Evaluating the incidence and risk factors for developing acute tubular necrosis after percutaneous coronary intervention in the management of coronary artery dissection.

BACKGROUND: Coronary artery dissection is managed primarily conservatively with serial imaging or percutaneous coronary intervention (PCI). Exposure to contrast in either modality could potentially result in acute tubular necrosis (ATN). However, no data compares ATN incidence in these management strategies. This study compares the incidence of ATN and associated mortality of PCI and conservative management of coronary artery dissection. METHODS: A retrospective analysis was performed using data from the National Inpatient Sample database, including patients with coronary artery dissection between 2016 through 2020. We analyzed the incidence of ATN and associated mortality of PCI and conservative management of coronary artery dissection. RESULTS: We found that the odds of developing ATN were 22% lower in patients managed with PCI than those managed conservatively. There was no difference in the in-hospital mortality or hospital length of stay between the two groups but the mortality rate in patients with ATN was double that of those who did not develop ATN in both PCI and conservatively managed groups. CONCLUSIONS: The higher incidents of ATN in patients with coronary dissection being managed with conservative measures compared to PCI suggest that the use of CTA may be harmful. Additionally, persons who developed ATN may have higher mortality. Therefore, more studies in the management of coronary artery dissection need to be done which would allow further steps to be taken to reduce this harm.

Clinical manifestations and renal pathology of ethylene glycol.

Ethylene glycol (EG) poisoning is a critical medical emergency often associated with suicide attempts in adults. EG is metabolized by alcohol dehydrogenase, leading to the formation of toxic metabolites that cause metabolic acidosis, renal failure, hypocalcemia, aciduria, and disorders of the central nervous and cardiovascular systems. Calcium oxalate, a metabolite of EG, contributes to acute tubular necrosis. Despite limited reports on human renal pathology, we present a case detailing renal pathology following EG ingestion. A 44-year-old male, admitted due to loss of consciousness, had ingested a lethal dose of EG. Blood tests indicated metabolic acidosis, while urinary examination revealed calcium oxalate crystals. Continuous renal replacement therapy corrected the acidosis; however, nephrogenic diabetes insipidus subsequently developed. A renal biopsy on day 31 revealed calcium oxalate crystal deposition and tubulointerstitial damage. Notably, various stages of crystal deposition, adherence, and degradation were observed. This case underscores the importance of considering EG poisoning in cases of unexplained metabolic acidosis and renal dysfunction, with renal biopsy serving as a valuable diagnostic tool. Understanding the renal effects of EG is essential for timely intervention and effective management of poisoning cases.

Paracetamol overdose causing acute kidney injury without hepatotoxicity: a case report.

BACKGROUND: Paracetamol is a widely used analgesic and antipyretic. Paracetamol-induced hepatotoxicity is well known, but nephrotoxicity without hepatotoxicity is rarely seen. CASE PRESENTATION: We present a case of acute kidney injury without hepatotoxicity in paracetamol overdose. A 15-year-old girl was admitted 48 h after she had taken 10 g of paracetamol. She was complaining of abdominal pain and vomiting. Her blood level of creatinine was 1.20 mg/dL on admission, with a peak at 3.67 mg/dL 3 days later. The liver blood tests and blood paracetamol level were negative. She did not receive N-acetyl cysteine and was treated with intravenous fluid (crystalloid). The ultrasonography of the kidneys was normal. Her renal function returned almost to baseline 7 days after admission. It was concluded that the diagnosis was an acute kidney injury caused by acute tubular necrosis due to paracetamol overdose. CONCLUSION: This case shows that nephrotoxicity can occur without hepatotoxicity in paracetamol overdose.

Mortality prediction and influencing factors for intensive care unit patients with acute tubular necrosis: random survival forest and cox regression analysis.

