Vitamin C Deficiency Causes Cell Type-Specific Epigenetic Reprogramming and Acute Tubular Necrosis in a Mouse Model.

BACKGROUND: Vitamin C deficiency is found in patients with variable kidney diseases. However, the role of vitamin C as an epigenetic regulator in renal homeostasis and pathogenesis remains largely unknown. METHODS: We showed that vitamin C deficiency leads to acute tubular necrosis (ATN) using a vitamin C-deficient mouse model (Gulo knock-out). DNA/RNA epigenetic modifications and injured S3 proximal tubule cells were identified in the vitamin C-deficient kidneys using whole-genome bisulfite sequencing, methylated RNA immunoprecipitation sequencing, and single-cell RNA sequencing. RESULTS: Integrated evidence suggested that epigenetic modifications affected the proximal tubule cells and fenestrated endothelial cells, leading to tubule injury and hypoxia through transcriptional regulation. Strikingly, loss of DNA hydroxymethylation and DNA hypermethylation in vitamin C-deficient kidneys preceded the histologic sign of tubule necrosis, indicating the causality of vitamin C-induced epigenetic modification in ATN. Consistently, prophylactic supplementation of an oxidation-resistant vitamin C derivative, ascorbyl phosphate magnesium, promoted DNA demethylation and prevented the progression of cisplatin-induced ATN. CONCLUSIONS: Vitamin C played a critical role in renal homeostasis and pathogenesis in a mouse model, suggesting vitamin supplementation may be an approach to lower the risk of kidney injury.

Pathological Features of Recovery or Progression in Acute Tubular Necrosis: Single Centre Study.

Acute tubular necrosis (ATN) is the most important and frequent cause of acute kidney injury (AKI). Controversy exists concerning the role of renal biopsy in the evaluation of ATN prognosis. We aim in our study to evaluate the role of renal biopsy for the detection of recovery and progression and rate of recovery of ATN. The study was designed to include all biopsies with the diagnosis in ATN in adults >21-year-old, from January 2016 to December 2018. Biopsies were recruited retrospectively and were reviewed by three pathologists and quantitated. Four histological ATN features were evaluated. Flattening cells, distension or dilatation, debris, and vacuolation and for each a score were attributed as follows: 0 = less than 5% of section, 1 = 6%-25%, 2 = 26%-50%, 3 = >50%. Thirty-five patients with 35 renal biopsies were analyzed. Flattening was seen <5% in nine patients, 6%-25% in 15 patients, 26%-50% in six patients. and >50% in five patients. Dilatation was seen <5% in 11 patient, 6%-25% in 10 patients, 26%-50% seen in six patients, and >50% in eight patients. The presence of debris was seen in <5% in 12 patients, 6%-25% in 12 patients, 26%-50% seen in six patients, and >50% seen in five patient. Vacuolation was seen in 5% in eight patients, 6%-25% in 14 patients, 26%-50% in seven patients, and >50% in six patients. It was found that flattening <5% and dilatation <5% and dilatation >50% in renal biopsy are the good indicators for recovery and good prognosis of cases of ATN, in addition debris <5% and >50% and vacuolation <5% are also good indicators for recovery and good prognosis of cases of ATN. On the other hand, flattening from 6% to 25% and from 26% to 50%, dilatation from 6% to 25%, debris from 26% to 50% and vacuolation >50% are also indicators for delayed recovery and poor prognosis of cases of ATN. Renal biopsy in AKI with the diagnosis of ATN with scoring system of flattening, dilatation, debris, and vacuolation can point to indication of recovery or progression of these cases.

Renal hemosiderosis presenting with acute kidney Injury and macroscopic hematuria in Immunoglobulin A nephropathy: a case report.

BACKGROUND: Macroscopic hematuria-associated acute kidney injury (AKI) is a well-known complication of immunoglobulin A (IgA) nephropathy. In such cases, intratubular obstruction by red blood cell (RBC) casts and acute tubular necrosis are mainly observed pathologically. Herein, we report the case of a patient with IgA nephropathy presenting with AKI following an episode of macrohematuria. The patient presented with severe renal tubular hemosiderosis and acute tubular necrosis and without any obvious obstructive RBC casts. CASE PRESENTATION: A 68-year-old woman, who was diagnosed with IgA nephropathy on renal biopsy 6 years ago, was admitted to our hospital after an episode of macroscopic glomerular hematuria and AKI following upper respiratory tract infection. Renal biopsy showed mesangial proliferation of the glomeruli, including crescent formation in 17 % of the glomeruli, and acute tubular necrosis without obvious hemorrhage or obstructive RBC casts. The application of Perls' Prussian blue stain showed hemosiderin deposition in the renal proximal tubular cells. Immunofluorescence showed granular mesangial deposits of IgA and C3. Based on these findings, she was diagnosed with acute tubular necrosis with a concurrent IgA nephropathy flare-up. Moreover, direct tubular injury by heme and iron was considered to be the cause of AKI. She was treated with intravenous pulse methylprednisolone followed by oral prednisolone. Thereafter, the gross hematuria gradually faded, and her serum creatinine levels decreased. CONCLUSIONS: IgA nephropathy presenting with acute kidney injury accompanied by macrohematuria may cause renal hemosiderosis and acute tubular necrosis without obstructive RBC casts. Hemosiderosis may be a useful indicator for determining the pathophysiology of macroscopic hematuria-associated AKI. However, renal hemosiderosis may remain undiagnosed. Thus, Perls' Prussian blue iron staining should be more widely used in patients presenting with hematuria.

