Early Changes In Renal Function Research Articles

Renal Ultrasound Elastography: A Review of the Previous Reports on Chronic Kidney Diseases

The early detection of a kidney injury is essential to protect against the progression of kidney damage owing to the progressive nature of chronic kidney disease. A renal biopsy is the gold standard for the assessment of pathological alterations such as interstitial fibrosis and glomerulosclerosis. However, there are concerns regarding potential complications including bleeding and a reduction in renal function. Ultrasound elastography is an ideal modality for assessing the alterations in various organs and diagnosing malignant tumors. This technique has the potential to help detect early changes in renal function and pathological alterations. However, the careful application and interpretation of this technique in the kidney is required because of its complex hemodynamics and architecture. Shear wave elastography is the most widely investigated technique among ultrasound elastography. This review aims to summarize the previous investigations of the kidney using shear wave elastography, particularly for renal malignancy, kidney transplantation, and chronic kidney disease. Additionally, we have highlighted the influencing factors concerning the practical measurement of renal elasticity.

Do Estimated Glomerular Filtration Rate Differs With Respect to Atherogenic Index of Plasma (AIP) and BMI in Identifying Early Changes In Renal Function in Obesity? : A Comparative Study.

Do Estimated Glomerular Filtration Rate Differs With Respect to Atherogenic Index of Plasma (AIP) and BMI in Identifying Early Changes In Renal Function in Obesity? : A Comparative Study.

Impacts of right ventricular function and venous congestion on renal response during depletion in acute heart failure.

AimsVenous congestion is a major determinant of worsening renal function (WRF) in acute decompensated heart failure (ADHF), particularly when associated with right ventricular (RV) dysfunction. Whether the individual impacts of hemodynamic variables on renal outcomes in ADHF is modified according to RV function remains unclear. We aimed to determine the association between hemodynamic parameters and early changes in renal function during depletive therapy and explore the association of these changes with clinical outcomes.Methods and resultsWRF was defined as any increase in creatinine after 24 h of depletive therapy and improvement in renal function (IRF) as any decrease. Assessments were prospectively obtained on admission, 24 h later and at discharge. Out of the 105 patients enrolled, 45% had IRF, and 41% had poor RV. At baseline, patients evolving towards IRF had a lower mean arterial pressure (84.7 ± 13.9 vs. 90.9 ± 15.2 mmHg), a lower renal perfusion pressure (69.4 ± 16.2 vs. 75.4 ± 15.1 mmHg), and a poorer RV function (tricuspid annular plan systolic excursion 16.5 ± 6.0 vs. 18.8 ± 5.6 mm) in comparison with those with WRF (all P < 0.05). In a multivariate linear regression model, tricuspid annular plane systolic excursion was the dominant parameter correlated with early changes in creatinine when RV was poor (β = 0.337), whereas mean arterial pressure (β = −0.334) and cardiac output (β = −0.298) were the only parameters correlated with renal function in patients with preserved RV function (all P < 0.05). RV dysfunction, but not early changes in renal function, was associated with post‐discharge clinical events.ConclusionsRV dysfunction is a predictor of an early but transient progression to IRF during depletive therapy. RV dysfunction modifies the individual impact of various hemodynamic variables on the early trajectory of renal function in ADHF.

Evaluation of Renal Function in Children with Congenital Scoliosis and Congenital Anomalies of the Kidney and Urinary Tract.

BackgroundThe aim of this study was to compare renal function in children with congenital scoliosis and congenital anomalies of the kidney and urinary tract, with healthy children.Material/MethodsBiochemical tests were performed before surgery (pre-therapy) and after surgery (post-therapy) in 16 children with congenital scoliosis and congenital anomalies of the kidney and urinary tract. Thirty-two healthy children were matched for age, sex, and weight (healthy controls). General renal function tests included serum electrolytes, creatinine, urea, cystatin C, and estimated glomerular filtration rate (eGFR). Tests for early renal changes included N-acetyl-beta-D-glucosaminidase (NAG), urine microalbumin, serum transferrin, immunoglobulin G (IgG), urinary alpha-1-microglobulin (A1M), and beta-2-microglobulin (B2M).ResultsSixteen patients with congenital anomalies of the kidney and urinary tract included eight boys (mean age, 11.38±2.00 years) and eight girls (mean age, 11.00±2.78 years). There were no significant differences in renal function between the pre-therapy and post-therapy groups (P>0.05), or between the three groups (pre-therapy, post-therapy, and healthy controls). In the pre-therapy group, there were significant differences in IgG, A1M, NAG, and serum phosphate levels between boys and girls, urine microalbumin was significantly increased in girls, but not boys (P<0.05). There were no significant differences between the pre-therapy group and post-therapy group (P>0.05).ConclusionsRoutine tests of renal function were normal in children with congenital scoliosis and congenital anomalies of the kidney and urinary tract, but early changes in renal function occurred before surgical treatment, indicating long-term follow-up of renal function is recommended.

