Estimation Of Kidney Function Research Articles

Elimination of race in estimates of kidney function to provide unbiased clinical management in Canada

KEY POINTS For many years, the universally used equation for estimating risk of kidney disease (the kidney function estimate, Chronic Kidney Disease Epidemiology Collaboration [CKD-EPI] equation), included an adjustment for Black race that led to an upward correction in estimated glomerular

Method of Calculating Renal Function Estimates Could Inappropriately Exclude Transgender Patients Receiving Gender-Affirming Hormone Therapy from Pre-Exposure Prophylaxis Eligibility.

Purpose: Despite the importance of reliable renal function estimation among the growing transgender population, research describing the variability of existing equations is scarce. Study objectives were to (1) quantify the range of renal function estimates that would be observed if different gender coefficients are used in the estimating equations, (2) compare estimates of renal function (creatinine clearance [CLCR] or estimated glomerular filtration rate [GFR]) between users and nonusers of gender-affirming therapies, and (3) quantify the proportion of subjects who would be deemed ineligible for tenofovir disoproxil fumarate/emtricitabine (TDF/FTC) for pre-exposure prophylaxis (PrEP) based on the gender coefficient used. Methods: A retrospective analysis was performed among transgender PrEP users enrolled in a multicenter observational study between June 2017 and October 2021. The primary outcome was estimated kidney function, defined using calculated CLCR or GFR before initiating TDF/FTC for PrEP based on the three most commonly used estimating equations. Results: A total of 258 participants were evaluated. Median differences in renal function ranged from 13 to 25 mL/min based on which gender coefficient and equation was used. Regardless of the method used to compute renal function, there were significant differences between users and nonusers of gender-affirming therapy. There were 17 (6.6%) participants where at least one of the methods would potentially render them ineligible to receive TDF/FTC for PrEP. Conclusions: Renal function estimates vary considerably with different estimating equations in the transgender population and are modified by use of gender-affirming therapy. These variations could result in exclusion from drug therapies such as TDF/FTC for PrEP.

PCRRT Expert Committee ICONIC Position Paper on Prescribing Kidney Replacement Therapy in Critically Sick Children With Acute Liver Failure.

Management of acute liver failure (ALF) and acute on chronic liver failure (ACLF) in the pediatric population can be challenging. Kidney manifestations of liver failure, such as hepatorenal syndrome (HRS) and acute kidney injury (AKI), are increasingly prevalent and may portend a poor prognosis. The overall incidence of AKI in children with ALF has not been well-established, partially due to the difficulty of precisely estimating kidney function in these patients. The true incidence of AKI in pediatric patients may still be underestimated due to decreased creatinine production in patients with advanced liver dysfunction and those with critical conditions including shock and cardiovascular compromise with poor kidney perfusion. Current treatment for kidney dysfunction secondary to liver failure include conservative management, intravenous fluids, and kidney replacement therapy (KRT). Despite the paucity of evidence-based recommendations concerning the application of KRT in children with kidney dysfunction in the setting of ALF, expert clinical opinions have been evaluated regarding the optimal modalities and timing of KRT, dialysis/replacement solutions, blood and dialysate flow rates and dialysis dose, and anticoagulation methods.

The effect of gender-affirming hormone treatment on serum creatinine in transgender and gender-diverse youth: implications for estimating GFR.

Equations for estimated glomerular filtration rate (eGFR) based on serum creatinine include terms for sex/gender. For transgender and gender-diverse (TGD) youth, gender-affirming hormone (GAH) treatment may affect serum creatinine and in turn eGFR. TGD youth were recruited for this prospective, longitudinal, observational study prior to starting GAH treatment. Data collected as part of routine clinical care were abstracted from the medical record. For participants designated male at birth (DMAB, N = 92), serum creatinine decreased within 6months of estradiol treatment (mean ± SD 0.83 ± 0.12mg/dL to 0.76 ± 0.12mg/dL, p < 0.001); for participants designated female at birth (DFAB, n = 194), serum creatinine increased within 6months of testosterone treatment (0.68 ± 0.10mg/dL to 0.79 ± 0.11mg/dL, p < 0.001). Participants DFAB treated with testosterone had serum creatinine similar to that of participants DMAB at baseline, whereas even after estradiol treatment, serum creatinine in participants DMAB remained higher than that of participants DFAB at baseline. Compared to reference groups drawn from the National Health and Nutritional Examination Survey, serum creatinine after 12months of GAH was more similar when compared by gender identity than by designated sex. GAH treatment leads to changes in serum creatinine within 6months of treatment. Clinicians should consider a patient's hormonal exposure when estimating kidney function via eGFR and use other methods to estimate GFR if eGFR based on serum creatinine is concerning.

