0.5/81.7/7.9-9.0 for CKD-EPI 2021 and 0.809/-0.8/81.3/-8.1-8 for CKD-EPI 2009. In black patients, fGFR equation demonstrated >75% accuracy with both CKD-EPI equations; however, accuracy was lower in black patients with the CKD-EPI2021 equation (76.1% vs. 83.4%, p=0.003). ConclusionsThe fGFR equation performed well in our large, diverse cohort, though accuracy was relatively lower when using CKD-EPI 2021 compared to CKD-EPI 2009.

Correlation of eGFR values estimated by different equations based on creatinine and cystatin-C in patients on hemodialysis treatment at Teaching Hospital Karapitiya, Galle, Sri Lanka

The present study was to compare eGFR values estimated from different equations based on creatinine and cystatin-C in patients on hemodialysis treatment. eGFR values were calculated using Modification of Diet in Renal Disease (MDRD), Chronic Kidney Disease Epidemiology equations based on Creatinine (CKD-EPICr) and cystatin-C values alone (CKDEPI Cys C) and by their combination (CKD-EPICr-Cys C), using 40 pre-dialysis samples. No significant differences in renal function parameters and eGFR were observed, either between male (55%) and female (45%) patients or within different age groups (p&gt;0.05). Certain levels of agreement (p&gt;0.05) were observed between the equations, except for the values derived from CKD-EPICys C and CKD-EPICr-Cys C (p = 0.022). Significant positive correlations were observed between all selected equations. The highest correlation was observed between CKD-EPICr and MDRD (r = 0.998, p = 0.000), whereas the lowest correlation was found between MDRD and CKD-EPICys C (r = 0.552, p = 0.000). The present findings revealed that MDRD and CKD-EPICr equations are suitable for the calculation of eGFR in routine local clinical settings for the assessment of progression of kidney impairment in patients with CKD on hemodialysis treatment. However, the use of CKD-EPICr-Cys C rather than the CKD-EPICys C is recommended as a confirmatory tool where necessary.

The New 2021 CKD-EPI Equation Without Race in a European Cohort of Renal Transplanted Patients.

Whether the new chronic kidney disease-epidemiology (CKD-EPI) equation without the race variable remains accurate enough for glomerular filtration rate (GFR) estimation in non-US kidney transplant recipients (KTRs) is unclear. We sought to compare the predictive performance between this equation and the classical CKD-EPI equation in a French cohort of KTRs. We also evaluated the performance of the European Kidney Function Consortium (EKFC) equation, an estimate that has proved very accurate in nontransplant patients and that does not include race variable. We retrospectively selected 489 KTRs for whom GFR was measured by inulin clearance. Performances of GFR equations were compared according to median bias, imprecision, and accuracy within 30% (P30) and 20% (P20). Differences in P20/P30 were tested using the exact McNemar test. Although the 4 equations exhibited a similar level of imprecision, the bias of the new CKD-EPI equation was +5.5 (4.0; 6.6) mL/min/1.73 m², much higher than the bias of the classical CKD-EPI, EKFC, and Modified Diet in Renal Diseases (MDRD) equation (2.4 [1.7;3.5], 2.2 [1.1;3.1], and -0.5 [-1.5; 1.0] mL/min/1.73 m², respectively). The new CKD-EPI equation was significantly less accurate with a P30 of 68.3% as compared with 74.2%, 75.3%, and 77.1% for the classical CKD-EPI, EKFC, and MDRD equation, respectively. The EKFC equation outperformed both versions of the CKD-EPI equation in terms of P20. The new CKD-EPI equation is suboptimal for the care and follow-up of European transplanted patients. The EKFC equation shows at least a similar performance to the MDRD and the classical CKD-EPI equation. Further validation of the EKFC equation in KTRs from a diverse ethnic background is needed.

Glomerular Filtration Rate Estimation With Commonly Used Methods Among Healthy Live Kidney Donors of South Punjab, Pakistan.