Background: Patients with acute tubular necrosis (ATN) not only have severe renal failure, but also have many comorbidities, which can be life-threatening and require timely treatment. Identifying the influencing factors of ATN and taking appropriate interventions can effectively shorten the duration of the disease to reduce mortality and improve patient prognosis. Methods: Mortality prediction models were constructed by using the random survival forest (RSF) algorithm and the Cox regression. Next, the performance of both models was assessed by the out-of-bag (OOB) error rate, the integrated brier score, the prediction error curve, and area under the curve (AUC) at 30, 60 and 90 days. Finally, the optimal prediction model was selected and the decision curve analysis and nomogram were established. Results: RSF model was constructed under the optimal combination of parameters (mtry = 10, nodesize = 88). Vasopressors, international normalized ratio (INR)_min, chloride_max, base excess_min, bicarbonate_max, anion gap_min, and metastatic solid tumor were identified as risk factors that had strong influence on mortality in ATN patients. Uni-variate and multivariate regression analyses were used to establish the Cox regression model. Nor-epinephrine, vasopressors, INR_min, severe liver disease, and metastatic solid tumor were identified as important risk factors. The discrimination and calibration ability of both predictive models were demonstrated by the OOB error rate and the integrated brier score. However, the prediction error curve of Cox regression model was consistently lower than that of RSF model, indicating that Cox regression model was more stable and reliable. Then, Cox regression model was also more accurate in predicting mortality of ATN patients based on the AUC at different time points (30, 60 and 90 days). The analysis of decision curve analysis shows that the net benefit range of Cox regression model at different time points is large, indicating that the model has good clinical effectiveness. Finally, a nomogram predicting the risk of death was created based on Cox model. Conclusion: The Cox regression model is superior to the RSF algorithm model in predicting mortality of patients with ATN. Moreover, the model has certain clinical utility, which can provide clinicians with some reference basis in the treatment of ATN and contribute to improve patient prognosis.

Acute kidney tubular injury after ingestion of red yeast rice supplement.

A 47-year-old woman developed severe kidney dysfunction after taking a lipid-lowering supplement, Red Yeast Rice Cholestehelp, for approximately 7 months. The patient developed sudden nausea and had an elevated serum creatinine level of 4.26 mg/dL. A kidney biopsy showed findings consistent with acute tubular necrosis. Kidney dysfunction improved with discontinuation of supplementation, and corticosteroid therapy. Similar kidney involvement has been reported, raising concerns regarding supplements in Japan. An investigation of the nephrotoxic ingredients in the same product batches is currently underway. This report underscores the need for public awareness and warnings of health risk concerns associated with unregulated supplements.

[Prevention of contrast-induced nephropathy]. / Prévention de la néphropathie aux produits de contraste iodés.

Contrast-induced nephropathy (CIN) is a renal complication occurring after the administration of iodinated contrast agents routinely used in medical imaging. CIN causes acute renal failure of varying severity. The pathophysiology of CIN is probably multifactorial: it involves (i) renal vasoconstriction inducing tissue hypoxia, and (ii) a possible direct toxicity of iodine derivatives leading to tubular inflammation and necrosis. Several risk factors are associated with CIN, some related to the procedure itself, others to the patient's co-morbid profile. In particular, the pre-existence of chronic renal failure, dehydration, congestive heart failure, diabetes or hypotension has been associated with an increased risk of CIN, as summarized in the Mehran score. Prevention of CIN relies essentially on adequate i.v. hydration before and after the procedure, and on the administration of the lowest possible volumes of contrast. In patients at high risk of CIN, the use of metformin and non-steroidal anti-inflammatory drugs is contraindicated at the time of contrast medium i.v. injection. In these patients, renal function assessment after 3-7 days post imaging is required.