Left Renal Cortical Thickness Measured by Ultrasound Can Predict Early Progression of Chronic Kidney Disease

Aims: The kidney becomes atrophic in advanced chronic kidney disease, and renal size and parenchymal volume correlate with renal function. However, alterations in renal parenchymal volume have not been adequately studied in terms of the renal cortex and medulla. We investigated the relationship between the changes in the renal cortex and medulla and renal function. Methods: Renal ultrasound (US) parameters including renal length, parenchymal thickness, cortical thickness and medullary thickness were assessed in 176 subjects, who were categorized into 4 groups based on the estimated glomerular filtration rate (ml/min/1.73 m²): group 1, ≥90; group 2, ≥60 but <90; group 3, ≥30 but <60; and group 4, <30. Renal US parameters in both kidneys were compared among the 4 groups. Results: We found stepwise associations in renal length, cortical thickness and parenchymal thickness with decreased renal function. Medullary thickness showed no changes among groups 1-3. Multiple linear regression analysis including sex, age and renal US parameters showed that only renal length was an independent predictor of renal function. When analyzed in groups 1-3, cortical thickness was the strongest associated parameter. Lower cortical left/right ratio (left cortical thickness/right cortical thickness) showed a stepwise association with a decrease in renal function. Conclusion: Renal length and cortical thickness measured by US were correlated with renal function. In particular, left cortical thickness could help to detect early changes in renal function.

Early changes in renal function and late cardiovascular disease risk in testicular cancer survivors with 25 years follow-up.

4541 Background: Cisplatin-based chemotherapy (CT) for testicular cancer (TC) leads to an increased cardiovascular disease (CVD) risk, related to endothelial damage by circulating platinum levels o...

Novel biomarkers of acute kidney injury: Evaluation and evidence in urologic surgery.

Patients undergoing urologic surgery are at risk of acute kidney injury (AKI) and consequently long-term deterioration in renal function. AKI is further associated with significantly higher odds of perioperative complications, prolonged hospital stay, higher mortality and costs. Therefore, better awareness and detection of AKI, as well as identification of AKI determinants in the urological surgery setting is warranted to pre-empt and mitigate further deterioration of renal function in patients at special risk. New consensus criteria provide precise definitions of diagnosis and description of the severity of AKI. However, they rely on serum creatinine (SCr), which is known to be an inaccurate marker of early changes in renal function. Therefore, several new urinary and serum biomarkers promise to address the gap associated with the use of SCr. Novel biomarkers may complement SCr measurement or most likely improve the diagnostic accuracy of AKI when used in combinations. However, novel biomarkers have to prove their clinical applicability, accuracy, and cost effectiveness prior to implementation into clinical practice. Most preferably, novel biomarkers should help to positively improve a patient's long-term renal functional outcomes. The purpose of this review is to discuss currently available biomarkers and to review their clinical evidence within urologic surgery settings.

Subtle changes in renal function are associated with differences in late survival following adult cardiac surgery

