Comparison of five glomerular filtration rate estimating equations as predictors of acute kidney injury after cardiovascular surgery

Risk factors for renal impairment after liver transplantation in Mongolia: a retrospective single-center study

Background

Renal impairment (RI) is a frequent complication of liver cirrhosis and is associated with increased mortality and morbidity. Liver transplantation (LT) serves as an effective treatment method for patients with cirrhosis who have impaired renal function. However, renal function often declines after LT, influenced by various factors. This study aimed to investigate the factors contributing to RI following LT in our cases.

Methods

We analyzed the demographic data, preoperative and perioperative parameters, and postoperative outcomes of patients who underwent LT at the First Central Hospital of Mongolia from September 2011 to December 2022. Renal function was assessed by measuring the glomerular filtration rate using the Cockcroft-Gault creatinine clearance formula pretransplantation and at 24 hours, 72 hours, 7 days, 14 days, and 28 days post-LT.

Results

Several factors increased the risk of RI among recipients. These included female sex (odds ratio [OR], 3.06; 95% confidence interval [CI], 1.58-5.91), Child-Turcotte-Pugh (CTP) scores of B and C (OR, 4.23; 95% CI, 0.92-19.41 and OR, 7.68; 95% CI, 1.67-35.30, respectively), preoperative continuous renal replacement therapy (CRRT; OR, 5.86; 95% CI, 1.1-31.21), and a high graft-to-recipient weight ratio (GRWR; OR, 3.45; 95% CI, 1.23-9.63). Additionally, the survival rates for recipients with RI post-LT were 93.4% at 1 year and 78.1% at 3 years.

Conclusions

Female sex, a high CTP score, preoperative CRRT, and high GRWR were identified as risk factors for RI after LT in Mongolia.

Effect of Pravastatin on Kidney Function in Patients with Dyslipidemia and Type 2 Diabetes Mellitus: A Multicenter Prospective Observational Study

INTRODUCTION

Several studies have reported that pravastatin can mitigate the progression of kidney disease, but limited evidence exists regarding its effects on kidney function in Asian patients. This multicenter prospective observational study aimed to assess the effect of pravastatin on kidney function in Korean patients with dyslipidemia and type 2 diabetes mellitus (T2DM) in clinical practice.

METHODS

This 48-week prospective multicenter study included 2604 of 2997 eligible patients with dyslipidemia and T2DM who had available estimated glomerular filtration rate (eGFR) measurements. The primary endpoint was eGFR percent change at week 24 from baseline. We also assessed secondary endpoints, which included percent changes in eGFR at weeks 12 and 48 from baseline, as well as changes in eGFR, metabolic profiles (lipid and glycemic levels) at 12, 24, and 48 weeks from baseline, and safety.

RESULTS

We noted a significant improvement in eGFR, with mean percent changes of 2.5%, 2.5%, and 3.0% at 12, 24, and 48 weeks, respectively (all adjusted p < 0.05). The eGFR percent changes significantly increased in subgroups with baseline eGFR 30-90 mL/min/1.73 m2, glycated hemoglobin (HbA1c) ≥ 7 at baseline, no hypertension history, T2DM duration > 5 years, or previous statin therapy. Lipid profiles were improved and remained stable throughout the study, and interestingly, fasting glucose and HbA1c were improved at 24 weeks.

CONCLUSION

Our findings suggest that pravastatin may have potential benefits for improving eGFR in Korean patients with dyslipidemia and T2DM. This could make it a preferable treatment option for patients with reduced kidney function.

TRIAL REGISTRATION NUMBER

NCT05107063 submitted October 27, 2021.

Urinary peptide analysis to predict the response to blood pressure medication

BACKGROUND

The risk of diabetic kidney disease (DKD) progression is significant despite treatment with renin-angiotensin system (RAS) blocking agents. Current clinical tools cannot predict whether or not patients will respond to treatment with RAS inhibitors (RASi). We aimed to investigate whether proteome analysis could identify urinary peptides as biomarkers that could predict the response to angiotensin-converting enzyme inhibitor and angiotensin-receptor blockers treatment to avoid DKD progression. Furthermore, we investigated the comparability of the estimated glomerular filtration rate (eGFR), calculated using four different GFR equations, for DKD progression.

METHODS

We evaluated urine samples from a discovery cohort of 199 diabetic patients treated with RASi. DKD progression was defined based on eGFR percentage slope results between visits (∼1 year) and for the entire period (∼3 years) based on the eGFR values of each GFR equation. Urine samples were analysed using capillary electrophoresis-coupled mass spectrometry. Statistical analysis was performed between the uncontrolled (patients who did not respond to RASi treatment) and controlled kidney function groups (patients who responded to the RASi treatment). Peptides were combined in a support vector machine-based model. The area under the receiver operating characteristic curve was used to evaluate the risk prediction models in two independent validation cohorts treated with RASi.

