Chronic and End-Stage Kidney Disease in the Neurological Intensive Care Unit.

Patients with renal disease have increased rates of admission to the neurological intensive care unit related to overlapping risk factors for renal and cerebrovascular disease as well as unique risks associated with renal dysfunction alone. Management of acute neurological injury in these patients requires individualized attention to diagnostic and management factors as they relate to coagulopathy, disorders of immune function, encephalopathy and renal replacement modalities. Careful consideration of these brain-kidney interactions is necessary to optimize care for this special patient population and improve neurological and renal outcomes.

Manipulating the gut microbiome to decrease uremic toxins.

The uremic solute indoxyl sulfate has been associated with increased mortality and other adverse outcomes in patients with chronic kidney disease. In a recent study published in Cell Host & Microbe, Devlin et al. describe a novel approach to alter the production of indoxyl sulfate through manipulation of the gut microbiota. Although this approach is far from clinical application, it may allow investigators to determine the contribution of uremic solutes to disease pathogenesis.

Survival of Dialysis Patients with Restless Legs Syndrome: A 15-Year Follow-Up Study.

BACKGROUND: Restless legs syndrome, also known as Willis/Ekbom disease (RLS/WED), is a sleep-related, sensorimotor disorder with a high prevalence among end-stage renal disease (ESRD) patients undergoing haemodialysis (HD) (about 15-40%). Whether RLS/WED in uremic patients influences cardiovascular morbidity and mortality remains a matter of controversy. The aim of this study was to evaluate the relationship of RLS/WED and mortality in a population of chronically dialyzed patients. METHOD: In 1996, we studied 128 patients with ESRD undergoing HD; 47 subjects (36.7%) complained RLS/WED symptoms. Fifteen years later we evaluated the mortality of this population. No clinical follow-up examination of the uremic population was made. The Kaplan-Maier curves in dialysis patients with or without RLS/WED (control group matched for age) were constructed for all-cause mortality and compared using log-rank test. RESULTS: The Kaplan-Maier curves disclosed a lower mortality rate in the uremic patients with RLS/WED than in those without RLS/WED (p = 0.04). In our analysis, the mortality rate was not influenced by RLS/WED severity (p = 0.11) or gender (p = 0.15). No difference among the causes of death was found in the 2 groups. CONCLUSIONS: Our study suggests that mortality in ESRD patients is not influenced by concomitant RLS/WED. After a 15-year follow-up, survival rates in our cohort were significantly longer in uremic subjects with RLS/WED than in those without RLS/WED. Finally, we found no relationship between RLS/WED severity and mortality.

Lower Hydrogen Sulfide Is Associated with Cardiovascular Mortality, Which Involves cPKCßII/Akt Pathway in Chronic Hemodialysis Patients.

BACKGROUND/AIMS: To evaluate the relationship between plasma hydrogen sulfide (H2S) and cardiovascular risk markers, including pulse pressure (PP), left ventricular mass index (LVMI) and intima-media thickness (IMT), and mortality in chronic hemodialysis (CHD) patients and further investigate the underlying cardiovascular protection mechanism of H2S. METHODS: CHD patients, 113 of them, were studied. Plasma H2S was measured through zinc acetate reaction. cPKCßII membrane translocation and phosphorylation of Akt were detected by western blot. RESULTS: Lower plasma H2S level in CHD patients was predictor of an increased PP, LVMI and IMT. Patients with lower H2S had a lower survival at the end of the study. H2S was an independent predictor of all-cause and cardiovascular mortality when adjusted for other risk factors. CHD patients with lower H2S showed an increase of cPKCßII activation, but phosphorylation of Akt decreased. The level of VCAM-1 and ICAM-1 increased significantly. CONCLUSIONS: Lower plasma H2S in CHD patients is associated with cardiovascular risk factors and mortality, which may be mediated by the cPKCßII/Akt pathway and further VCAM-1/ICAM-1 upregulation.

Prognostic values of left atrial strain analyzed by four-dimensional speckle tracking echocardiography in uremia with preserved ejection fraction.

