Cardiac Surgery-Associated Acute Kidney Injury.

AKI is a common and serious complication of cardiac surgery that has a significant impact on patient morbidity and mortality. The Kidney Disease Improving Global Outcomes definition of AKI is widely used to classify and identify AKI associated with cardiac surgery (cardiac surgery-associated AKI [CSA-AKI]) on the basis of changes in serum creatinine and/or urine output. There are various preoperative, intraoperative, and postoperative risk factors for the development of CSA-AKI which should be recognized and addressed as early as possible to expedite its diagnosis, reduce its occurrence, and prevent or ameliorate its devastating complications. Crucial issues are the inaccuracy of serum creatinine as a surrogate parameter of kidney function in the perioperative setting of cardiothoracic surgery and the necessity to discover more representative markers of the pathophysiology of AKI. However, except for the tissue inhibitor of metalloproteinase-2 and insulin-like growth factor binding protein 7 ratio, other diagnostic biomarkers with an acceptable sensitivity and specificity are still lacking. This article provides a comprehensive review of various aspects of CSA-AKI, including pathogenesis, risk factors, diagnosis, biomarkers, classification, prevention, and treatment management.

Short-, Mid-, and Long-term Outcomes after Deceased Donor Kidney Transplantation in Patients with Acute Kidney Injury.

BACKGROUND: Acute kidney injury (AKI) is a common complication in hospitalized patients and may occur in potential kidney donors. Observational studies have suggested that kidney transplantation in patients with AKI is feasible and safe, but no systematic evaluation has been performed. METHODS: We performed a systematic review and meta-analysis to evaluate the outcomes of kidney transplantation in patients with AKI. We searched MEDLINE, EMBASE, Cochrane, Google Scholar, and other databases for studies reporting outcomes of donor kidneys with AKI. We included single-center, multicenter, and registry-based studies and analyzed them according to the definition and severity of AKI. Endpoints were primary and delayed graft function (PNF, DGF), length of hospital stay, rejection, graft function, patient and graft survival at one, three, five, and eight to ten years after transplantation. This study was registered in PROSPERO, number CRD42021260088. RESULTS: We identified 33 single-center, 4 multicenter, and 7 registry studies with more than 100,000 patients published between 2005 and 2022. Recipients from donors with AKI had a higher risk of delayed graft function (RR 1.51, 95% CI 1.35-1.68). Graft function at discharge was worse in the AKI group (MDCrea (95%CI): 0.96 mg/dl (0.36-1.56 I2=96%), MDGFR (95%CI): -8.88 ml/min1.73 m2 (-15.32 - -2.44 I2=93%)), but improved thereafter and was similar in both groups at 3 months after transplantation (MDCrea (95%CI): -0.05 mg/dl (-0.18-0.07 I2=0%), MDGFR (95%CI): -1.83 ml/min1.73 m2 (-5.29 - 1.63 I2=91%)). PNF and patient and graft survival were simila at one, three, five, and eight to ten years after transplantation. There were no differences in rejections regardless of AKI definition and severity. CONCLUSION: Transplantation of kidneys with AKI is associated with satisfactory short- and long-term outcomes and should be pursued to increase the donor pool.

Association of metabolic syndrome and chronic kidney disease.

The prevalence of kidney disease is increasing rapidly worldwide, reflecting rising rates of obesity, diabetes, and associated metabolic syndrome (MetS). Chronic kidney disease and related comorbidities such as obesity, diabetes, and hypertension place a significant financial burden on healthcare systems. Despite the widespread use of RAAS inhibitors, intensive blood pressure and glycemic control, and newer therapeutic options consisting of sodium/glucose cotransporter-2 (SGLT-2) inhibitors or glucagon-like peptide-1 (GLP-1) receptor agonists, a significant risk of progression to end-stage renal disease remains in the high-risk obese and diabetic population. The MetS is a cluster of cardiovascular risk factors that adversely affect the development and progression of chronic kidney failure. According to the criteria of the World Health Organization, it is defined by visceral adiposity, impaired glucose tolerance or insulin resistance, atherogenic dyslipidemia, raised blood pressure, and microalbuminuria with a albumin-to-creatinine ratio ≥30 mg/g. At molecular level MetS is marked by a proinflammatory state and increased oxidative stress leading to various pathophysiological changes causing endothelial dysfunction and a hypercoagulable state. Because the kidney is a highly vascularized organ, it is especially susceptible for those microvascular changes. Therefore, the MetS and its individual components are associated with the premature development, acceleration, and progression of chronic kidney disease. Therefore, it is becoming increasingly important to elucidate the underlying mechanisms of MetS-associated chronic kidney disease in order to develop new strategies for preventing and slowing the progression of renal disease. In this review, we will elucidate (i) the renal structural, hemodynamic, and metabolic changes that occur in obesity and obesity-related kidney injury; (ii) the clinicopathological characteristics of obesity-related kidney injury, primarily focusing on obesity-associated glomerulopathy; (iii) the potential additional factors or predisposing factors that may turn patients more susceptible to renal structural or functional compensatory failure and subsequent injury.