RESULTS

The classification of patients into uncontrolled and controlled kidney function varies depending on the GFR equation used, despite the same sample set. We identified 227 peptides showing nominal significant difference and consistent fold changes between uncontrolled and controlled patients in at least three methods of eGFR calculation. These included fragments of collagens, alpha-1-antitrypsin, antithrombin-III, CD99 antigen and uromodulin. A model based on 189 of 227 peptides (DKDp189) showed a significant prediction of non-response to the treatment/DKD progression in two independent cohorts.

CONCLUSIONS

The DKDp189 model demonstrates potential as a predictive tool for guiding treatment with RASi in diabetic patients.

The clinical utility of cystatin C based eGFR in assessing renal function among HIV/AIDs patients on ART at Mildmay Uganda

BACKGROUND

In clinical practice, Measurement of estimated glomerular filtration rates (eGFR) is the gold standard assessing renal function the glomerular filtration rate often estimated from plasma creatinine. Several studies have shown Cystatin C based eGFR (Cys C) to be a better parameter for the diagnosis of impaired renal function. Cystatin C based eGFR has been proposed as a potential renal function marker but its use in HIV&AIDS patients has not been well evaluated.

METHODS

A cross sectional study was carried out on 914 HIV&AIDS patients on antiretroviral therapy (ART) attending Mildmay Uganda for care and treatment between January to March 2015. Serum Cystatin C based eGFR was measured using the particle enhanced immunoturbidimetric assay. Creatinine was analyzed using enzymatic Creatinine PAP method and creatinine clearance was calculated according to C&G.

RESULTS

The sensitivity of Cystatin C based eGFR was 15.1% (95% CI = 8.4, 24) with specificity 99.3% (95% CI = 98- 99.7). The positive and negative predictive values were 70.0% (95% CI 45.7-88.1) and 91.2% (95% CI 98.11-92.94) respectively. The positive likelihood ratio was 18.81 and negative likelihood ratio was 0.85. Cystatin C based eGFR had diagnostic accuracy of 90.7 and area under curve was 0.768.

CONCLUSION

Cystatin C based eGFR exhibited a high specificity and a high positive likelihood ratio in diagnosis of kidney disease among HIV&AIDS patients. Cystatin C based eGFR can be used as a confirmatory test.

Podocyte number and glomerulosclerosis indices are associated with the response to therapy for primary focal segmental glomerulosclerosis

Corticosteroid therapy, often in combination with inhibition of the renin-angiotensin system, is first-line therapy for primary focal and segmental glomerulosclerosis (FSGS) with nephrotic-range proteinuria. However, the response to treatment is variable, and therefore new approaches to indicate the response to therapy are required. Podocyte depletion is a hallmark of early FSGS, and here we investigated whether podocyte number, density and/or size in diagnostic biopsies and/or the degree of glomerulosclerosis could indicate the clinical response to first-line therapy. In this retrospective single center cohort study, 19 participants (13 responders, 6 non-responders) were included. Biopsies obtained at diagnosis were prepared for analysis of podocyte number, density and size using design-based stereology. Renal function and proteinuria were assessed 6 months after therapy commenced. Responders and non-responders had similar levels of proteinuria at the time of biopsy and similar kidney function. Patients who did not respond to treatment at 6 months had a significantly higher percentage of glomeruli with global sclerosis than responders (p < 0.05) and glomerulosclerotic index (p < 0.05). Podocyte number per glomerulus in responders was 279 (203-507; median, IQR), 50% greater than that of non-responders (186, 118-310; p < 0.05). These findings suggest that primary FSGS patients with higher podocyte number per glomerulus and less advanced glomerulosclerosis are more likely to respond to first-line therapy at 6 months. A podocyte number less than approximately 216 per glomerulus, a GSI greater than 1 and percentage global sclerosis greater than approximately 20% are associated with a lack of response to therapy. Larger, prospective studies are warranted to confirm whether these parameters may help inform therapeutic decision making at the time of diagnosis of primary FSGS.

Comparing five equations to calculate estimated glomerular filtration rate to predict acute kidney injury following total joint arthroplasty

BACKGROUND

Acute kidney injury (AKI) following total joint arthroplasty (TJA) is associated with increased morbidity and mortality. Estimated glomerular filtration rate (eGFR) is used as an indicator of renal function. The purpose of this study was (1) to assess each of the five equations that are used in calculating eGFR, and (2) to evaluate which equation may best predict AKI in patients following TJA.