BackgroundAccurate estimation of the donor’s glomerular filtration rate (GFR) is crucial for not only ensuring the medical appropriateness of the donor but also for the prediction of future allograft performance. The aim of this study was to compare the GFR estimation formulas and 24-hour urine creatinine clearance with diethylene triamine pentaacetic acid (DTPA) renal scan GFR.MethodsThis cross-sectional study was done at the Department of Nephro Urology Dialysis & Renal Transplantation, Bahawal Victoria Hospital, Quaid e Azam Medical College, Bahawalpur, Pakistan from September 2018 to September 2021. A total of 92 potential healthy live-related kidney donors of both genders, aged 18 to 60 years having body mass index below 35 kg/m2 were included. GFR was calculated with modification of diet in renal disease (MDRD), Cockcroft-Gault (CG), chronic kidney disease epidemiology (CKD-EPI) equations as well as by 24-hour urine creatinine clearance. DTPA renal scan was done to record GFR findings. GFR was compared using analysis of variance (ANOVA) among different methods.ResultsOut of a total of 92 individuals, 49 (53.3%) were male and 43 (46.7%) female. Mean age and BMI were noted to be 34.62±10.57 years and 24.40±2.71 kg/m2, respectively. Statistically significant differences existed between various methods of GFR estimation (p<0.001). Mean GFR as per DTPA renal scan findings was noted to be 97.32±9.39 ml/min/1.73 m2. Difference of 31.48±20.81, 27.37±21.1, 23.38±6.38, 15.52±37.52 was noted in estimated GFR (ml/min/1.73 m2) with CG formula, MDRD formula, EPI-CKD formula and 24-hour urine creatinine clearance respectively when compared with DTPA renal scan findings. The highest proportion of patients was seen with normal GFR with DTPA renal scan findings as 83 (90.2%) individuals while 24-hour urine creatinine clearance observed these to be 59 (64.1%), CG EPI-CKD formula 44 (47.8%), MDRD formula 39 (42.4%) and 40 (43.5%) with CG formula.ConclusionNone of the GFR estimation methods resulted in similar findings. With reference to the DTPA renal scan, 24-hour urine creatinine clearance was the closest GFR estimation followed by CKD-EPI and MDRD equations.

The « race » correction in estimating glomerular filtration rate: an European point of view.

There is currently a heated debate ongoing whether or not to use the race coefficient for black people in the Modification of Diet in Renal Diseases and Chronic Kidney Disease Epidemiology-equation. The use of the race coefficient is thought by several American authors as a source of discrimination. It has recently been shown that the race coefficient is inaccurate in European and African black people. Therefore, it seems that the race correction is more a correction for black Americans, rather than for black in general. This 'correction' at the glomerular filtration rate (GFR)-level has been criticized, as it is misleading, and should be abandoned, as it has not been shown that GFR is different between black and white people. However, as differences in creatinine generation between black and white people might exist, a correction or adjustment, different for black and white people, at the creatinine level might be required, very similar to the different scaling of creatinine for males and females. The current debate on the race coefficient is particularly difficult because of the absence of good scientific data in black subjects and there lies the real discrimination in our opinion. We therefore call for future dedicated studies, both in Europe and USA.

Analysis of Estimated and Measured Glomerular Filtration Rates and the CKD-EPI Equation Race Coefficient in the Chronic Renal Insufficiency Cohort Study

This diagnostic/prognostic study examines the estimated glomerular filtration rates (eGFR) and iothalamate clearance glomerular filtration rates (iGFR) and the Chronic Kidney Disease-Epidemiology (CKD-EPI) equation race coefficient in the Chronic Renal Insufficiency Cohort study.

Meropenem Pharmacokinetics and Target Attainment in Critically Ill Patients Are Not Affected by Extracorporeal Membrane Oxygenation: A Matched Cohort Analysis.