High serum cystatin C levels in juvenile myelomonocytic leukemia patients without abnormal kidney function.

In pediatric cancer patients, the estimated glomerular filtration rate based on serum cystatin C (CysC) was reported to be suitable for estimating kidney function because of low serum creatinine (Cr) and high serum β2-microglobulin. Recently, however, serum CysC levels have been reported to be elevated in some cancer patients other than those with juvenile myelomonocytic leukemia (JMML), regardless of normal kidney function. We describe two pediatric cases of JMML with an elevated serum CysC level. Urinalysis tests showed no abnormalities and no evidence of nephritis or nephropathy, and there were no findings indicating abnormal kidney function, such as Cr clearance in one case or the estimated glomerular filtration rate based on serum Cr in both cases, except for the serum CysC levels. There were no other causes of a high serum CysC level, including hyperthyroidism and steroid administration. The patients were treated with a conventional dosage of drugs, and their serum CysC levels decreased to the normal range when they were in complete remission after treatment. An elevated serum CysC level may reflect tumor burden independent of kidney function in JMML patients. Therefore, creatinine or inulin clearance should be determined to more accurately estimate kidney function for administering an optimal dose of anticancer drugs. In addition, a high serum CysC level may be a potential biomarker of cancer progression.

Removal of race from estimation of kidney function.

Removal of race from estimation of kidney function.

Resolving the Debate: The Future of Using Race in Estimating Kidney Function.

Racial and social unrest witnessed during 2020 ignited a national conversation about the appropriateness of the use of race in health care algorithms and in the estimation of kidney function in particular. The growing concerns over the use of race in kidney function-estimating equations prompted the National Kidney Foundation (NKF) and American Society of Nephrology to launch an effort for change by establishing a task force on reassessing the use of race in diagnosing kidney disease. After nearly a year examining the evidence and obtaining testimony from experts and stakeholders, the task force recommended the immediate implementation of the 2020 Chronic Kidney Disease-Epidemiology creatinine equation refit without race in all US laboratories; increased routine use of cystatin C for confirmation of estimated glomerular filtration rate in clinical decision-making and a call for research on glomerular filtration rate estimation with new endogenous filtration markers and on addressing disparities in health and health care. The NKF and American Society of Nephrology strongly encouraged rapid adoption of these new recommendations. Leadership efforts of the NKF have begun to lay the foundation for national implementation through laboratory engagement, clinician awareness, and patient education.

Comparing two equations for estimation of kidney function (Cockcroft-Gault and Glomerular Filtration Rate Assessment in Liver Disease) for vancomycin dosing in adult liver transplant recipients: a pilot, randomized clinical trial

Background: In the setting of impaired liver function, estimation of glomerular filtration rate (GFR) using common creatinine-based equations is inaccurate. Recently, the Glomerular filtration Rate Assessment In Liver disease (GRAIL) model has been introduced to estimate GFR in liver transplantation. This study was conducted to compare vancomycin dose adjustment in liver transplant patients using Cockcroft-Gault (C-G) versus the GRAIL method. Methods: In this pilot, randomized clinical trial, adult liver transplant recipients who were a candidate to receive intravenous vancomycin were enrolled. The level of kidney function was estimated using the GRAIL model and C-G equation in the intervention and control arms, respectively. Then, vancomycin maintenance doses were accordingly adjusted. At the steady state, peak and trough serum concentrations of vancomycin were collected for area under the concentration-time curve (AUC) calculation and pharmacokinetic comparisons. Results: Fifteen patients were enrolled in each arm of study. The mean daily dose of vancomycin was estimated insignificantly lower for individuals in the GRAIL arm than the C-G group (1550.00±544.45 versus 1750.00± 389.60mg). Compared with the C-G group, a higher rate of patients in the GRAIL arm experienced below-target vancomycin trough concentrations (40.0% versus 13.3%), and a lower rate showed above target trough concentration (40.0% versus 66.7%). These differences did not reach statistical significance. Individuals in the GRAIL arm represented significantly higher rate of below target vancomycin AUC/MIC than patients in the C-G arm (46.7% versus 6.7%) (P=0.049). No differences in clinical outcomes were observed between the two groups. Conclusion: Using the GRAIL model for vancomycin dosing may result in less percent of patients with at target AUC/MIC compared to the C-G method and expose more patients at risk for vancomycin under dosing.