La néphropathie aux produits de contraste iodés (NPCI) est une complication rénale survenant après l'administration de certains agents de contraste utilisés en imagerie médicale. La NPCI cause une insuffisance rénale aiguë de gravité variable. La physiopathologie de la NPCI est probablement multifactorielle : elle implique (i) une vasoconstriction rénale induisant une hypoxie tissulaire et (ii) une possible toxicité directe des dérivés iodés entraînant inflammation et nécrose tubulaire. Plusieurs facteurs de risque sont associés à la NPCI, liés tantôt à la procédure elle-même, tantôt aux comorbidités du patient. La préexistence d'une insuffisance rénale chronique, d'une déshydratation, d'une insuffisance cardiaque congestive, d'un diabète ou d'une hypotension artérielle a, notamment, été associée à un risque accru de NPCI, tel que résumé dans le score de Mehran. La prévention de la NPCI repose essentiellement sur une hydratation i.v. adéquate avant et après la procédure, ainsi que sur l'administration de volumes de contraste aussi faibles que possible. Chez les patients à haut risque de NPCI, l'utilisation de metformine et/ou d'anti-inflammatoires non stéroïdiens concomitante à l'injection de PCI est formellement contre-indiquée, et la vérification de la fonction rénale à J3-J7 après l'examen radiologique est requise.

Naja nigricincta nigricincta venom, a murine model. Evaluation of skeletal and cardio-myonecrosis, kidney injury and inflammatory response along with neutralisation efficacy by the SAIMR/SAVP - And EchiTAb-Plus-ICP polyvalent antivenoms.

African spitting cobra, Naja nigricincta nigricincta (Zebra snake), envenomation is an important cause of snakebite morbidity and mortality in Namibia. The snake is endemic to central and northern Namibia as well as southern Angola. The venom is mainly cytotoxic, resulting in aggressive dermo-necrosis and often accompanied by severe systemic complications. No specific antivenom exists. Rhabdomyolysis, systemic inflammatory response, haemostatic abnormalities, infective necrotising fasciitis as well as acute kidney failure have been documented. Based on murine models, this study assessed SAVP/SAIMR - and EchiTAb-Plus-ICP polyvalent antivenom neutralisation as well as subdermal necrosis. Additional muscle, cardiac, kidney and lung histology, creatine kinase measurements and post-mortems were performed. An intravenous median lethal dose (LD50) of Naja nigricincta nigricincta venom was determined at 18.4 (CI: 16.3; 20.52) µg and a subdermal lethal dose at 15.3(CI: 12.96; 17.74)µg. The SAIMR/SAVP polyvalent antivenom median effective dose (ED50) was 1.2 ml antivenom/1 mg venom equating to a potency (WHO) of 1 ml antivenom neutralising 0.63 mg venom and approximately 240 ml (24 vials) needed for initial treatment. The ED50 of the EchiTAb-Plus-ICP was 1 ml antivenom/1 mg venom and a potency of 65 mg venom/ml antivenom (3.3 x LD50), estimating 230 ml (23 vials) for treatment. Histology and serology (creatine kinase) evidenced venom induced skeletal myotoxicity, which was not prevented by the antivenoms tested. Cardiac myonecrosis, an inflammatory response, direct venom kidney tubular necrosis and cardio-pulmonary failure were documented.

Renal tubular necrosis associated with anagrelide administration: a case report.

A 62-year-old female patient with essential thrombocythemia experienced rapid renal dysfunction and was subsequently referred to our hospital. Further investigations did not reveal any significant abnormalities except for a slight increase in urinary ß2-microglobulin levels. A renal biopsy was performed to investigate the cause of her renal dysfunction, revealing acute tubular necrosis, interstitial edema, and arteriosclerosis. No significant glomerular lesions were observed. Immunofluorescence staining and electron microscopy showed no abnormalities. She had been using anagrelide for 4 years, and her dosage was increased from 2.0 to 3.0 mg/day 10 months before her initial admission. Her renal function began to deteriorate 2 months after the anagrelide dosage increase. Although 0.625 mg of bisoprolol was initiated for tachycardia 3 months after the anagrelide dosage adjustment, we suspected that the acute tubular necrosis was associated with anagrelide administration. After transitioning from anagrelide to hydroxyurea and discontinuing bisoprolol, her renal function improved. This case suggests the importance of considering anagrelide as a potential cause of renal dysfunction in patients using this medication. Therefore, renal biopsy, combined with a comprehensive medical history, is crucial for evaluating the etiology of renal injury in such cases.