Existing evidence is inconclusive whether meropenem dosing should be adjusted in patients receiving extracorporeal membrane oxygenation (ECMO). Therefore, the aim of this observational matched cohort study was to evaluate the effect of ECMO on pharmacokinetic (PK) variability and target attainment (TA) of meropenem. Patients admitted to the intensive care unit (ICU) simultaneously treated with meropenem and ECMO were eligible. Patients were matched 1:1, based on renal function and body weight, with non-ECMO ICU patients. Meropenem blood sampling was performed over one or two dosing intervals. Population PK modelling was performed using NONMEM7.5. TA was defined as free meropenem concentrations >2 or 8 mg/L (i.e., 1 or 4× minimal inhibitory concentration, respectively) throughout the whole dosing interval. In total, 25 patients were included, contributing 27 dosing intervals. The overall TA was 56% and 26% for the 2 mg/L and 8 mg/L target, respectively. Population PK modelling identified estimated glomerular filtration rate according to the Chronic Kidney Disease Epidemiology equation and body weight, but not ECMO, as significant predictors. In conclusion, TA of meropenem was confirmed to be poor under standard dosing in critically ill patients but was not found to be influenced by ECMO. Future studies should focus on applying dose optimisation strategies for meropenem based on renal function, regardless of ECMO.

Chronic Kidney Disease and Associated Factors Among HIV Infected Patients Taking Tenofovir Disoproxil Fumarate Based Regimen in Ethiopia: A Hospital-Based Cross-Sectional Study.

BackgroundLife expectancy of HIV patients has increased by the extensive use of antiretroviral therapies (ART), but ART predisposes patients to chronic non-communicable diseases including chronic kidney disease (CKD). Tenofovir disoproxil fumarate is one of the commonly used drugs in ART and is found to have more risk for developing CKD. In the study areas, there was no previous study addressing the prevalence of CKD, so the purpose of this study was to pinpoint the prevalence of CKD, and its associated factors.MethodsA hospital-based cross-sectional study was employed at Tikur Anbessa Specialized Hospital (TASH) and Zewuditu Memorial Hospital (ZMH) from April 1 to June 30, 2019. The study participants were proportionally allocated to each hospital and a total of 243 eligible participants were selected conveniently from the two hospitals in the study period. Structured questionnaire and checklist were used to collect socio-demographic and clinical data of the participants. Blood samples (3–5 ml) were used to determine serum creatinine using calibrated fully automated Mind ray BS-200E, and glomerular filtration rate (GFR) was estimated using a chronic kidney disease epidemiology equation. Multivariate logistic regression was employed to identify factors associated with CKD, and a P-value of less than 0.05 was considered significant.ResultsIn the present study, the prevalence of CKD (GFR <60 ml/min/1.73 m2) was 4.53% (95% CI = 2.3–8%). GFR was classified into stages, stage 5 (GFR <15), stage 4 (15–29.9), stage 3 (30–59.9), stage 2 (60–89.9), and stage 1 (≥90) were 0%, 0.4%, 4.1%, 38.3%, and 57.2%, respectively. In the multivariate logistic regression, age greater than 50 years old, and having cancer were significantly associated with CKD (AOR: 0.22, 95% CI = 0.05–0.88, P = 0.033, and AOR: 18.20, 95% CI = 122–271.77, P = 0.035, respectively).ConclusionChronic kidney disease in HIV-infected patients receiving a TDF-based regimen requires attention. Age >50 years old, and having cancer as comorbidity were significantly associated with chronic kidney disease. Patients should be regularly monitored for early diagnosis and management of chronic kidney disease in a TDF-based regimen.

Renal function as a predictor of outcomes in patients with hypertrophic cardiomyopathy: A cohort study of a hospitalized population

BackgroundThe relationship between renal function and outcomes among patients with hypertrophic cardiomyopathy (HCM) remains undefined. We sought to investigate the prevalence of renal dysfunction and its prognostic value in HCM patients. MethodsA total of 581 patients with HCM were consecutively recruited. The chronic kidney disease epidemiology equation was used to estimate the glomerular filtration rate (eGFR). Patients were divided into 2 eGFR categories: ≥60 or <60 ml/min/1.73 m2. The predictive value of renal function was assessed using Cox regression. ResultsThe proportions of eGFR 60–90 ml/min/1.73 m2 and <60 ml/min/1.73 m2 were 41.8% and 15.3%, respectively. Estimated GFR independently predicted the risk of all-cause mortality [HR 0.98, 95% confidence interval (CI) 0.96–0.99, P < 0.001]. Compared to those with eGFR ≥ 60 ml/min/1.73 m2, patients with eGFR < 60 ml/min/1.73 m2 were independently associated with all-cause mortality (HR, 3.42 95% CI 1.86–6.28), cardiovascular mortality (HR 2.98, 95% CI 1.36–6.50) and combined adverse outcomes (HR 1.60, 95% CI 1.02–2.49). HRs for all-cause mortality with renal dysfunction were attenuated in patients with older ages (P for interaction = 0.034). ConclusionsRenal dysfunction is a common comorbidity in HCM. Renal function is an independent predictor of outcomes in patients with HCM. These findings highlight the clinical importance of renal dysfunction in HCM.