Time to Rethink the Current Paradigm for Assessing Kidney Function in Drug Development and Beyond.

Chronic kidney disease (CKD) is an important health issue that affects ~ 9.1% of the world adult population. Serum creatinine is the most commonly used biomarker for assessing kidney function and is utilized in different equations for estimating creatinine clearance or glomerular filtration rate (GFR). The Cockcroft-Gault formula for adults and "original" Schwartz formula for children have been the most commonly used equations for estimating kidney function during the last 3-4 decades. Introduction of standardized serum creatinine bioanalytical methodology has reduced interlaboratory variability but is not intended to be used with Cockcroft-Gault or original Schwartz equations. More accurate equations (for instance, Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) for adults and bedside Schwartz or Chronic Kidney Disease in Children Schwartz equation for children) based on standardized serum creatinine values (and another biomarker-cystatin C) have been introduced and validated in recent years. Recently, the CKD-EPI equation refitted without a race variable was introduced. Clinical practice guidance in nephrology advocates a shift to these equations for managing health care of patients with CKD. The guidance also recommends use of albuminuria in addition to GFR for CKD diagnosis and management. Significant research with large data sets would be necessary to evaluate whether this paradigm would also be valuable in drug dose adjustments. This article attempts to highlight some important advancements in the field from a clinical pharmacology perspective and is a call to action to industry, regulators, and academia to rethink the current paradigm for assessing kidney function to enable dose recommendation in patients with CKD.

Serum Creatinine-to-Cystatin-C Ratio as a Potential Muscle Mass Surrogate and Racial Differences in Mortality

Serum creatinine-based estimated glomerular filtration rate equations and muscle mass are powerful markers of health and mortality risk. However, the serum creatinine-to-cystatin-C ratio may be a better indicator of health status. The objective of this study was to describe the relationship between creatinine-to-cystatin-C ratio and all-cause mortality when stratifying patients as per race and as per chronic kidney disease status. This was a retrospective cohort study examining black and nonblack US veterans between October 2004 and September 2019, with baseline cystatin C and creatinine data from those not on dialysis during the study period. Veterans were divided into four creatinine-to-cystatin-C ratio groups: <0.75, 0.75-<1.00, 1.0-<1.25, and ≥1.25. The primary outcome of interest was all-cause mortality subsequent to the cystatin C laboratory measure. Among 22,316 US veterans, the mean (±standard deviation) age of the cohort was 67±14years, 5% were female, 82% were nonblack, and 18% were black. The proportion of black veterans increased across creatinine-to-cystatin-C ratio groups. In the fully adjusted model, compared with the reference (creatinine-to-cystatin-C ratio: 1.00-<1.25), a creatinine-to-cystatin-C ratio <0.75 had the highest mortality risk among both black and nonblack veterans (nonblack: hazard ratio [HR] [95% confidence interval {CI}]: 3.01 [2.78-3.26] and black: 4.17 [3.31-5.24]). A creatinine-to-cystatin-ratio ≥1.25 was associated with lower death risk than the referent in both groups (nonblack: HR [95% CI]: 0.89 [0.80-0.99] and black: HR [95% CI]: 0.55 [0.45-0.69]). However, there was a significant difference in the effect by race (Wald's P-value: <0.01). Higher creatinine-to-cystatin-C ratios indicate better health status and are strongly associated with lower mortality risk regardless of the kidney function level, and the relation was similar for both black and nonblack veterans, but with different strengths of effect across racial groups. Thereby, use of a fixed race coefficient in estimating kidney function may be biased.