Sandwich-like voltametric immunosensing of interleukin-8 based on ß-cyclodextrin/carbon nanotubes and methylthionine chloride@UIO-66 framework.

The level of interleukin-8 (IL-8) in the body is an effective factor for the early diagnosis of acute tubular necrosis and oral tumor. In this work, a novel sandwich-like voltametric immunosensor (SVS) of IL-8 was constructed by preparing ß-cyclodextrin/carbon nanotube (CD/CNT) to immobilize primary antibody (PAb) of IL-8 and UIO-66-NH2 MOFs structure to immobilize second antibody (SAb) and methylene blue (Mb) probe. In this designed SVS, the prepared CD/CNT nanohybrid with large surface area and conductivity can immobilize PAb via simple host-guest recognition, and UIO-66-NH2 provided an ideal platform to accommodate SAb and a large number of Mb molecules as signal-amplifier. In the existence of target IL-8, the current peak of Mb from the SVS assay increases with the increasement of IL-8 level. Through optimizing and adjusting various factors, a wide linearity (0.001-2.5 ng mL-1) and low analytical limit (0.2 pg mL-1) of IL-8 were realized, so it's expected the developed SVS strategy has significant applications for the detection of IL-8.

Marginal Zone Lymphoma Manifesting as Macrophage Activation Syndrome: A Case Report.

Macrophage activation syndrome (MAS) is a form of secondary hemophagocytic lymphohistiocytosis (HLH) when it occurs in the context of rheumatologic disorders. HLH is a rare and potentially life-threatening syndrome characterized by excessive immune system activation. It is mainly seen in children and can be genetic based or related to infections, malignancies, rheumatologic disorders, or immunodeficiency syndromes. MAS can present with nonspecific symptoms, leading to a delay in diagnosis. This report describes a case of a 64-year-old female with marginal zone lymphoma and systemic lupus erythematosus who presented with a purpuric rash and acute kidney injury. She underwent a kidney biopsy and was diagnosed with MAS. This case highlights the importance of promptly recognizing MAS's symptoms and signs, allowing timely diagnosis and early therapeutic intervention. This potentially fatal condition tends to respond well to rapid treatment initiation with corticosteroids and to address the underlying condition.

Galectin-3 and Autophagy in Renal Acute Tubular Necrosis.

Acute kidney injury (AKI) is a public health burden with increasing morbidity and mortality rates and health care costs. Acute tubular necrosis (ATN) is the most common cause of AKI. Cisplatin (CIS) is a platinum-based chemotherapeutic agent used in the treatment of a wide variety of malignancies such as lung, breast, ovary, testis, bladder, cervix, and head and neck cancers. Autophagy plays an important role in AKI. Galectin-3 (Gal-3) is significantly increased in renal tubules in AKI; however, its role in autophagy is not well understood. Male C57B6/J and B6.Cg-Lgals3 /J Gal-3 knockout (KO) mice were used to induce AKI using a CIS mouse model of ATN. Renal Gal-3 and autophagy proteins' expression were measured using standard histologic, immunofluorescent, and enzyme-linked immunosorbent assay techniques. The data were presented as the mean ± S.E. Statistically significant differences (p < 0.05) were calculated between experimental groups and corresponding control groups by one-way analysis of variance. There was a significant increase in renal concentrations of Gal-3 in the Gal-3 wild-type CIS-treated mice when compared with sham control mice. There were significantly higher concentrations of renal LC3B, ATG13, Ulk-1, Beclin, ATG5, ATG12, ATG9A, and p-AMPK in the CIS-treated Gal-3 KO mice than in the Gal-3 wild-type CIS-treated mice. Further, there were significantly higher concentrations of mTOR, p- NF-κB, beta-catenin, and p62 in the kidneys of the Gal-3 wild-type CIS-treated mice than in the Gal-3 KO CIS-treated mice. Our findings affirm the connection between Gal-3 and autophagy, revealing its central role as a connector with prosurvival signaling proteins. Gal-3 plays a pivotal role in orchestrating cellular responses by interacting with prosurvival signal pathways and engaging with autophagy proteins. Notably, our observations highlight that the absence of Gal-3 can enhance autophagy in CIS-induced ATN.