METHODS

The National Surgical Quality Improvement Program (NSQIP) was queried for all 497,261 cases of TJA performed from 2012 to 2019 with complete data. The Modification of Diet in Renal Disease (MDRD) II, re-expressed MDRD II, Cockcroft-Gault, Mayo quadratic, and Chronic Kidney Disease Epidemiology Collaboration equations were used to calculate preoperative eGFR. Two cohorts were created based on the development of postoperative AKI and were compared based on demographic and preoperative factors. Multivariate regression analysis was used to assess for independent associations between preoperative eGFR and postoperative renal failure for each equation. The Akaike information criterion (AIC) was used to evaluate predictive ability of the five equations.

RESULTS

Seven hundred seventy-seven (0.16%) patients experienced AKI after TJA. The Cockcroft-Gault equation yielded the highest mean eGFR (98.6 ± 32.7), while the Re-expressed MDRD II equation yielded the lowest mean eGFR (75.1 ± 28.8). Multivariate regression analysis demonstrated that a decrease in preoperative eGFR was independently associated with an increased risk of developing postoperative AKI in all five equations. The AIC was the lowest in the Mayo equation.

CONCLUSIONS

Preoperative decrease in eGFR was independently associated with increased risk of postoperative AKI in all five equations. The Mayo equation was most predictive of the development of postoperative AKI following TJA. The mayo equation best identified patients with the highest risk of postoperative AKI, which may help providers make decisions on perioperative management in these patients.

Comparison of Race-Based and Non-Race-Based Glomerular Filtration Rate Equations for the Assessment of Renal Functional Risk Before Nephrectomy

OBJECTIVE

To compare the performance of race-based and race-neutral estimated glomerular filtration rate (eGFR) calculators in patients undergoing kidney surgery.

METHODS

Analysis of institutional kidneys surgeries from 2006-2021 was conducted. Demographics, serum creatinine (SCr), protein dipstick, and creatinine clearance (CrCl) were assessed within 1 week prior to surgery. SCr was used to calculate eGFR using 3 models: Modification of Diet in Renal Disease (MDRD), Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI 2009), and CKD-EPI 2021. Patients were classified based on Kidney Disease: Improving Global Outcomes (KDIGO) criteria for CKD staging and prognosis, with urine CrCl treated as benchmark for analysis. Receiver operating characteristic (ROC) analysis evaluated accuracy of eGFR calculators' binary discrimination of eGFR less than 60 mL/min. CKD stage agreement between eGFR and urine CrCl was assessed.

RESULTS

A total of 554 kidney surgeries in 336 patients had necessary laboratory data for analysis. The cohort was 62% male, with a median age of 47. Within this cohort, 8.1% (n=45) were Black, and 80% (n=441) were White. glomerular filtration rate (GFR) from 24-hour urine CrCl normalized by BSA did not vary significantly from eGFR by SCr based calculators. The proportion of patients with eGFR <60 significantly differed when using Modification of Diet in Renal Disease, CKD-EPI 2009, and CKD-EPI 2021 equations when compared to CrCl (P<.001). Still, they performed equivalently in the staging of CKD, as well as in predicting GFR of less than 60, and classifying CKD prognosis of "moderately increased or higher".

CONCLUSION

A race-neutral eGFR calculator can perform equivalently to established eGFR calculators, with the added benefit of mitigating biases that account for racial disparities in nephrectomy decision making.

Novel Nanotechnology-Driven Prototypes for AI-Enriched Implanted Prosthetics Following Organ Failure

Meeting medical challenges posed by global burdens is proven to be of primary interest. One example is the COVID-19 epidemic that humankind is currently experiencing, since around December 2019. Innovation is key to respond rapidly and effectively to sanitary and health emergencies, when human lives are severely threatened. In this scenery, medical devices that can be rapidly launched in the market and manufactured at scale are crucial for saving lives. One example is a lifesaving respiratory device launched in about 10 days (Mercedes F1 team's new device based on continuous positive airway pressure devices) and rapidly approved by international agencies responsible for assuring drug and medical devices safety, in response to the COVID-19 burden. Remarkably, it is the first time in history that mankind observes disease spread reaching such high proportions, globally, in such short time scale. However, while this epidemic had, in March 2020, reached the critical figures of about 38,000 deaths and c. 738,000 infected, organ donation and transplantation patients are suffering for years, accounting for an increasing number of affected, annually. These patients are invisible for the general public. Therefore, this chapter approaches the organ donation and transplantation burden, proposing effective solutions to leverage the suffering, improving life quality of patients enduring several underlying issues, from hemodialysis complications and critical organ failure to lacking compatible donors. This, on the basis of technology repurposing, to speed up approval processes followed by international agencies responsible for assuring drug and medical devices safety, while adding innovative methods to existing technology and reducing invasiveness.

Factors associated with acute kidney injury in patients undergoing extracorporeal membrane oxygenation: retrospective cohort

OBJECTIVE

To identify factors associated with acute kidney injury in patients undergoing extracorporeal membrane oxygenation.