Clearance Confusion: An Exploratory Analysis of Inpatient Dosing Discordances Between Renal Estimating Equations.

Numerous equations exist for estimating renal clearance for drug dosing, and discordance rates may be as high as 40% in certain populations. However, the populations and types of equations used in these studies may not be generalizable to broader pharmacy practice. To determine the dosing discordance rate between Cockcroft-Gault (C-G), Chronic Kidney Disease Epidemiology (CKD-EPI), and Modification of Diet in Renal Disease (MDRD) equations in a community hospital population. This was a cross-sectional analysis of inpatients who had documented renal function assessment over a 6-month period. Renal estimation was calculated using 5 equations (MDRD, CKD-EPI, and 3 C-G variants). Differences between equations were assessed using mean bias, dosing discordance, and agreement (κ statistic). Patients with acute kidney injury and those requiring renal replacement therapy were excluded. A total of 466 patients were eligible for inclusion. Dosing discordance was evident between C-G variants and both MDRD and CKD-EPI equations in greater than 20% of patients. Agreement was highest between MDRD and CKD-EPI (κ = 0.93) and lowest between MDRD and C-G calculated using ideal body weight (κ = 0.33). The majority of discordant instances led to higher dosing recommendations when using MDRD and CKD-EPI equations compared with C-G variants. Dosing discordance exceeded 18% between the different C-G variants, with the highest discordance (36%) observed between total body weight and ideal body weight variants. Dosing discordance between renal estimating equations is widespread. Practitioners and institutions should be aware of these differences when dosing medications and implementing renal dosing policies.

Prevalence of Chronic Kidney Disease and Associated Factors among Patients with Diabetes in Northwest Ethiopia: A Hospital-Based Cross-Sectional Study

BackgroundChronic kidney disease (CKD) is increasingly recognized as a global health issue and it affects 10% to 15% of the world population. Diabetes mellitus is the leading cause of end-stage renal disease. More than 422 million adults in the world populations are living with diabetes mellitus, 40% of whom will develop CKD. CKD in diabetes increases the risk of early death and cardiovascular morbidity and mortality. There is a paucity of published data on the prevalence of CKD and its associated factors among patients with diabetes in northwest Ethiopia.ObjectiveThe aim of this study is to determine the prevalence and factors associated with CKD among patients with diabetes at University of Gondar Hospital, Northwest Ethiopia.MethodsA hospital-based cross-sectional study was conducted from April 2 to July 31, 2018. Using convenience sampling, a total of 272 consecutive patients with diabetes were recruited for the study. Data regarding the patients’ sociodemographic information, clinical characteristics, and laboratory parameters were collected using patient interview and review of medical records. Serum creatinine was measured and used to calculate estimated glomerular filtration rate using modification of diet in renal disease and chronic kidney disease epidemiology equations. Data were analyzed using SPSS version 20. Bivariate and multivariate logistic regression analyses were used to identify predictors of CKD in patients with diabetes.ResultThe prevalence of CKD, defined by estimated glomerular filtration rate <60 mL/min/1.73 m2, was found to be 17.3% and 14.3% by modification of diet in renal disease and chronic kidney disease epidemiology equations, respectively. The proportion of stage 3 CKD by modification of diet in renal disease equation was 14.7%, whereas the proportions of stage 4 and stage 5 CKD were 2.2% and 0.4%, respectively. Among those who were diagnosed with CKD, 85.1% had pre-existing hypertension. Multivariate logistic regression analysis revealed that the presence of retinopathy (adjusted odds ratio = 14; 95% CI, 4–36; p < 0.001), pre-existing hypertension (adjusted odds ratio = 8.2; 95% CI, 2–23; P < 0.001), current systolic blood pressure >140 mm Hg (adjusted odds ratio = 6; 95% CI, 4–22; P = 0.001), and duration of diabetes >10 years (adjusted odds ratio = 3.2; 95% CI, 2–7; P = 0.004) were significantly associated with CKD in patients with diabetes.ConclusionsThe prevalence of CKD in patients with diabetes is high and comparable with previous studies from low- and middle-income countries. Pre-existing hypertension, current systolic blood pressure >140 mm Hg, duration of diabetes >10 years, and presence of retinopathy were significantly associated with CKD. Regular screening for CKD, retinopathy, and optimal blood pressure management should be practiced.