Cystatin c – a marker of kidney function and predictor of cardiovascular disease and mortality

Over the past decade, serum cystatin C (SCC) has been often suggested as a marker of kidney function. Strong evidence has shown that SCC may improve classification of the glomerular filtration rate (GFR) to identify chronic kidney disease in certain clinical populations. SCC equations based on the SCC reference standard are considered state–of–the–art to estimate kidney function and the latest chronic kidney disease guidelines included several suggestions and recommendations that relate to SCC. The results of several previous studies have also suggested that SCC may be more useful than just a marker of GFR, as it may also be useful as a clinical marker to provide complementary information to established risk determinants, especially for high–risk populations. Additionally, other studies have reported that SCC may be a useful prognostic indicator of cardiovascular disease.

Change in tartrate-resistant acid phosphatase isoform 5b levels, a marker of bone metabolism, in patients with chronic hepatitis B treated with tenofovir alafenamide.

Hepatitis B virus (HBV) infection is associated with the risk of osteoporosis and bone mineral density (BMD) loss. Tenofovir alafenamide (TAF) is associated with a slightly lower degree of BMD loss compared with tenofovir disoproxil, without loss of the excellent anti-HBV effects. The aim of the present study was to verify the effect of bone metabolism in patients with HBV treated with TAF. A total of 87 patients were treated with TAF. Of these, 32 patients were treatment naïve, and 55 patients were treated with entecavir (ETV) for at least 1 year, after which ETV was switched to TAF. At the start of TAF and after 1 year, BMD in the lumbar and neck of the femur, tartrate-resistant acid phosphatase isoform 5b (TRACP-5b) levels as a marker of bone metabolism and serum inorganic phosphorus (P) were compared to estimate bone metabolism. Serum creatinine (Cr), cystatin C, urine protein and β2 microglobulin levels were evaluated to estimate kidney function. Treatment with TAF for 1 year decreased TRACP-5b levels, particularly in patients with bone disease, except for a minimal significant change (MSC; decrease of 12.4%) in TRACP-5b levels. The change in rate of TRACP-5b levels were positively associated with changes in P, Cr-estimated glomerular filtration rate and TRACP-5b levels at the start of TAF. Logistic regression analysis showed that increased BMD in the lumbar region contributed to the switch from ETV to TAF. TAF induced a decrease in TRACP-5b levels in patients with HBV. Bone disease was a contributing factor for MSC. Since TRACP-5b can be used as a marker of bone metabolism and fractures, TAF may exhibit potential in preventing fractures in patients with HBV.

Health inequities and the inappropriate use of race in nephrology.

Chronic kidney disease is an important clinical condition beset with racial and ethnic disparities that are associated with social inequities. Many medical schools and health centres across the USA have raised concerns about the use of race — a socio-political construct that mediates the effect of structural racism — as a fixed, measurable biological variable in the assessment of kidney disease. We discuss the role of race and racism in medicine and outline many of the concerns that have been raised by the medical and social justice communities regarding the use of race in estimated glomerular filtration rate equations, including its relationship with structural racism and racial inequities. Although race can be used to identify populations who experience racism and subsequent differential treatment, ignoring the biological and social heterogeneity within any racial group and inferring innate individual-level attributes is methodologically flawed. Therefore, although more accurate measures for estimating kidney function are under investigation, we support the use of biomarkers for determining estimated glomerular filtration rate without adjustments for race. Clinicians have a duty to recognize and elucidate the nuances of racism and its effects on health and disease. Otherwise, we risk perpetuating historical racist concepts in medicine that exacerbate health inequities and impact marginalized patient populations.