Little is known about the prognostic value of left atrial strain by four-dimensional speckle-tracking echocardiography in end-stage renal disease patients with preserved left ventricular ejection fraction. This prospective study collected clinical and echocardiographic data from 80 stable dialysis patients (mean age 57 ± 10 years; 62.5% men). All patients underwent the dedicated four-dimensional speckle-tracking echocardiography to measure LASr (peak longitudinal strain of reservoir function), LAScd (peak longitudinal strain of conduit function), LASct (peak longitudinal strain of contractile function), LASr_c (peak circumferential strain of reservoir function), LAScd_c (peak circumferential strain of conduit function) and LASct_c (peak circumferential strain of contractile function). These patients were enrolled from August 2021 to August 2023 and followed-up for 19 months (interquartile-range 15 to 20 months). The primary outcome was a composite of all-cause mortality or major adverse cardiovascular events (MACEs). The study patients were classified into event (developed mortality or MACEs) and event-free group according to the primary outcome. Multivariate Cox regression analysis was used to investigate risk factors for all-cause mortality or MACEs. The event group had lower LASr (16.4% vs. 21.2%, P = 0.0003), LASct (8.2% vs. 11.2%, P = 0.01), LASr_c (25.2% vs. 35.0%, P = 0.0004) and LASct_c (14.9% vs. 20.9%, P = 0.001) than the event-free group. Using optimal cut-off value determined by ROC curve, the less LASr (LASr < 18.5%), LASct (LASct < 8.5%), LASr_c (LASr_c < 28.5%), and LASct_c (LASct_c < 17.5%) group had a higher mortality or MACEs rate. Multivariate cox regression analyses revealed that LASr (HR = 0.81, 95% CI [0.17; 0.91], P = 0.0005, per 1% increase) and LASr_c (HR = 0.93, 95% CI [0.87; 0.98], P = 0.01, per 1% increase) were independent predictors of all-cause mortality or MACEs. Less peak longitudinal and circumferential strains of reservoir function are predictive of poor prognosis among end-stage renal disease patients with preserved left ventricular ejection fraction.

Association between indoxyl sulfate and cardiac dysfunction and prognosis in patients with dilated cardiomyopathy.

BACKGROUND: Serum indoxyl sulfate (IS) is a uremic toxin that accelerates the progression of chronic kidney disease (CKD). The aim of this study was to determine whether serum IS is associated with hemodynamic parameters or cardiac events in patients with nonischemic dilated cardiomyopathy (DCM). METHODS AND RESULTS: The 76 patients with DCM had their serum IS and plasma brain natriuretic peptide (BNP) levels measured, and underwent echocardiographic examination. Mean (± standard deviation) left ventricular ejection fraction (LVEF) and BNP levels in the patients were 32.5 ± 10.7% and 204 ± 219 pg/ml, respectively. Patients were divided into 2 groups, low IS (<0.9 µg/ml) and high IS (≥ 0.9 µg/ml), based on the median value of serum IS. Although there were no significant differences in LVEF and BNP between the groups, E/e' was significantly greater in the high IS group than in the low IS group. Furthermore, E/e' was an independent determinant of serum IS level. The risk of a cardiac event was significantly higher in the high IS group than in the low IS group (P=0.014). Moreover, serum IS was a significant predictor of cardiac events even after adjustment for BNP. CONCLUSIONS: Cardiac dysfunction is associated with the serum IS level, which might serve as a new prognostic marker in DCM patients with normal renal function or mild to moderate CKD.

Hepatocellular carcinoma in uremic patients: is there evidence for an increased risk of mortality?

BACKGROUND AND AIM: The clinical aspects of patients with hepatocellular carcinoma (HCC) undergoing maintenance dialysis are largely unknown. We aimed to investigate the long-term survival and prognostic determinants of dialysis patients with HCC. METHODS: A total of 2502 HCC patients, including 30 dialysis patients and 90 age, sex, and treatment-matched controls were retrospectively analyzed. RESULTS: Dialysis patients more often had dual viral hepatitis B and C, lower serum α-fetoprotein level, worse performance status, higher model for end-stage liver disease (MELD) score than non-dialysis patients and matched controls (P all < 0.05). There was no significant difference in long-term survival between dialysis and non-dialysis patients and matched controls (P = 0.684 and 0.373, respectively). In the Cox proportional hazards model, duration of dialysis < 40 months (hazard ratio [HR]: 6.67, P = 0.019) and ascites (HR: 5.275, P = 0.019) were independent predictors of poor prognosis for dialysis patients with HCC. Survival analysis disclosed that the Child-Turcotte-Pugh (CTP) provided a better prognostic ability than the MELD system. Among the four currently used staging systems, the Japan Integrated Scoring (JIS) system was a more accurate prognostic model for dialysis patients; a JIS score ≥ 2 significantly predicted a worse survival (P = 0.024). CONCLUSIONS: Patients with HCC undergoing maintenance dialysis do not have a worse long-term survival. A longer duration of dialysis and absence of ascites formation are associated with a better outcome in dialysis patients. The CTP classification is a more feasible prognostic marker to indicate the severity of cirrhosis, and the JIS system may be a better staging model for outcome prediction.