Performance of creatinine- or cystatin C–based equations to estimate glomerular filtration rate in sub-Saharan African populations

Glomerular filtration rate (GFR) is the best index for kidney function; however, the applicability of GFR estimating equations in sub-Saharan African populations remains unclear. In a cross-sectional study of adults living in Kinshasa, Democratic Republic of Congo (n=210) and Abidjan, Ivory Coast (n=284), we evaluated the performance of creatinine and cystatin C-based equations using plasma clearance of iohexol as the reference standard. The race coefficient did not improve the performance of creatinine-based GFR estimates; in fact, both the Modification of Diet in Renal Disease (MDRD) and Chronic Kidney Disease Epidemiology (CKD-EPI) equations performed better without the race coefficient in participants with GFR≥60 mL/min/1.73m2. The CKD-EPI and Full Age Spectrum (FAS) equations were unbiased and had similar precision (SD of 17.9 versus 19 mL/min/1.73 m2) and accuracy within 30% (P30, 86.7% versus 87.4%) in participants with GFR≥60 mL/min/1.73m2. Both equations performed poorly in the subgroup with measured GFR< 60 mL/min/1.73m2 (n=80), but the FAS equation had smaller bias (-4.8 mL/min/1.73m2 versus-7.7 mL/min/1.73m2 for CKD-EPI) and higher P30 (56.3% versus 31.3% for CKD-EPI). The corresponding equations including cystatin C alone or in combination with creatinine had similar performance. In a sub-Saharan African population, adjustment for race did not improve the performance of GFR estimating equations. The creatinine-based FAS and CKD-EPI equations performed reasonably well and were comparable when GFR was≥ 60 mL/min/1.73m2. Cystatin C did not improve performance. The FAS equation may be preferable when GFR is< 60 mL/min/1.73m2, but this should be confirmed in larger studies.

Serum Creatinine and Chronic Kidney Disease-Epidemiology Estimated Glomerular Filtration Rate: Independent Predictors of Renal Replacement Therapy following Cardiac Surgery

Background: Most studies evaluating predictors of renal replacement therapy (RRT) following cardiac surgery use arbitrary defined limits of preoperative serum creatinine. The aim of this study was to evaluate the effect of preoperative renal function using either estimated-glomerular filtration rate (eGFR) derived using Chronic Kidney Disease-Epidemiology (CKD-EPI) or serum creatinine alone as a predictor for RRT after cardiac surgery. Methods: In this prospective cohort study, baseline, intraoperative, and postoperative data of all patients who underwent an elective, urgent, or emergency cardiac surgery between 2012 and 2016 in a single center were analyzed in order to identify multivariate parameters determining the need for RRT after surgery. For preoperative renal function, we used serum creatinine levels and eGFR-derived CKD-EPI equation. We also divided our cohort into eGFR groups following the thresholds of the currently proposed CKD classification. Results: From the 1,614 patients (mean age: 65.4 ± 10.6 years; male: 77.6%) that constituted the study population, 42 (2.6%) underwent RRT postoperatively. EUROSCORE II, cardiopulmonary bypass time, cross clamp time, red blood cell (RBC) units transfused, type and urgency of surgery, combined/non combined operation, peripheral vascular disease, heart failure, chronic obstructive pulmonary disease, dyslipidemia, and preoperative renal function were all univariately associated with RRT use. Multivariate regression with bootstrap utilization indicated that CKD-EPI eGFR (OR 0.979; 95% CI 0.956–0.998), heart failure with the New York Heart Association class ≥2 (OR 4.695; 95% CI 1.756–14.061) and RBC units transfused (OR 1.287; 95% CI 1.081–1.850) were independently associated with RRT need. When serum creatinine (OR 2.920, 95% CI1.056–8.074) was used in the model, the associations with RRT were also significant. Conclusion: Preoperative renal function, defined by serum creatinine or eGFR by CKD-EPI, NYHA class II–IV, and the number of blood units transfused were all independent predictors of RRT postoperatively.