Lansoprazole promotes cisplatin-induced acute kidney injury via enhancing tubular necroptosis.

Acute kidney injury (AKI) is the main obstacle that limits the use of cisplatin in cancer treatment. Proton pump inhibitors (PPIs), the most commonly used class of medications for gastrointestinal complications in cancer patients, have been reported to cause adverse renal events. However, the effect of PPIs on cisplatin-induced AKI remains unclear. Herein, the effect and mechanism of lansoprazole (LPZ), one of the most frequently prescribed PPIs, on cisplatin-induced AKI were investigated in vivo and in vitro. C57BL/6 mice received a single intraperitoneal (i.p.) injection of cisplatin (18 mg/kg) to induce AKI, and LPZ (12.5 or 25 mg/kg) was administered 2 hours prior to cisplatin administration and then once daily for another 2 days via i.p. injection. The results showed that LPZ significantly aggravated the tubular damage and further increased the elevated levels of serum creatinine and blood urea nitrogen induced by cisplatin. However, LPZ did not enhance cisplatin-induced tubular apoptosis, as evidenced by a lack of significant change in mRNA and protein expression of Bax/Bcl-2 ratio and TUNEL staining. Notably, LPZ increased the number of necrotic renal tubular cells compared to that by cisplatin treatment alone, which was further confirmed by the elevated necroptosis-associated protein expression of RIPK1, p-RIPK3 and p-MLKL. Furthermore, LPZ deteriorated cisplatin-induced inflammation, as revealed by the increased mRNA expression of pro-inflammatory factors including, NLRP3, IL-1ß, TNF-α and caspase 1, as well as neutrophil infiltration. Consistently, in in vitro study, LPZ increased HK-2 cell death and enhanced inflammation, compared with cisplatin treatment alone. Collectively, our results demonstrate that LPZ aggravates cisplatin-induced AKI, and necroptosis may be involved in the exacerbation of kidney damage.

Outcomes of Delayed Graft Function in Kidney Transplant Recipients Stratified by Histologic Biopsy Findings.

Delayed graft function (DGF) after kidney transplantation is associated with an increased risk of graft failure. We studied the histologic findings among adult kidney transplant recipients transplanted between January 2000 and June 2015 who had DGF and had a kidney biopsy within 14 days of transplant. Death censored graft failure (DCGF) and death at 1 and 3 years after transplant were examined. A total of 269 transplant recipients fulfilled our selection criteria, of which 152 (56.51%) had acute tubular necrosis (ATN), 44 (16.4%) had acute rejection (AR), mainly T-cell mediated rejection (n = 31), 35 (13%) had ATN with AR (mainly T-cell mediated rejection, n = 26), and 38 (14.1%) had other pathology. Compared with those with ATN alone, kidney transplant recipients with AR alone had a significantly higher risk of DCGF at 1 year post transplant (adjusted hazard ratio = 3.70; 95% confidence interval 1.5-9.5; P = .006). Those with AR alone had an increased risk of DCGF at 3 years post transplant (hazard ratio = 3.10; 95% confidence interval 1.3-8.5; P = .01) in crude analyses. There was no association between DGF etiology and mortality. Early renal biopsy can be used to distinguish AR, which has protocolized treatments, from other etiologies. This could potentially alter allograft survival within 1 year of transplant complicated by DGF.

[Therapeutics for acute tubular necrosis in 2020]. / Prise en charge de la nécrose tubulaire aiguë en 2020.

Acute kidney injury is a major cause of in-hospital morbidity and mortality because of the serious nature of the underlying illnesses and the high incidence of complications. The two major causes of acute kidney injury that occur in the hospital are prerenal disease and acute tubular necrosis. Acute tubular necrosis has a histological definition, even if a kidney biopsy is rarely performed. Kidney injuries occurring during acute tubular necrosis are underlined by different pathophysiological mechanisms that emphasize the role of hypoxia on the tubular cells such as apoptosis, cytoskeleton disruption, mitochondrial function and the inflammation mediated by innate immune cells. The microcirculation and the endothelial cells are also the targets of hypoxia-mediated impairment. Repair mechanisms are sometimes inadequate because of pro-fibrotic factors that will lead to chronic kidney disease. Despite all the potential therapeutic targets highlighted by the pathophysiological knowledge, further works remain necessary to find a way to prevent these injuries.