Plasma beta-2 microglobulin is associated with cardiovascular disease in uremic patients.

Since beta-2 microglobulin (B2M) is a surrogate marker for middle molecular weight uremic toxins and the major protein component in dialysis-related amyloidosis, it has been frequently studied in dialysis patients. It is not known, however, whether B2M has an impact in patients with chronic kidney disease (CKD) not yet on dialysis. Here we studied the relationship of plasma B2M levels to clinical and cardiovascular outcomes in 142 patients (mean age of 67 years) at different stages of CKD. B2M levels increased with CKD stage and thus were highest in hemodialysis patients. Baseline B2M levels were associated with vascular calcification but not with arterial stiffness or bone density. During a mean follow-up of 969 days, 44 patients died and 49 suffered a cardiovascular event. Higher B2M levels were independently associated with overall and cardiovascular mortality and cardiovascular events in the whole cohort and with cardiovascular events in the predialysis cohort. Moreover, B2M appeared to be a better predictor than well-established factors associated with outcomes in this population, such as estimated glomerular filtration rate ((eGFR), only for predialysis patients), inflammation biomarkers, and other factors included in a propensity score. Thus, we confirm the strong relationship between B2M levels and eGFR and confirm the power of B2M to predict overall and cardiovascular mortality and cardiovascular events in patients at different stages of CKD.

Effect of dialyzer membranes on mortality in uremic patients undergoing long-term hemodialysis: A Nationwide population-based study using the Taiwan Dialysis Registry Data System 2005-2012.

The characteristics in dialyzer are associated with mortality in patients with end-stage renal disease (ESRD) receiving hemodialysis (HD). This study is to investigate the effects of dialyzer membranes on 3-year mortality in ESRD patients. From the long-term nationwide population database. Prevalent HD patients during 2005-2012 were enrolled. Our main analysis to calculate the effect was cox regression multivariate model. Overall, the mean age of all population (N = 73 565) was 61.0 ± 13.6 years, the observation period is 2.46 years ±0.98 within 3 years and 64.6% used polysulfone (PS), polymethyl methacrylate (PMMA) (11.6%), polyethersulfone (11.4%), and cellulose triacetate (CTA) (10.7%), ethylene vinyl alcohol (EVAL) (hazard ratio [HR] 2.72, 95% confidence interval [CI] 1.71-4.33) and CTA (HR 1.35, 95% CI 1.12-1.64) were associated with higher mortality than PS, but PMMA was not. EVAL and CTA adversely affected mortality and PMMA had no protective role. Further investigations on membrane characters on HD patients are warranted. Taipei Medical University (TMU) (TMU-JIRB (No. N201804051).

Sodium thiosulfate-based treatment in calcific uremic arteriolopathy: a consecutive case series.

BACKGROUND: Calcific uremic arteriolopathy (CUA) is a rare complication in end stage renal disease with high mortality. Numerous case reports and one case series of 3 patients report the benefit of sodium thiosulfate (STS) for treatment of CUA. The purpose of this evaluation was to examine the response to a STS-based treatment approach in patients with CUA with 1 year follow up. METHODS: A retrospective case series of 6 consecutive patients from Manitoba, Canada who met predefined diagnostic criteria for CUA and received STS between 2006 and 2008 were included. STS responders were defined as improvement in at least one of the following three parameters: pain severity, wound size and diagnostic imaging/radiography. Mortality, STS dose, duration, adverse events and cost were also collected. RESULTS: Four patients were classified as responders. The 2 responders who survived at 1 year of follow-up demonstrated an improvement in all 3 parameters examined including an improvement in their follow-up diagnostic imaging results within the first 4 - 6 weeks of STS treatment. At 1 year of follow-up, 3 patients died. CONCLUSION: Using an STS-based multifaceted treatment approach for CUA, 4 patients responded but 3 of 6 patients died within 1 year. Further larger prospective studies are needed to delineate STS responders from non-responders.