Performance of glomerular filtration rate estimation equations in Congolese healthy adults: The inopportunity of the ethnic correction.

Context and objectiveIn the estimation of glomerular filtration rate (GFR), ethnicity is an important determinant. However, all existing equations have been built solely from Caucasian and Afro-American populations and they are potentially inaccurate for estimating GFR in African populations. We therefore evaluated the performance of different estimated GFR (eGFR) equations in predicting measured GFR (mGFR).MethodsIn a cross-sectional study, 93 healthy adults were randomly selected in the general population of Kinshasa, Democratic Republic of the Congo, between June 2015 and April 2016. We compared mGFR by plasma clearance of iohexol with eGFR obtained with the Modified Diet in Renal Disease (MDRD) equation with and without ethnic factor, the Chronic Kidney Disease Epidemiology (CKD-EPI) serum creatinine (SCr)-based equation, with and without ethnic factor, the cystatin C-based CKD-EPI equation (CKD-EPI SCys) and with the combined equation (CKD-EPI SCrCys) with and without ethnic factor. The performance of the equations was studied by calculating bias, precision and accuracy within 30% (P30) of mGFR.ResultsThere were 48 women and 45 men. Their mean age was 45.0±15.7 years and the average body surface area was 1.68±0.16m2. Mean mGFR was 92.0±17.2 mL/min/1.73m2 (range of 57 to 141 mL/min/1.73m2). Mean eGFRs with the different equations were 105.5±30.1 and 87.2±24.8 mL/min/1.73m2 for MDRD with and without ethnic factor, respectively; 108.8±24.1 and 94.3x20.9 mL/min/1.73m2 for CKD-EPI SCr with and without ethnic factor, respectively, 93.5±18.6 mL/min/1.73m2 for CKD-EPI SCys; 93.5±18.0 and 101±19.6 mL/min/ 1.73m2 for CKD-EPI SCrCys with and without ethnic factor, respectively. All equations slightly overestimated mGFR except MDRD without ethnic factor which underestimated by -3.8±23.0 mL/min /1.73m2. Both CKD-EPI SCr and MDRD with ethnic factors highly overestimated mGFR with a bias of 17.9±19.2 and 14.5±27.1 mL/min/1.73m2, respectively. There was a trend for better P30 for MDRD and CKD-EPI SCr without than with the ethnic factor [86.0% versus 79.6% for MDRD (p = 0.21) and 81.7% versus 73.1% for the CKD-EPI SCr equations (p = 0.057)]. CKD-EPI SCrCys and CKD-EPI SCys were more effective than creatinine-based equations.ConclusionIn the Congolese healthy population, MDRD and CKD-EPI equations without ethnic factors had better performance than the same equations with ethnic factor. The equations using Cys C (alone or combined with SCr) performed better than the creatinine-based equations.