Study of prevalence, risk factors for acute kidney injury, and mortality in liver cirrhosis patients.

INTRODUCTION: Acute kidney injury (AKI) occurs frequently in patients with end-stage liver disease and cirrhosis and is associated with increased short-term mortality. This study aims to study the prevalence and risk factors associated with AKI development and mortality in cirrhosis of liver patients. METHODOLOGY: In the current prospective study, hospitalized patients with liver cirrhosis from October 2021 to March 2023 were recruited. Demographic, clinical, and laboratory data were collected, which included, the etiology of cirrhosis, comorbidities, severity of liver disease, and relevant biochemical parameters. The patient was followed up for 90 days to record the clinical outcome. The statistical software SPSS was utilized to conduct the analysis. RESULTS: Of 364 liver cirrhosis patients, 25.2% (n, 92) had AKI and belonged to an average age of 51.54 ± 11.82 years. The majority of individuals in the study were males (90.4%), and alcohol (63.4%) was the most common etiology of liver cirrhosis. The present study showed that higher level of direct bilirubin (p = 0.011) and MELD score (p = 0.0001) were identified as significant risk factors for AKI development in patients with liver cirrhosis. Regarding mortality, the significant risk factors were the presence of AKI (p = 0.045) and MELD score (p = 0.025). Among AKI patients, 90-day mortality rates were higher in patients with acute tubular necrosis (p value = 0.010) and stage 3 AKI (p value = 0.001). CONCLUSION: AKI is common in cirrhosis of liver patients. Elevated levels of direct bilirubin and MELD score emerged as significant factors associated with AKI development. Furthermore, AKI and MELD scores were identified as independent risk factors for mortality at both 30 and 90 days. Survival rates were influenced by both the type and stage of AKI; AKI stage 3 and ATN patients had significantly higher mortality rate. Early AKI detection and management are crucial for reducing mortality risk in liver cirrhosis patients.

A Case of Steroid-Responsive Acute Tubular Injury of Unknown Trigger: A Case Report.

Acute tubular necrosis (ATN) is a serious medical condition characterized by the rapid destruction of renal tubular epithelial cells, resulting in acute kidney injury, given its multifactorial etiologies, which can include nephrotoxic agents, ischemic insults, hypovolemia, and sepsis. We report the case of a young male patient who presented with recurrent worsening kidney function with bland sediment that was confirmed with multiple kidney biopsies as recurrent attacks of ATN of unclear etiology, which did not respond to supportive measures but did respond to steroids.

Assessment of Acute Kidney Injury using MRI.

There has been growing interest in using quantitative magnetic resonance imaging (MRI) to describe and understand the pathophysiology of acute kidney injury (AKI). The ability to assess kidney blood flow, perfusion, oxygenation, and changes in tissue microstructure at repeated timepoints is hugely appealing, as this offers new possibilities to describe nature and severity of AKI, track the time-course to recovery or progression to chronic kidney disease (CKD), and may ultimately provide a method to noninvasively assess response to new therapies. This could have significant clinical implications considering that AKI is common (affecting more than 13 million people globally every year), harmful (associated with short and long-term morbidity and mortality), and currently lacks specific treatments. However, this is also a challenging area to study. After the kidney has been affected by an initial insult that leads to AKI, complex coexisting processes ensue, which may recover or can progress to CKD. There are various preclinical models of AKI (from which most of our current understanding derives), and these differ from each other but more importantly from clinical AKI. These aspects are fundamental to interpreting the results of the different AKI studies in which renal MRI has been used, which encompass different settings of AKI and a variety of MRI measures acquired at different timepoints. This review aims to provide a comprehensive description and interpretation of current studies (both preclinical and clinical) in which MRI has been used to assess AKI, and discuss future directions in the field. LEVEL OF EVIDENCE: 1 TECHNICAL EFFICACY: Stage 3.