Life expectancy of Chinese patients with chronic kidney disease without dialysis.

AIM: Long term dialysis is life-saving for patients with end stage renal disease (ESRD). However, in ESRD patients with multiple comorbid conditions, dialysis may actually be futile, and conservative management is advisable. We studied the life expectancy of Chinese ESRD patients treated conservatively. METHODS: We reviewed 63 consecutive ESRD patients who were treated conservatively in our centre. Duration of survival was calculated from the date of initial assessment for dialysis, as well as the expected date of needing dialysis based on previous trend of renal function decline. RESULTS: At the end of the observation period, 55 patients died. Twelve patients died before the expected date of needing dialysis because of unrelated reasons, while 36 deaths were directly attributed to uraemia. The median overall survival after initial assessment for dialysis was 41.3 months (95% confidence interval (CI), 33.2 to 49.4 months). The median overall survival was 6.58 months (inter-quartile range, 0.92 to 9.33 months) from the theoretical date of needing dialysis. The survival from the theoretical date of needing dialysis did not correlate with patient age, sex, diabetic status, or baseline renal function. CONCLUSIONS: In Chinese ESRD patients treated conservatively, the median survival is around 6 months after the theoretical date of needing dialysis. Our result provides an important piece of information for the decision of dialysis and patient counselling.

Inferior survival outcomes of pancreas transplant alone in uremic patients.

Theoretically, pancreas transplant alone in uremic (PTAU) patients could also be one of the options for those waiting for both pancreas and kidney grafts, but it has never been reported. There were 160 cases of pancreas transplant in this study, including 16% PTAU. The 5-year patient survival was 66.2% after PTAU, 94.5% after SPK, 95.8% after PAK, and 95.4% after PTA. Rejection of pancreas graft was significantly lower in PTAU group (3.8%), followed by 16.7% in pancreas after kidney transplant (PAK), 29.8% in simultaneous pancreas and kidney transplant (SPK) and 37.0% in pancreas transplant alone (PTA). Fasting blood sugar and serum HbA1c levels after PTAU were not significantly different from those by other subgroups. The 5-year death-censored pancreas graft survival was 100% after PTAU and PAK, and 97.0% after SPK and 77.9% after PTA. However, the 5-year death-uncensored pancreas graft survival was 67.0% after PTAU, 100% after PAK, 91.3% after SPK, and 74.0% after PTA. The superior graft survival in the PTAU group was achieved only if deaths with a functioning graft were censored. In conclusion, given the inferior patient survival outcome, PTAU is still not recommended unless SPK and PAK is not available. Although PTAU could be a treatment option for patients with diabetes complicated by end-stage renal disease (ESRD) in terms of surgical risks, endocrine function, and immunological and graft survival outcomes, modification of the organ allocation policies to prioritize SPK transplant in eligible patients should be the prime goal.

New Insights into the Role of FGF-23 and Klotho in Cardiovascular Disease in Chronic Kidney Disease Patients.

Alterations of fibroblast growth factor 23 (FGF-23) and Klotho levels are considered to be the earliest biochemical abnormality of chronic kidney disease - mineral and bone disease (CKDMBD) syndrome. Moreover, emerging data suggests that the dysregulated FGF-23 and Klotho axis has many effects on the cardiovascular (CV) system and contributes significantly to the increased CV morbidity and mortality rates of CKD patients. This review examines recent evidence on the role of FGF-23 and Klotho in the development and progression of CV complications of uremia namely cardiac hypertrophy, uremic cardiomyopathy, and atherosclerotic and arteriosclerotic vascular lesions. Moreover, the available evidence on their associations with adverse clinical outcomes are summarized. Undoubtedly, more studies are needed to further elucidate the effects of FGF-23 and Klotho on the heart and vessels and to gain insights into their prognostic value as CV risk factors. Finally, large prospective studies are required to test the hypothesis that modification of their levels would have a favourable impact on the unacceptably high mortality rates of these patient populations.

A Novel Uremic Score Reflecting Accumulation of Specific Uremic Toxins More Precisely Predicts One-Year Mortality after Hemodialysis Commencement: A Retrospective Cohort Study.