Urinary Biomarkers to Identify Autosomal Dominant Polycystic Kidney Disease Patients With a High Likelihood of Disease Progression

IntroductionThe variable disease course of autosomal dominant polycystic kidney disease (ADPKD) makes it important to develop biomarkers that can predict disease progression, from a patient perspective and to select patients for renoprotective treatment. We therefore investigated whether easy-to-measure urinary biomarkers are associated with disease progression and have additional value over that of conventional risk markers.MethodsAt baseline, inflammatory, glomerular, and tubular damage markers were measured in 24-hour urine collections (albumin, IgG, kidney injury molecule−1 (KIM-1), N-acetyl-β-d-glucosaminidase (NAG), β2 microglobulin (β2MG), heart-type fatty acid binding protein (HFABP), macrophage migration inhibitory factor (MIF), neutrophil gelatinase-associated lipocalin (NGAL), and monocyte chemotactic protein−1 (MCP-1). Disease progression was expressed as annual change in estimated glomerular filtration rate (eGFR, Chronic Kidney Disease EPIdemiology equation), measured glomerular filtation rate (mGFR, using 125I-iothalamate), or height-adjusted total kidney volume (htTKV). Multivariable linear regression was used to assess associations of these markers independent of conventional risk markers.ResultsA total of 104 ADPKD patients were included (40 ± 11 years, 39% female, eGFR 77 ± 30, mGFR 79 ± 30 ml/min per 1.73 m2 and htTKV 852 [510−1244] ml/m). In particular, β2MG and MCP-1 were associated with annual change in eGFR, and remained associated after adjustment for conventional risk markers (standardized β = −0.35, P = 0.001, and standardized β = −0.29, P = 0.009, respectively). Adding β2MG and MCP-1 to a model containing conventional risk markers that explained annual change in eGFR significantly increased the performance of the model (final R2 = 0.152 vs. 0.292, P = 0.001). Essentially similar results were obtained when only patients with an eGFR ≥ 60 ml/min per 1.73 m2 were selected, or when change in mGFR was studied. Associations with change in htTKV were less strong.ConclusionUrinary β2MG and MCP-1 excretion were both associated with GFR decline in ADPKD, and had added value beyond that of conventional risk markers. These markers therefore have the potential to serve as predictive tools for clinical practice.

Preoperative determinant of early postoperative renal function following radical cystectomy and intestinal urinary diversion.

To identify preoperative factors correlated with postoperative early renal function in patients who had undergone radical cystectomy (RC) and intestinal urinary diversion. We retrospectively identified 201 consecutive bladder cancer patients without distant metastasis who had undergone RC at our institution between 2003 and 2012. The estimated glomerular filtration rate (eGFR) was calculated using the modified Chronic Kidney Disease Epidemiology equation before RC and 3months following RC. Univariate and stepwise multiple linear regression analyses were applied to estimate postoperative renal function and to identify significant preoperative predictors of postoperative renal function. Patients who had undergone intestinal urinary diversion and were available for the collection of follow-up data (n=164) were eligible for the present study. Median preoperative and postoperative eGFRs were 69.7 (interquartile range [IQR] 56.3-78.0) and 70.7 (IQR 57.3-78.1), respectively. In univariate analyses, age, preoperative proteinuria, thickness of abdominal subcutaneous fat tissue (TSF), preoperative serum creatinine level, preoperative eGFR, and urinary diversion type were significantly associated with postoperative eGFR. In a stepwise multiple linear regression analysis, preoperative eGFR, age, and TSF were significant factors for predicting postoperative eGFR (p<0.001, p=0.02, and p=0.046, respectively). The estimated postoperative eGFRs correlated well with the actual postoperative eGFRs (r=0.65, p<0.001). Preoperative eGFR, age, and TSF were independent preoperative factors for determining postoperative renal function in patients who had undergone RC and intestinal urinary diversion. These results may be used for patient counseling before surgery, including the planning of perioperative chemotherapy administration.

Discrepancies between the Cockcroft–Gault and Chronic Kidney Disease Epidemiology (CKD-EPI) Equations: Implications for Refining Drug Dosage Adjustment Strategies