Race, Genetic Ancestry, and Estimating Kidney Function in CKD

BackgroundThe inclusion of race in equations to estimate the glomerular filtration rate (GFR) has become controversial. Alternative equations that can be used to achieve similar accuracy without the use of race are needed.MethodsIn a large national study involving adults with chronic kidney disease, we conducted cross-sectional analyses of baseline data from 1248 participants for whom data, including the following, had been collected: race as reported by the participant, genetic ancestry markers, and the serum creatinine, serum cystatin C, and 24-hour urinary creatinine levels.ResultsUsing current formulations of GFR estimating equations, we found that in participants who identified as Black, a model that omitted race resulted in more underestimation of the GFR (median difference between measured and estimated GFR, 3.99 ml per minute per 1.73 m2 of body-surface area; 95% confidence interval [CI], 2.17 to 5.62) and lower accuracy (percent of estimated GFR within 10% of measured GFR [P10], 31%; 95% CI, 24 to 39) than models that included race (median difference, 1.11 ml per minute per 1.73 m2; 95% CI, −0.29 to 2.54; P10, 42%; 95% CI, 34 to 50). The incorporation of genetic ancestry data instead of race resulted in similar estimates of the GFR (median difference, 1.33 ml per minute per 1.73 m2; 95% CI, −0.12 to 2.33; P10, 42%; 95% CI, 34 to 50). The inclusion of non-GFR determinants of the serum creatinine level (e.g., body-composition metrics and urinary excretion of creatinine) that differed according to race reported by the participants and genetic ancestry did not eliminate the misclassification introduced by removing race (or ancestry) from serum creatinine–based GFR estimating equations. In contrast, the incorporation of race or ancestry was not necessary to achieve similarly statistically unbiased (median difference, 0.33 ml per minute per 1.73 m2; 95% CI, −1.43 to 1.92) and accurate (P10, 41%; 95% CI, 34 to 49) estimates in Black participants when GFR was estimated with the use of cystatin C.ConclusionsThe use of the serum creatinine level to estimate the GFR without race (or genetic ancestry) introduced systematic misclassification that could not be eliminated even when numerous non-GFR determinants of the serum creatinine level were accounted for. The estimation of GFR with the use of cystatin C generated similar results while eliminating the negative consequences of the current race-based approaches. (Funded by the National Institute of Diabetes and Digestive and Kidney Diseases and others.)

Impact of glomerular filtration rate estimation on cardiovascular events in elderly patients undergoing coronary angiography.

Estimation of kidney function by glomerular filtration rate (eGFR) is affected by age and is important for decision making regarding treatment and prognosis of patients with cardiovascular disease. We investigated the impact of eGFR on long-term cardiovascular outcomes in an elderly population undergoing coronary angiography for evaluation or treatment of coronary artery disease. GFR was estimated according to Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation in 3690 elderly patients (aged 70-100 years) undergoing coronary angiography. Patients receiving maintenance dialysis were excluded. The association between eGFR and major adverse cardiovascular events (MACE) including myocardial infarction, ischemic stroke or death, was investigated. GFR was further calculated according to modification of diet in renal disease (MDRD) and the Cockcroft-Gault equations, and compatibility between estimations was analyzed. Cardiovascular comorbidities were more prevalent with the reduction in kidney function as was the proportion of patients presenting with acute coronary syndromes. The adjusted hazard ratio (95% confidence interval) for MACE during a mean follow-up of 5 years was 0.95 (0.77-1.16), 1.04 (0.84-1.29), 1.56 (1.16-1.84), 2.22 (1.65-2.97) and 3.74 (2.20-6.38) in patients with eGFR 60-89, 45-59, 30-44, 15-29 and <15 ml/min/1.73m2, respectively, compared to >90 ml/min/1.73m2. Reclassification of eGFR stages by MDRD (upward 23.8%, downward 0.4%) and Cockcroft-Gault (upward 4.3%, downward 28.1%) compared to CKD-EPI estimation, was noted. However, the association between eGFR stages and MACE was similar between equations. Kidney function, as manifested by eGFR, has a graded inverse association with the burden of cardiovascular comorbidities and long-term adverse events in elderly patients undergoing coronary angiography.