Factors Affecting Performance of DNA Methylation as a Potential Biomarker in Ascites for Peritonitis and Peritoneal Carcinomatosis.

BACKGROUND AND AIMS: Despite limited sensitivity, the gold standard for the diagnosis of malignant cells in ascites is still cytology. The aim of this prospective proof-of-principle study was to evaluate DNA methylation as a molecular tool for the differential diagnosis of benign and malignant ascites. METHODS: A cohort of 79 patients with malignant and non-malignant ascites was prospectively enrolled. Ascites was assessed by cytopathological and laboratory examination. Cell pellets obtained by centrifugation were analyzed for differences in DNA methylation of of long interspersed nuclear element-1 (LINE-1) and microRNA-137. Quantitative determination of methylation in bisulfite-converted DNA was performed by pyrosequencing. In a subsequent stage, we compared our data to previously published data in the field following systematic review of the literature. RESULTS: Methylation status of studied LINE-1 and microRNA-137 could be reliably detected in all samples. Systematic evaluation revealed reliable reproducibility with satisfactory short- and long-term stability against degradation. Ascites from patients with a malignancy had a significantly higher methylation level of microRNA-137 compared with patients without tumor disease, whereas patients with peritonitis had significantly decreased methylation of microRNA-137. In contrast, differences in the measurement of the methylation status of LINE-1 could only be detected between patients with portal hypertension and a combination of malignant and infectious ascites. Inflammatory cells reflecting peritonitis correlated to DNA methylation changes. CONCLUSIONS: Analysis of DNA methylation in ascites is technically feasible, well reproducible and may lead to identification of potential biomarkers for peritoneal carcinomatosis and other conditions. Inflammatory cells due to peritonitis may also be associated with DNA methylation changes and need to be considered in future studies. Profiling studied under standardized conditions will be needed to identify the appropriate biomarkers for differential diagnosis of ascites.

Pr-AKI: Acute Kidney Injury in Pregnancy - Etiology, Diagnostic Workup, Management.

Despite significant improvements in inpatient and outpatient management, pregnancy-related acute kidney injury (Pr-AKI) remains an important risk factor for early and late maternal and fetal morbidity and mortality. There is a discrepancy between the incidence of Pr-AKI in developing and in developed countries, with the former experiencing a decrease and the latter an increase in Pr-AKI in recent decades. Whereas septic and hemorrhagic complications predominated in the past, nowadays hypertensive disorders and thrombotic microangiopathy are the leading causes of Pr-AKI. Modern lifestyles and the availability and widespread use of in-vitro fertilization techniques in industrialized countries have allowed more women of advanced age to become pregnant. This has led to a rise in the percentage of high-risk pregnancies due to the disorders and comorbidities inherent to or accompanying aging, such as diabetes, arterial hypertension and preexisting chronic kidney disease. Last but not least, the heterogeneity of symptoms, the often overlapping clinical and laboratory characteristics and the pathophysiological changes related to pregnancy make the diagnosis and management of Pr-AKI a difficult and challenging task for the treating physician. In addition to general supportive management strategies such as volume substitution, blood pressure control, prevention of seizures or immediate delivery, each disease entity requires a specific therapy to reduce maternal and fetal complications. In this review, we used the current literature to provide a summary of the physiologic and pathophysiologic changes in renal physiology which occur during pregnancy. In the second part, we present common and rare disorders which lead to Pr-AKI and provide an overview of the available treatment options.

[Chronic kidney injury in patients with liver diseases - Reappraising pathophysiology and treatment options]. / Ursachen der chronischen Nierenschädigung in Patienten mit Lebererkrankungen ­ Pathophysiologie und Therapiemöglichkeiten.