The dosages of many medications require adjustment for renal function. There is debate regarding which equation, the Chronic Kidney Disease Epidemiology (CKD-EPI) equation vs. the Cockcroft-Gault (CG) equation, should be recommended to estimate glomerular filtration rate. We used a mathematical simulation to determine how patient characteristics influence discrepancies between equations and analyzed clinical data to demonstrate the frequency of such discrepancies in clinical practice. In the simulation, the modifiable variables were sex, age, serum creatinine, and weight. We considered estimated glomerular filtration rate results in mL/min, deindexed for body surface area, because absolute excretory function (rather than per 1.73m2 body surface area) determines the rate of filtration of a drug at a given plasma concentration. An absolute and relative difference of maximum (±) 10mL/min and 10%, respectively, were considered concordant. Clinical data for patients aged over 60years (n=9091) were available from one hospital and 25 private laboratories. In the simulation, differences between the two equations were found to be influenced by each variable but age and weight had the biggest effect. Clinical sample data demonstrated concordance between CKD-EPI and CG results in 4080 patients (45%). The majority of discordant results reflected a CG result lower than the CKD-EPI equation. With aging, the CG result became progressively lower than the CKD-EPI result. When weight increased, the opposite occurred. The choice of equation for excretory function adjustment of drug dosage will have different implications for patients of different ages and body habitus. The optimum equation for drug dosage adjustment should be defined with consideration of individual patient characteristics.

Decreased glomerular filtration rate estimated by 2009 CKD-EPI equation predicts mortality in older hip fracture population

ObjectiveWe examined estimated glomerular filtration rate using the Chronic Kidney Disease Epidemiology equation (eGFRCDK-EPI), removal of urinary catheter during hospitalization and polypharmacy as predictors of mortality in older hip fracture patients. MethodsPopulation-based prospective data were collected on 1425 consecutive hip fracture patients aged ≥65 years. Outcome was mortality at one year. Independent variables were age, sex, body mass index, fracture type, American Society of Anesthesiology score, delay to surgery, urinary catheter removal during acute hospitalization, eGFRCDK-EPI, number of daily medications, diagnosis of memory disorder, prefracture mobility and living arrangements. ResultsOf the 1425 patients, 567 (40%) had renal dysfunction on admission, 526 (37%) had their urinary catheters removed during hospitalization and 1177 (83%) were taking ≥4 medications regularly before the fracture. In the multivariate analyses with the Cox proportional hazards model adjusted simultaneously for all the independent variables, eGFRCDK-EPI 30–44ml/min/1.73m2 (HR 1.91, 95% CI 1.44–2.52) and <30ml/min/1.73m2 (HR 1.95, 95% CI 1.36–2.78), non-removal of the urinary catheter (HR 1.45, 95% CI 1.12–1.88) and large number of daily medications (4–10 HR 1.81, 95% CI 1.78–2.79, >10 HR 2.21, 95% CI 1.38–3.54) were associated with mortality. ConclusionsIn older hip fracture patients, moderate to severe level renal dysfunction measured by eGFRCDK-EPI, non-removal of urinary catheter before discharge and polypharmacy increase mortality after hip fracture. Careful assessment of renal function and medications and following the care protocols on urinary catheter removal are essential in the care of geriatric hip fracture patients.

Symptomatic BK Virus Infection Is Associated With Kidney Function Decline and Poor Overall Survival in Allogeneic Hematopoietic Stem Cell Recipients.

Nephropathy due to BK virus (BKV) infection is an evolving challenge in patients undergoing hematopoietic stem cell transplantation (HSCT). We hypothesized that BKV infection was a marker of kidney function decline and a poor prognostic factor in HSCT recipients who experience this complication. In this retrospective study, we analyzed all patients who underwent their first allogeneic HSCT at our institution between 2004 and 2012. We evaluated the incidence of persistent kidney function decline, which was defined as a confirmed reduction in estimated glomerular filtration rate of at least 25% from baseline using the Chronic Kidney Disease Epidemiology equation. Cox proportional hazard regression was used to model the cause-specific hazard of kidney function decline, and the Fine-Gray method was used to account for the competing risks of death. Among 2477 recipients of a first allogeneic HSCT, BK viruria was detected in 25% (n = 629) and kidney function decline in 944 (38.1%). On multivariate analysis, after adjusting for age, sex, acute graft-versus-host disease (GVHD), chronic GVHD, preparative conditioning regimen, and graft source, BK viruria remained a significant risk factor for kidney function decline (p < 0.001). In addition, patients with BKV infection and kidney function decline experienced worse overall survival. After allogeneic HSCT, BKV infection was strongly and independently associated with subsequent kidney function decline and worse patient survival after HSCT.