Kidney Age Index (KAI): A novel age-related biomarker to estimate kidney function in patients with diabetic kidney disease using machine learning

Background and objectiveWith aging, patients with diabetic kidney disease (DKD) show progressive decrease in kidney function. We investigated whether the deviation of biological age (BA) from the chronological age (CA) due to DKD can be used (denoted as Kidney Age Index; KAI) to quantify kidney function using machine learning algorithms. MethodsThree large datasets were used in this study to develop KAI. The machine learning algorithms were trained on PREVEND dataset with healthy subjects (N = 7963) using 13 clinical markers to predict the CA. The trained model was then used to predict the BA of patients with DKD using RENAAL (N = 1451) and IDNT (N = 1706). The performance of four traditional machine learning algorithms were evaluated and the KAI = BA-CA was estimated for each patient. ResultsThe neural network model achieved the best performance and predicted the CA of healthy subjects in PREVEND dataset with a mean absolute deviation (MAD) = 6.5 ± 3.5 years and pearson correlation = 0.62. Patients with DKD showed a significant higher KAI of 15.4 ± 11.8 years and 13.6 ± 12.3 years in RENAAL and IDNT datasets, respectively. ConclusionsOur findings suggest that for a given CA, patients with DKD shows excess BA when compared to their healthy counterparts due to disease severity. With further improvement, the proposed KAI can be used as a complementary easy-to-interpret tool to give a more inclusive idea into disease state.

Estimation of kidney function in patients with primary neuromuscular diseases: is serum cystatin C a better marker of kidney function than creatinine?

BackgroundUsing serum creatinine leads to an overestimation of kidney function in patients with primary neuromuscular disorders, and reduced kidney function may remain undetected. Cystatin C (CysC) could provide a better estimation.AimTo evaluate the precision, accuracy, and bias of two creatinine-, one cystatin C-based and one combined equation to estimate glomerular filtration rate (eGFR) in patients with primary neuromuscular disease.Patients and methodsOf the 418 patients initially identified at the out-patient clinic, data on kidney function was obtained for 145 adult patients (age 46 ± 14 years, BMI 26 ± 6 kg/m2) with primary neuromuscular disease. Kidney function was measured by iohexol clearance, and blood samples for serum creatinine and CysC were drawn simultaneously. Bias was defined as the mean difference between eGFR and measured iohexol clearance, and accuracy as the proportion of eGFRs within ± 10% (P10) of measured clearance.ResultsKidney function (iohexol clearance) was 81 ± 19 (38–134) ml/min/1.73m2. All equations overestimated kidney function by 22–60 ml/min/1.73m2. eGFR CysC had the lowest bias overall 22 (95% CI 20–26) ml/min/1.73m2 also at all levels of kidney function we evaluated (at 30–59 ml/min/1.73m2 bias was 27 (95% CI 21–35), at 60–89 it was 25 (95% CI 20–28) and at ≥ 90 it was 12 (95% CI 7–22)). eGFR CysC also had the best accuracy in patients with reduced kidney function (P10 was 5.9% at 30–59 ml/min/1.73m2).ConclusionsCystatin C-based estimations of kidney function performed better than creatinine-based ones in patients with primary neuromuscular disease, but most importantly, all evaluated equations overestimated kidney function, especially in patients with reduced kidney function. Therefore, kidney function should be measured by gold-standard methods when precision and accuracy are needed.Graphic abstract

Estimating Glomerular Filtration Rate in Cirrhosis Using Creatinine-Based and Cystatin C-Based Equations: Systematic Review and Meta-Analysis.