To determine the predictors of post-operative renal function following adult cardiac surgery, and to assess the influence of this on late survival. Prospectively collected data were analysed on 8032 patients who underwent coronary artery bypass grafting, valve surgery or combined procedures from 1 January 1998 until 31 December 2008, who did not require preoperative renal replacement therapy. The estimated glomerular filtration rate (eGFR) was calculated by the Modification of Diet in Renal Disease formula accounting for ethnicity pre-operatively, post-operatively on the fourth post-operative day, and the post-operative nadir based upon the peak post-operative creatinine within 30 days of surgery. Late survival data were obtained from the UK Central Cardiac Audit Database (CCAD). Appropriate frailty analyses were conducted in R and model fit was compared using Aikaike's Information Criterion. Initial analysis intended to determine predictors of post-operative renal function including pre-operative eGFR, EuroSCORE and surgical procedure including the operative procedure and bypass time. Further analysis examined its influence on late survival. Median follow-up was 72 months (IQR 48-105) during which there were 904 late deaths. The most powerful predictor of the day 4 eGFR was the pre-operative eGFR but other factors contributed including increasing EuroSCORE and bypass time. The pre-operative eGFR was shown to be a strong and independent predictor of late outcome (P = 0.0001, HR 0.497 95%CI 0.434-564); however, model fit was significantly improved using the day 4 eGFR (P = 0.0001, HR 0.43 95%CI 0.385-0.482). No specific change in individual renal function was identified as a predictor of adverse late survival, and neither the pre-operative nor day 4 eGFR was predictive of the nadir of renal function. Subtle early changes in renal function at the time of surgery are powerful predictors of adverse late outcome and can be predicted by pre-operative renal function.

Association of G-137C Interleukin-18 Promoter Polymorphism With Early Renal Glomerulus Injury in Liver Transplantation Recipients

As renal injury after transplantation is associated with increased cardiovascular events, mortality, and hepatic allograft dysfunction, early recognition of renal injury and implementing changes may improve the long-term outcome of transplantation. A common cause of renal failure after allo-liver transplantation is calcineurin inhibitor toxicity. However, several other potential causes may also contribute to renal injury after liver transplantation. Recently, interleukin (IL)-18 has been found to have an early and important role in renal injury after transplantation (1). Two single-nucleotide polymorphisms (A-607 C and G-137C) in the promoter region of the IL-18 gene have been repeatedly found to be associated with the IL-18 promoter transcription activity (2). We investigated whether the A-607C and G-137 C IL-18 promoter polymorphism were associated with early renal injury in liver transplantation recipients. Reliance on serum creatinine typically leads to an overestimation of renal function in patients after transplantation. Microproteinuria as a hallmark of reflecting early changes in the glomeruli and proximal tubular function can be used as an accurate predictor to monitor early changes in renal function. We included 152 liver transplantation patients. The recipients were all in a stable stage with normal serum creatinine. The patient with hepatitis C virus and hepatitis B virus infection and diabetes mellitus after transplantation were excluded. When the urine immunoglobulin elevated, we defined this patient had an early renal glomerulus injury (ERGI) and divided the patients into ERGI group (n=37) and no ERGI group (n=115). When the urine α1-microglobulin elevated, we define this patient had an early renal tubular injury (ERTI) and divided the patients into ERTI group (n=106) and no ERTI group (n=46). There is no difference of drug used in those groups (see Table, Supplemental Digital Content 1, https://links.lww.com/TP/A350). We found significant differences in the genotype frequency (P=0.027) and allele frequency (P=0.034) between the ERGI and no ERGI in G-137C IL-18 promoter polymorphism. The GG genotype was significantly more frequent in ERGI compared with no ERGI (Table 1). The genotype and allele frequencies of the G-607C IL-18 promoter polymorphism were not significantly different between the early renal injury groups (see Table, Supplemental Digital Content 2, https://links.lww.com/TP/A351). We can see the tendency that the ERGI and ERTI recipients had higher IL-18 serum levels. However, there was no significant difference (see Figure, Supplemental Digital Content 3, https://links.lww.com/TP/A352).TABLE 1: Analysis on allele and genotype frequencies (%) of IL-18 polymorphism G–137C in alloliver recipients with or without early renal injuryIn conclusion, our study investigated the influence of the G-137C IL-18 promoter polymorphism on early renal injury after liver transplantation. We found that the polymorphism in the IL-18 promoter at position G-137C is associated with an increased risk of ERGI after liver transplantation. The −137GG homozygote was significantly more frequent in ERGI in liver transplantation. As we know that this is the first time to find the relationship between IL-18 gene polymorphism and early renal injury after liver transplantation. The earlier diagnosis of renal injury could lead to more timely intervention, and potentially, to better patient outcomes. This genotype may be a useful marker of ERGI after liver transplantation. Yi Li1 Bin Yang1 Bei Cai1 Lanlan Wang1 Department of Clinical Immunological Laboratory West China Hospital, Sichuan University Chengdu, Sichuan, People's Republic of China Binwu Ying2 Department of Clinical Molecular Laboratory West China Hospital, Sichuan University Chengdu, Sichuan, People's Republic of China Yunying Shi3 Department of Nephrology West China Hospital, Sichuan University Chengdu, Sichuan, People's Republic of China