METHOD

Retrospective cohort study conducted in an adult Intensive Care Unit with patients undergoing extracorporeal membrane oxygenation from 2012 to 2021. The research used the Kidney Disease Improving Global Outcomes as criteria for definition and classification of acute kidney injury. A multiple logistic regression model was developed to analyze the associated factors.

RESULTS

The sample was composed of 122 individuals, of these, 98 developed acute kidney injury (80.3%). In multiple regression, the associated factors found were vasopressin use, Nursing Activities Score, and glomerular filtration rate.

CONCLUSION

The use of vasopressin, the Nursing Activities Score, and the glomerular filtration rate were considered as factors related to the development of acute kidney injury in patients undergoing extracorporeal membrane oxygenation.

Kidney disease burden in an Asian Indian population: Effect of the new 2021 serum creatinine CKD-EPI equation

AIMS

CKD-EPI (chronic kidney disease-epidemiological) serum creatinine equation is widely accepted for calculating estimated glomerular filtration rate (eGFR). The effect of transitioning from the older 2009 to the newer race-independent 2021 CKD-EPI equation on the estimated kidney disease burden (eKDB) was studied in an Asian-Indian population.

METHODS

The study included 1156 adults, the two equations were compared for agreement (Bland-Altman and Cohen's kappa) and concordance (Lin's correlation and test for proportions).

RESULTS

The 2021 CKD-EPI increased the eGFR (positive-bias), independent of age-group, gender or presence of type 2 diabetes mellitus (T2DM) and hypertension (HTN). Thus, the eKDB was significantly decreased by 2021 CKD-EPI equation. The agreement was highest for the age-group 31-40 years (95.8 % versus 87.5 % for > 50 years). Besides, the eGFR category was shifted from G3 to G1 in 8.2 % (95 % CI: 6.8-9.9) individuals by 2021 CKD-EPI. The effect of transition on eKDB was greater in individuals > 50 years (7.4 %) or with HTN (6.3 %).

CONCLUSION

In comparison to the old equation, the 2021 CKD-EPI equation increased the eGFR, lowering the eKDB in this Asian-Indian cohort. The degree of lowering was affected by age-group, and presence of T2DM /HTN, but independent of gender.

Dismantling "Race" in Health Research

In this era of confronting racism in public space, it is critical to keep addressing the covert systemic racism in the healthcare system. We want to bring attention to the continued unscientific practice of race-based medicine and the absurdity of treating race as a biological indicator in the 21st century. We believe race is a social construct that does not qualify as a scientific biological indicator for predicting health outcomes. In this paper, we first present arguments for inappropriate use of race in health research and then discuss alternative explanations for health disparity findings that use race as a predictor. Our main concern centers on two specific aspects of the concept of "race": (1) its fundamental lack of scientific basis as a predictor for health outcomes, (2) the misguided narrative that the term creates, placing the onus of racial discrimination on the victim, instead of highlighting the act of discrimination and the role researchers play in actively reinforcing racism when using "race" as a variable. We conclude by proposing that "race" be replaced by the variable "racism" in health.

The predictive value of creatinine clearance for mortality in patients undergoing revascularization

Background

Renal function plays a significant role in the prognosis and management of patients with multi-vessel coronary artery disease (CAD) referred for revascularization. Current data lack precise risk stratification using estimated glomerular filtration rate (eGFR) and creatinine clearance.

Methods

This prospective study includes a three-year follow-up of 1112 consecutive patients with multi-vessel CAD enrolled in the 22 hospitals in Israel that perform coronary angiography.

Results

The Mayo formula yielded the highest mean eGFR (90 ± 26 mL/min per 1.73m²) and chronic kidney disease-epidemiology collaboration (CKD-EPI) the lowest (76 ± 24 mL/min per 1.73m²). Consequently, the Mayo formula classified more patients (56%) as having normal renal function. There was a significant and strong correlation between the values obtained from all five formulas using Cockcroft-Gault as the reference formula: Mayo: r = 0.80, p < 0.001; CKD-EPI: r = 0.87, p < 0.001; modification of diet in renal disease (MDRD): r = 0.84, p < 0.001; inulin clearance-based: r = 0.99, p < 0.001). Multivariable analysis demonstrated that decreased renal function is an independent predictor of 3-year mortality in all five formulas, with risk increasing by 15–25% for each 10-unit decrease in eGFR. Despite the similarities between the formulas, the ability to predict mortality was highest in the Mayo formula and lowest in MDRD.

Conclusions

Our data suggest that while the Mayo formula is not currently recommended by any nephrology guidelines, it may be an alternative formula to predict mortality among patients with multivessel CAD, including to the widely used MDRD formula.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13019-021-01502-1.