Uremic toxins (UTs) generally accumulate in patients developing end-stage renal disease (ESRD). Although some kinds of UTs cause early death after starting hemodialysis (HD), it remains unknown whether the degree of excessive accumulation of various UTs is associated with worsening of prognosis. We retrospectively conducted this cohort study consisting of adult patients developing ESRD who initiated HD at the National Center for Global Health and Medicine from 2010 to 2019. We created a new uremic score, which was defined as the aggregate score of the following variables reflecting uremic state: elevated blood urea nitrogen, ß2-microglobulin, and anion gap before starting HD. The primary outcome was early mortality within 1-year after HD commencement. The hazard ratio (HR) and 95% confidence interval (CI) for a one-point increase in uremic score was calculated with Cox proportional hazard models adjusted by baseline conditions. We included 230 participants, 16 of whom experienced the primary outcome of early mortality after HD commencement. Uremic score was significantly associated with the primary outcome (crude HR: 1.91, 95% CI 1.16-3.14; adjusted HR: 4.19, 95% CI 1.79-9.78). Our novel uremic score, reflecting accumulation of specific UTs, more precisely predicts early mortality after HD commencement.

Indoxyl Sulfate, a Uremic Endotheliotoxin.

Chronic kidney disease (CKD) is associated with a high prevalence of cardiovascular diseases. During CKD, the uremic toxin indoxyl sulfate (IS)-derived from tryptophan metabolism-accumulates. IS is involved in the pathophysiology of cardiovascular complications. IS can be described as an endotheliotoxin: IS induces endothelial dysfunction implicated in cardiovascular morbidity and mortality during CKD. In this review, we describe clinical and experimental evidence for IS endothelial toxicity and focus on the various molecular pathways implicated. In patients with CKD, plasma concentrations of IS correlate with cardiovascular events and mortality, with vascular calcification and atherosclerotic markers. Moreover, IS induces a prothrombotic state and impaired neovascularization. IS reduction by AST-120 reverse these abnormalities. In vitro, IS induces endothelial aryl hydrocarbon receptor (AhR) activation and proinflammatory transcription factors as NF-κB or AP-1. IS has a prooxidant effect with reduction of nitric oxide (NO) bioavailability. Finally, IS alters endothelial cell and endothelial progenitor cell migration, regeneration and control vascular smooth muscle cells proliferation. Reducing IS endothelial toxicity appears to be necessary to improve cardiovascular health in CKD patients.

Protein-Bound Uremic Toxins in Hemodialysis Patients Relate to Residual Kidney Function, Are Not Influenced by Convective Transport, and Do Not Relate to Outcome.

Protein-bound uremic toxins (PBUTs) are predominantly excreted by renal tubular secretion and hardly removed by traditional hemodialysis (HD). Accumulation of PBUTs is proposed to contribute to the increased morbidity and mortality of patients with end-stage kidney disease (ESKD). Preserved PBUT excretion in patients with residual kidney function (RKF) and/or increased PBUT clearance with improved dialysis techniques might improve the prognosis of patients with ESKD. The aims of this study are to explore determinants of PBUTs in HD patients, and investigate whether hemodiafiltration (HDF) lowers PBUT plasma concentrations, and whether PBUTs are related to the outcome. Predialysis total plasma concentrations of kynurenine, kynurenic acid, indoxyl sulfate, indole-3-acetic acid, p-cresyl sulfate, p-cresyl glucuronide, and hippuric acid were measured by UHPLC-MS at baseline and after 6 months of follow-up in the first 80 patients participating in the CONvective TRAnsport Study (CONTRAST), a randomized controlled trial that compared the effects of online HDF versus low-flux HD on all-cause mortality and new cardiovascular events. RKF was inversely related to kynurenic acid (p < 0.001), indoxyl sulfate (p = 0.001), indole-3-acetic acid (p = 0.024), p-cresyl glucuronide (p = 0.004) and hippuric acid (p < 0.001) plasma concentrations. Only indoxyl sulfate decreased by 8.0% (-15.3 to 34.6) in patients treated with HDF and increased by 11.9% (-15.4 to 31.9) in HD patients after 6 months of follow-up (HDF vs. HD: p = 0.045). No independent associations were found between PBUT plasma concentrations and either risk of all-cause mortality or new cardiovascular events. In summary, in the current population, RKF is an important determinant of PBUT plasma concentrations in HD patients. The addition of convective transport did not consistently decrease PBUT plasma concentrations and no relation was found between PBUTs and cardiovascular endpoints.