Accurate estimation of kidney function in cirrhosis is crucial for prognosis and decisions regarding dual-organ transplantation. We performed a systematic review/meta-analysis to assess the performance of creatinine-based and cystatin C (CysC)-based eGFR equations compared with measured GFR (mGFR) in patients with cirrhosis. A total of 25 studies (n = 4565, 52.0 years, 37.0% women) comprising 18 equations met the inclusion criteria. In all GFR equations, the creatinine-based equations overestimated GFR (standardized mean difference, SMD, 0.51; 95% confidence interval [CI], 0.31-0.71) and CysC-based equations underestimated GFR (SMD, -0.3; 95% CI, -0.60 to -0.02). Equations based on both creatinine and CysC were the least biased (SMD, -0.14; 95% CI, -0.46 to 0.18). Chronic kidney disease-Epi-serum creatinine-CysC (CESC) was the least biased but had low precision and underestimated GFR by -3.6 mL/minute/1.73 m2 (95% CI, -17.4 to 10.3). All equations significantly overestimated GFR (+21.7 mL/minute/1.73 m2 ; 95% CI, 17.7-25.7) at GFR <60 mL/minute/1.73 m2 ; of these, chronic kidney disease-Epi-CysC (10.3 mL/minute/1.73 m2 ; 95% CI, 2.1-18.4) and GFR Assessment in Liver Disease (12.6 mL/minute/1.73 m2 ; 95% CI, 7.2-18.0) were the least biased followed by Royal Free Hospital (15 mL/minute/1.73 m2 ; 95% CI, 5.5-24.6) and Modification of Diet in Renal Disease 6 (15.7 mL/minute/1.73 m2 ; 95% CI, 10.6-20.8); however, there was an overlap in the precision of estimates, and the studies were limited. In ascites, overestimation of GFR was common (+8.3 mL/minute/1.73 m2 ; 95% CI, -3.1 to 19.7). However, overestimation of GFR by 10 to 20 mL/minute/1.73m2 is common in patients with cirrhosis with most equations in ascites and/or kidney dysfunction. A tailored approach is required especially for decisions regarding dual-organ transplantation.

A Step Toward Health Equity for Veterans: Evidence Supports Removing Race From Kidney Function Calculations

The practice of race-based medicine fails to recognize that race cannot be used as a proxy for genetic ancestry and that racial and ethnic categories are complex sociopolitical constructs without biological basis. Clinical algorithms and equations that incorporate race modifiers and are currently considered standard for diagnosis and management of disease are appropriately being scrutinized for lack of biological plausibility and their role in exacerbating health inequities. In this paper, we review the history, evidence, and implications of using a Black race coefficient when calculating estimated glomerular filtration rate (eGFR) in the diagnosis and management of kidney disease.Currently, the US Department of Veterans Affairs (VA) uses the Modification of Diet in Renal Disease (MDRD) equation for eGFR. This equation includes a Black race coefficient that results in an eGFR that is 21% higher for a Black patient when compared with a patient of any other race. The rationale for the inclusion of this coefficient is based on racist science that incorrectly assumes race as a proxy for genetic ancestry. Multiple studies across diverse Black populations demonstrate that the application of a race coefficient in kidney function estimation equations is inferior when compared with the race-neutral option. Furthermore, the most utilized eGFR equations are biased and imprecise. Because eGFR is the primary diagnostic method for detecting and managing kidney disease, preventing its progression, planning for dialysis, and evaluating for transplantation, it is vital that eGFR be as accurate, precise, and equitable as possible.The incorporation of a race coefficient in kidney estimation equations lacks biological plausibility and its use exacerbates kidney health disparities. Until a better method to estimate kidney function becomes available, a race-neutral option for current estimation equations should be applied for all patients.

Advances in management of hepatorenal syndrome.

Hepatorenal syndrome (HRS) is encountered frequently in patients with end-stage liver disease and remains an important cause of morbidity and mortality in this patient population. This review will focus and provide updates on pathophysiology, assessment of kidney function, new definitions, and treatment and prevention of HRS. Pathophysiology of HRS has been elucidated more recently and in addition to hemodynamic changes, the role of systemic inflammatory response contributes significantly to this process. Assessment of kidney function in patients with liver cirrhosis remains challenging. Novel glomerular filtration rate equations have been developed in patients with liver disease to better estimate kidney function and changes made in the definition of acute kidney injury (AKI), which are more aligned with KDIGO criteria for AKI. Vasoconstrictors, especially terlipressin, along with albumin remain the mainstay of pharmacological treatment of HRS-AKI. Biomarkers have been useful in differentiating ATN from HRS at an early stage. HRS remains a significant cause of morbidity and mortality for patients with end-stage liver disease. Newer understanding of mechanisms in development and pathophysiology of HRS have helped with elucidation of the disease process.