Successful Treatment with Steroids in a Patient with Vanishing Bile Duct Syndrome and Acute Tubular Necrosis.

Vanishing bile duct syndrome (VBDS) is a rare but potentially serious cholestatic liver disease caused by various etiologies, including drugs. We herein report a complicated case of VBDS with acute tubular necrosis (ATN) that improved significantly with steroid treatment. An Asian man in his 30s was admitted with the acute onset of severe jaundice and a decline in the renal function. Although initial treatment with ursodeoxycholic acid did not reduce jaundice or renal dysfunction, steroid treatment remarkably improved the VBDS and ATN to within the respective normal ranges. Steroid treatment can be considered in cases of VBDS that appear to have an immune-mediated cause.

Functional MRI evaluation of blood oxygen dependent (BOLD) in renal allograft dysfunction: a prospective study.

BACKGROUND: Blood oxygen level dependent-magnetic resonance imaging (BOLD-MRI) is a non-invasive functional imaging technique that can be used to assess renal allograft dysfunction. PURPOSE: To evaluate the diagnostic performance of BOLD-MRI using a 3-T scanner in discriminating causes of renal allograft dysfunction in the post-transplant period. MATERIAL AND METHODS: This prospective study was conducted on 112 live donor-renal allograft recipients: 53 with normal graft function, as controls; 18 with biopsy-proven acute rejection (AR); and 41 with biopsy-proven acute tubular necrosis (ATN). Multiple fast-field echo sequences were performed to obtain T2*-weighted images. Cortical R2* (CR2*) level, medullary R2* (MR2*) level, and medullary over cortical R2* ratio (MCR) were measured in all participants. RESULTS: The mean MR2* level was significantly lower in the AR group (20.8 ± 2.8/s) compared to the normal group (24 ± 2.4/s, P <0.001) and ATN group (27.4 ± 1.7/s, P <0.001). The MCR was higher in ATN group (1.47 ± 0.18) compared to the AR group (1.18 ± 0.17) and normal functioning group (1.34 ± 0.2). Both MR2* (area under the curve [AUC] = 0.837, P <0.001) and MCR (AUC = 0.727, P = 0.003) can accurately discriminate ATN from AR, however CR2* (AUC = 0.590, P = 0.237) showed no significant difference between both groups. CONCLUSION: In early post-transplant renal dysfunction, BOLD-MRI is a valuable non-invasive diagnostic technique that can differentiate between AR and ATN by measuring changes in intra-renal tissue oxygenation.

Pathophysiology of Red Blood Cell Trapping in Ischemic Acute Kidney Injury.

Red blood cell (RBC) trapping describes the accumulation of RBCs in the microvasculature of the kidney outer medulla that occurs following ischemic acute kidney injury (AKI). Despite its prominence in human kidneys following AKI, as well as evidence from experimental models demonstrating that the severity of RBC trapping is directly correlated with renal recovery, to date, RBC trapping has not been a primary focus in understanding the pathogenesis of ischemic kidney injury. New evidence from rodent models suggests that RBC trapping is responsible for much of the tubular injury occurring in the initial hours after kidney reperfusion from ischemia. This early injury appears to result from RBC cytotoxicity and closely reflects the injury profile observed in human kidneys, including sloughing of the medullary tubules and the formation of heme casts in the distal tubules. In this review, we discuss what is currently known about RBC trapping. We conclude that RBC trapping is likely avoidable. The primary causes of RBC trapping are thought to include rheologic alterations, blood coagulation, tubular cell swelling, and increased vascular permeability; however, new data indicate that a mismatch in blood flow between the cortex and medulla where medullary perfusion is maintained during cortical ischemia is also likely critical. The mechanism(s) by which RBC trapping contributes to renal functional decline require more investigation. We propose a renewed focus on the mechanisms mediating RBC trapping, and RBC trapping-associated injury is likely to provide important knowledge for improving AKI outcomes. © 2024 American Physiological Society. Compr Physiol 14:5325-5343, 2024.