Acute and chronic kidney disease concurs commonly with liver disease and is associated with a wide array of complications including dialysis dependency and increased mortality. Patients with liver disease or liver cirrhosis show a higher prevalence of chronic kidney disease. This is attributed to concomitant comorbidities, such as metabolic syndrome, chronic inflammation, hypercoagulability, hyperfibrinolysis, diabetes mellitus and dyslipidaemias. But chronic progressive kidney disease is not always due to hepatorenal syndrome. Beyond that, other diseases or disease entities should be considered. Among them are diabetic nephropathy, secondary IgA nephropathy, hepatitis C -associated membranoproliferative Glomerulonephritis (MPGN) and hepatitis B-associated membranous nephropathy.Coexisting diseases, similar underlying pathophysiologic mechanisms, or simultaneously concurring pathophysiological processes and overlapping clinical manifestations, impede the etiologic diagnosis and corresponding treatment of chronic kidney disease in the setting of chronic liver disease. In this review, we focus on common and rare pathologies, which can lead to chronic kidney disease in this particular patient group and try to summarize the most recent therapeutic modalities.

[Acute kidney injury following acute pancreatitis (AP-AKI): Definition, Pathophysiology, Diagnosis and Therapy]. / Pankreatitisbedingte akute Nierenschädigung (AP-AKI): Definition, Pathophysiologie, Diagnostik und Therapie.

Acute pancreatitis (AP) is the most frequent gastrointestinal cause for hospitalization and one of the leading causes of in-hospital deaths. Severe acute pancreatitis is often associated with multiorgan failure and especially with acute kidney injury (AKI). AKI can develop early or late in the course of the disease and is a strong determinator of outcome. The mortality in the case of dialysis-dependent AKI and acute pancreatitis raises exponentially in the affected patients. AP-induced AKI (AP-AKI) shows many similarities but also distinct differences to other causes of AKI occurring in the intensive care unit setting. The knowledge of the exact pathophysiology can help to adjust, control and improve therapeutic approaches to the disease. Unfortunately, there are only a few studies dealing with AP and AKI.In this review, we discuss recent data about pathogenesis, causes and management of AP-AKI in patients with severe acute pancreatitis and exploit in this regard the diagnostic and prognostic potential of respective newer serum and urine markers.

[Paradigm shift in understanding Acute kidney injury in patients with chronic liver disease: From pathophysiology to defining disease entities]. / Paradigmenwechsel im Verständnis der akuten Nierenschädigung bei chronischer Leberinsuffizienz: Von der Pathophysiologie zur Definition von Krankheitsentitäten.

The hepatorenal syndrome (HRS) is only a part of the wide spectrum of renal injury in patients with end-stage liver cirrhosis. Besides that, the advanced liver disease itself, or its underlying causes, as well as comorbidities, like diabetes mellitus, adiposity and arterial hypertension, can directly cause parenchymal renal insults (bile acid nephropathy, ischemic tubular injury, diabetic/hypertensive nephropathy, hepatitis B- and C-associated glomerulonephritis etc.). This kind of kidney injury is collectively described as non-hepatorenal syndrome AKI (non-HRS AKI. Beyond that, accumulating evidence highlights the role of systemic inflammation as an important common factor in the pathogenesis of decompensated liver cirrhosis, acute in chronic liver failure (ACLF) and renal dysfunction.In this review, we discuss recent data about definition, classification and pathophysiology of HRS, HRS-AKI and Non-HRS-AKI and exploit in this regard the diagnostic and prognostic potential of respective newer serum and urine markers.

Perioperative Therapy of Oesophagogastric Adenocarcinoma: Mainstay and Future Directions.

Perioperative chemotherapy improves overall survival in patients with oesophagogastric adenocarcinoma (OAC) and locoregional disease. The mainstay of perioperative chemotherapy in these patients is a platinum/fluoropyrimidine combination. The phase III FLOT4 trial has shown that the FLOT triplet regimen (oxaliplatin, infusional 5-FU, and docetaxel) improves the outcome of patients with OAC and locoregional disease as compared to the ECF triplet (epirubicin, cisplatin, and infusional 5-FU). Targeted therapies have currently no role in the perioperative setting for the treatment of patients with OAC. For patients with oligometastatic disease, upfront gastrectomy followed by chemotherapy did not show any survival benefit compared with chemotherapy alone and thus should be discouraged. Whether surgery should be offered to patients with metastatic OAC achieving a systemic control after upfront chemotherapy is under scrutiny in the phase III FLOT5/Renaissance trial. After neoadjuvant treatment, lymph node status but not pathologic tumor response is an independent factor in the prediction of overall survival. Growing evidence suggests that perioperative chemotherapy may be associated with an increased mortality risk in patients with microsatellite instable (MSI)/mismatch repair-deficient (MMRD) adenocarcinoma, thus validating poor responsiveness to chemotherapy in MSI patients with locoregional disease.