Variation of serum creatinine, cystatin C, and creatinine clearance tests in persons with normal renal function

Background To determine the potential sensitivity of several renal function tests for detecting early changes in renal function, we compared the within-individual (W-I) variation over 5 months of serum creatinine, serum cystatin C, and creatinine clearance. Methods On 31 healthy subjects, blood and timed urine specimens were collected once each month to get 6 collections. Creatinine (enzymatic) in serum and urine and cystatin C (immunonephelometric) in serum were measured and glomerular filtration rate (GFR) by creatinine clearance and the Modification of Diet in Renal Disease (MDRD) equation were calculated. To compare W-I variations between different creatinine methods, we also measured creatinine by both enzymatic and kinetic alkaline picrate methods on 15 sets of frozen samples. Results For the 31 volunteers, the mean W-I variations for serum creatinine (5.8%) and cystatin C (5.4%) were both much lower than the W-I variation of creatinine clearance (18.7%). As expected, the MDRD GFR had a similar W-I variation (6.7%) to that of serum creatinine and its values were markedly different than GFR by creatinine clearance. On the 15 sets of frozen samples, the W-I variation of creatinine measured by the enzymatic method (CV 5.2%) was slightly less than by the picrate method (CV 6.2%). Conclusions The low W-I variation of both serum cystatin C and serum creatinine suggests that serial measurements of either would detect a changes in renal function earlier than would GFR by creatinine clearance or MDRD equation, which allows reporting only for GFRs < 60 ml/min/1.7 m 2. While we measured only creatinine clearance, the large variability, difficulty, and cost of all clearance measurements make them impractical for routine monitoring of patients.

Obesity augments vasoconstrictor reactivity to angiotensin II in the renal circulation of the Zucker rat

Obesity is an emerging risk factor for renal dysfunction, but the mechanisms are poorly understood. Obese patients show heightened renal vasodilation to blockade of the renin-angiotensin system, suggesting deficits in vascular responses to angiotensin II (ANG II). This study tested the hypothesis that obesity augments renal vasoconstriction to ANG II. Lean (LZR), prediabetic obese (OZR), and nonobese fructose-fed Zucker rats (FF-LZR) were studied to determine the effects of obesity and insulin resistance on reactivity of blood pressure and renal blood flow to vasoconstrictors. OZR showed enlargement of the kidneys, elevated urine output, increased sodium intake, and decreased plasma renin activity (PRA) vs. LZR, and renal vasoconstriction to ANG II was augmented in OZR. Renal reactivity to norepinephrine and mesenteric vascular reactivity to ANG II were similar between LZR and OZR. Insulin-resistant FF-LZR had normal reactivity to ANG II, indicating the insulin resistance was an unlikely explanation for the changes observed in OZR. Four weeks on a low-sodium diet (0.08%) to raise PRA reduced reactivity to ANG II in OZR back to normal levels without effect on LZR. From these data, we conclude that in the prediabetic stages of obesity, a decrease in PRA is observed in Zucker rats that may lead to increased renal vascular reactivity to ANG II. This increased reactivity to ANG II may explain the elevated renal vasodilator effects observed in obese humans and provide insight into early changes in renal function that predispose to nephropathy in later stages of the disease.

Histamine ameliorates anti-glomerular basement membrane antibody-induced glomerulonephritis in rats

Anti-glomerular basement membrane (anti-GBM)-induced glomerulonephritis involves T-helper type 1 (Th1) responses leading to rapid crescent formation. As many inflammatory and immune responses in general are affected by histamine, we examined the effects of histaminergic ligands on immune renal injury in the rat. Female Wistar-Kyoto rats were injected intraperitoneally with an antibody against the GBMs. Histaminergic ligands were then injected twice daily for 5 days after which renal function was assessed by proteinuria. Treatment with histamine led to significant dose-dependent reductions in proteinuria compared to the control antibody-injected group and markedly decreased the number of crescentic glomeruli and macrophage infiltration of the glomeruli. Furthermore, histamine significantly decreased the plasma concentration of interleukin-12, a Th1-type cytokine compared to the antibody-injected control animals. Dimaprit, an H(2)/H(4) agonist, mimicked the effects of histamine on proteinuria and crescent formation. Clozapine, an H(4) agonist, tended to mimic the effects of histamine, whereas an H(1), mepyramine, or an H(2) antagonist, ranitidine, did not reverse the protective effect of histamine. We suggest that histamine may alleviate renal injury in anti-GBM glomerulonephritis by suppressing the immune response.