Clinical and pathological characteristics of diquat poisoning-related acute kidney injury.

Objectives: Diquat has replaced paraquat in agricultural areas as a herbicide but has led to extensive poisoning. Unlike paraquat, which targets the lungs, diquat primarily targets the kidneys. Autopsies and animal experiments suggest that interstitial kidney damage is the most critical renal lesion. Diquat is a nonselective chemical widely used for terrestrial and aquatic plants after the ban on paraquat. Although diquat is known to affect the kidneys mainly, no study has reported renal biopsy in patients with diquat poisoning.Methods: We investigated the histopathologic feature in a young man with diquat poisoning who developed acute kidney injury by renal biopsy.Results: Autopsy and animal experiments suggest that interstitial kidney inflammation is the most critical renal lesion. Surprisingly, our results showed that lipid degeneration and acute tubular injury with limited interstitial inflammation were the dominant histologic findings in this patient. Conclusions: Based on a renal biopsy, this was the first study describing the characteristics of the kidney affected by diquat poisoning. Our findings might provide information for managing patients who develop AKI due to diquat poisoning.

The Role of Oxidative Stress in Kidney Injury.

Acute kidney injury and chronic kidney disease are among the most common non-communicable diseases in the developed world, with increasing prevalence. Patients with acute kidney injury are at an increased risk of developing chronic kidney disease. One of kidney injury's most common clinical sequelae is increased cardiovascular morbidity and mortality. In recent years, new insights into the pathophysiology of renal damage have been made. Oxidative stress is the imbalance favoring the increased generation of ROS and/or reduced body's innate antioxidant defense mechanisms and is of pivotal importance, not only in the development and progression of kidney disease but also in understanding the enhanced cardiovascular risk in these patients. This article summarizes and emphasizes the role of oxidative stress in acute kidney injury, various forms of chronic kidney disease, and also in patients on renal replacement therapy (hemodialysis, peritoneal dialysis, and after kidney transplant). Additionally, the role of oxidative stress in the development of drug-related nephrotoxicity and also in the development after exposure to various environmental and occupational pollutants is presented.

Extravasation of Blood and Blood Toxicity Drives Tubular Injury from RBC Trapping in Ischemic AKI.

Red blood cell (RBC) trapping is common in ischemic acute kidney injury (AKI) and presents as densely packed RBCs that accumulate within and engorge the kidney medullary circulation. In this study, we tested the hypothesis that "RBC trapping directly promotes tubular injury independent of extending ischemia time." Studies were performed on rats. Red blood cell congestion and tubular injury were compared between renal arterial clamping, venous clamping, and venous clamping of blood-free kidneys. Vessels were occluded for either 15 or 45 min with and without reperfusion. We found that RBC trapping in the medullary capillaries occurred rapidly following reperfusion from renal arterial clamping and that this was associated with extravasation of blood from congested vessels, uptake of blood proteins by the tubules, and marked tubular injury. To determine if this injury was due to blood toxicity or an extension of ischemia time, we compared renal venous and arterial clamping without reperfusion. Venous clamping resulted in RBC trapping and marked tubular injury within 45 min of ischemia. Conversely, despite the same ischemia time, RBC trapping and tubular injury were minimal following arterial clamping without reperfusion. Confirming the role of blood toward tubular injury, injury was markedly reduced in blood-free kidneys with venous clamping. Our data demonstrate that RBC trapping results in the rapid extravasation and uptake of blood components by tubular cells, causing toxic tubular injury. Tubular toxicity from extravasation of blood following RBC trapping appears to be a major component of tubular injury in ischemic AKI, which has not previously been recognized.