Immune Dysfunction in Uremia 2020.

Cardiovascular disease and infections are major causes for the high incidence of morbidity and mortality of patients with chronic kidney disease. Both complications are directly or indirectly associated with disturbed functions or altered apoptotic rates of polymorphonuclear leukocytes, monocytes, lymphocytes, and dendritic cells. Normal responses of immune cells can be reduced, leading to infectious diseases or pre-activated/primed, giving rise to inflammation and subsequently to cardiovascular disease. This review summarizes the impact of kidney dysfunction on the immune system. Renal failure results in disturbed renal metabolic activities with reduced renin, erythropoietin, and vitamin D production, which adversely affects the immune system. Decreased kidney function also leads to reduced glomerular filtration and the retention of uremic toxins. A large number of uremic toxins with detrimental effects on immune cells have been identified. Besides small water-soluble and protein-bound compounds originating from the intestinal microbiome, several molecules in the middle molecular range, e.g., immunoglobulin light chains, retinol-binding protein, the neuropeptides Met-enkephalin and neuropeptide Y, endothelin-1, and the adipokines leptin and resistin, adversely affect immune cells. Posttranslational modifications such as carbamoylation, advanced glycation products, and oxidative modifications contribute to uremic toxicity. Furthermore, high-density lipoprotein from uremic patients has an altered protein profile and thereby loses its anti-inflammatory properties.

Inflammation and Premature Ageing in Chronic Kidney Disease.

Persistent low-grade inflammation and premature ageing are hallmarks of the uremic phenotype and contribute to impaired health status, reduced quality of life, and premature mortality in chronic kidney disease (CKD). Because there is a huge global burden of disease due to CKD, treatment strategies targeting inflammation and premature ageing in CKD are of particular interest. Several distinct features of the uremic phenotype may represent potential treatment options to attenuate the risk of progression and poor outcome in CKD. The nuclear factor erythroid 2-related factor 2 (NRF2)-kelch-like erythroid cell-derived protein with CNC homology [ECH]-associated protein 1 (KEAP1) signaling pathway, the endocrine phosphate-fibroblast growth factor-23-klotho axis, increased cellular senescence, and impaired mitochondrial biogenesis are currently the most promising candidates, and different pharmaceutical compounds are already under evaluation. If studies in humans show beneficial effects, carefully phenotyped patients with CKD can benefit from them.

Clinical Potential of Targeting Fibroblast Growth Factor-23 and αKlotho in the Treatment of Uremic Cardiomyopathy.

Chronic kidney disease is highly prevalent, affecting 10% to 15% of the adult population worldwide and is associated with increased cardiovascular morbidity and mortality. As chronic kidney disease worsens, a unique cardiovascular phenotype develops characterized by heart muscle disease, increased arterial stiffness, atherosclerosis, and hypertension. Cardiovascular risk is multifaceted, but most cardiovascular deaths in patients with advanced chronic kidney disease are caused by heart failure and sudden cardiac death. While the exact drivers of these deaths are unknown, they are believed to be caused by uremic cardiomyopathy: a specific pattern of myocardial hypertrophy, fibrosis, with both diastolic and systolic dysfunction. Although the pathogenesis of uremic cardiomyopathy is likely to be multifactorial, accumulating evidence suggests increased production of fibroblast growth factor-23 and αKlotho deficiency as potential major drivers of cardiac remodeling in patients with uremic cardiomyopathy. In this article we review the increasing understanding of the physiology and clinical aspects of uremic cardiomyopathy and the rapidly increasing knowledge of the biology of both fibroblast growth factor-23 and αKlotho. Finally, we discuss how dissection of these pathological processes is aiding the development of therapeutic options, including small molecules and antibodies, directly aimed at improving the cardiovascular outcomes of patients with chronic kidney disease and end-stage renal disease.

Uremic memory: the role of acute kidney injury in long-term outcomes.

Most epidemiologic data, thus far, have focused on short-term outcomes of acute kidney injury (AKI). Lo et al. correlate AKI with long-term outcomes. The concept of 'uremic memory' sheds light on the importance of AKI and its permanent imprint. The focus of research should be on prevention of an episode of AKI, when possible.