Detection of early changes in renal function using 99mTc-MAG3 imaging in a murine model of ischemia-reperfusion injury

Accurate determination of renal function in mice is a major impediment to the use of murine models in acute kidney injury. The purpose of this study was to determine whether early changes in renal function could be detected using dynamic gamma camera imaging in a mouse model of ischemia-reperfusion (I/R) injury. C57BL/6 mice (n = 5/group) underwent a right nephrectomy, followed by either 30 min of I/R injury or sham surgery of the remaining kidney. Dynamic renal studies (21 min, 10 s/frame) were conducted before surgery (baseline) and at 5, 24, and 48 h by injection of (99m)Tc-mercaptoacetyltriglycine (MAG3; approximately 1.0 mCi/mouse) via the tail vein. The percentage of injected dose (%ID) in the kidney was calculated for each 10-s interval after MAG3 injection, using standard region of interest analyses. A defect in renal function in I/R-treated mice was detected as early as 5 h after surgery compared with sham-treated mice, identified by the increased %ID (at peak) in the I/R-treated kidneys at 100 s (P < 0.01) that remained significantly higher than sham-treated mice for the duration of the scan until 600 s (P < 0.05). At 48 h, the renal scan demonstrated functional renal recovery of the I/R mice and was comparable to sham-treated mice. Our study shows that using dynamic imaging, renal dysfunction can be detected and quantified reliably as early as 5 h after I/R insult, allowing for evaluation of early treatment interventions.

Chromium-induced early changes in renal function among ferrochromium-producing workers

Urinary biochemical indicators of renal injury were examined in 84 male and 38 female ferrochromium-producing workers exposed to water-soluble chromium compounds [Cr(VI)]. The indicators examined included urinary chromium (U-Cr), alkaline phosphatase (ALP), gamma-glutamyl transferase (γ-GT), glutamic-oxalacetic and glutamic-pyruvic transaminases (GOT & GPT), lactate dehydrogenase (LDH), N- acetyl-β- d- glucosaminidase (NAG), total protein (TPr) and β 2-microglobulin ( β 2-MG). The U-Cr levels in the exposed group were approximately 1.8 times that of the control group. Compared to controls, the activities of γ-GT, NAG, ALP, GOT and LDH in the urine of workers were significantly increased whenever U-Cr concentration exceeded 45 μg/g creatinine. The activities of γ-GT, GOT and NAG were elevated in workers employed for longer than ten years. However, no clear dose-response relationships nor time-effect relationships were found. The present results suggest that long-term exposure to water-soluble chromium [Cr(VI)] produces chronic renal injury. The site of the injury appears to mainly involve the proximal tubule. U-Cr concentrations of > 15 μg/g creatinine can be proposed as a threshold dosage for nephrotoxicity, and γ-GT, NAG and ALP are early sensitive indicators of the most valuable for evaluating the renal injury.

Uranyl nitrate acute renal failure in the dog: early changes in renal function and haemodynamics.

1. Sodium excretion, plasma renin acitivity (PRA), inulin clearance, total renal blood flow (RBF), renal cortical radiomicrosphere distribution and systemic administration of uranyl nitrate (19.9 mumol/kg body wt.; 10 mg/kg) in the dog. 2. During the 3 h of study after uranyl nitrate, urine flow remained stable or increased, sodium excretion increased approximately fivefold, renal vascular resistance increased threefold, and concordant decreases in RBF and inulin clearance to 40-50% of control values occured. At 3 h total cortical RBF decreased to 35% of control values and the ration of blood flow in outer to inner cortical zones also decreased, reflecting outer cortical ischaemia, PRA increased in the first hour after uranyl nitrate and slowly declined therafter, though not to control values. 3. Respiratory rate, heart rate, mean systemic blood pressure and cardiac output were unchanged after uranyl nitrate, demonstrating that the changes in renal vascular resistance occurred without a change in peripheral vascular resistance. 4. It is postulated that increased renin-angiotensin system activity mediates the change in renal haemodynamics and the consequent fall in glomerular filtration.