Protein Kinase C-δ Mediates Kidney Tubular Injury in Cold Storage-Associated Kidney Transplantation.

BACKGROUND: Kidney injury associated with cold storage is a determinant of delayed graft function and the long-term outcome of transplanted kidneys, but the underlying mechanism remains elusive. We previously reported a role of protein kinase C-δ (PKCδ) in renal tubular injury during cisplatin nephrotoxicity and albumin-associated kidney injury, but whether PKCδ is involved in ischemic or transplantation-associated kidney injury is unknown. METHODS: To investigate PKCδ's potential role in injury during cold storage-associated transplantation, we incubated rat kidney proximal tubule cells in University of Wisconsin (UW) solution at 4°C for cold storage, returning them to normal culture medium at 37°C for rewarming. We also stored kidneys from donor mice in cold UW solution for various durations, followed by transplantation into syngeneic recipient mice. RESULTS: We observed PKCδ activation in both in vitro and in vivo models of cold-storage rewarming or transplantation. In the mouse model, PKCδ was activated and accumulated in mitochondria, where it mediated phosphorylation of a mitochondrial fission protein, dynamin-related protein 1 (Drp1), at serine 616. Drp1 activation resulted in mitochondrial fission or fragmentation, accompanied by mitochondrial damage and tubular cell death. Deficiency of PKCδ in donor kidney ameliorated Drp1 phosphorylation, mitochondrial damage, tubular cell death, and kidney injury during cold storage-associated transplantation. PKCδ deficiency also improved the repair and function of the renal graft as a life-supporting kidney. An inhibitor of PKCδ, δV1-1, protected kidneys against cold storage-associated transplantation injury. CONCLUSIONS: These results indicate that PKCδ is a key mediator of mitochondrial damage and renal tubular injury in cold storage-associated transplantation and may be an effective therapeutic target for improving renal transplant outcomes.

Identification of Factors Associated With Acute Tubular Necrosis Following Kidney Transplant in Northern Mexico: Increased Risk With Cold Ischemia After 8 Hours.

AIM: To identify potential risk factors associated with the incidence of acute tubular necrosis (ATN) following kidney transplant in a sample of patients from northern Mexico. METHODS: Secondary analysis of data extracted from clinical files of patients who underwent a kidney transplant between 2000 and 2017 at Christus Muguerza Hospital in the city of Chihuahua. The final sample with complete data included 485 patients. ATN was diagnosed in 13.2% of patients using pathologic, clinical, and laboratory criteria. Adjusted odds ratio (ORs) with 95% CIs from multivariate binary logistic regression were used to identify predictors of ATN. RESULTS: Only 4 of 21 variables analyzed remained statistically significant in the final adjusted model. Cold and warm ischemia followed time-trend patterns with higher odds with longer ischemia times. For cold ischemia, compared with 0 to 240 minutes, ORs were 1.32 (95% CI, 0.49-3.51) for 241-480 minutes, 4.87 (95% CI, 2.29-10.3) for 481-960 minutes, and 10.0 (95% CI, 2.86-35.0) for > 960 minutes; for warm ischemia, compared with 40 to 59 minutes, these were 6.27 (95% CI, 1.95-20.8) for 60-70 minutes and 10.32 (95% CI, 1.95-54.4) for 71-110 minutes. Hypotension during surgery was associated with a higher chance of ATN (OR, 15.9; 95% CI, 4.97-50.9). When the recipients' age was 30 years or older, the probability also increased significantly (OR, 2.88; 95% CI, 1.09-7.57). The final model fitted well and explained 27% of the probability to develop ATN after a kidney transplant. CONCLUSION: Shortening the duration of ischemia and avoiding hypotension during surgery is essential to prevent ATN following a kidney transplant.

Orthostatic Renal Transplant Compression Following Weight Gain Leading to Acute Kidney Injury.

BACKGROUND: We present a first case of orthostatic renal graft compression and acute kidney injury following weight gain. CASE REPORT: A 61-year-old male with a second cadaveric transplant presented with acute kidney injury - creatinine rise from 80 to 210 µmol/L (0.90 to 2.38 mg/dL). His medical history included diabetes, hypertension, ischemic heart disease, and obesity despite bariatric surgery. Renal biopsy was consistent with acute tubular necrosis. Serial renovascular duplex studies showed absence of diastolic flow and reduced renal perfusion despite a patent renal transplant artery and vein. Raising the fatty apron cephalad normalized renal blood flow with resistive indices throughout the kidney. Subsequent laparascopy ruled out adhesional obstruction and carbon dioxide angiogram confirmed normal transplant vessels, anastomotic sites, and intrarenal branches. He was treated with bedrest and an abdominal support belt with improvement of creatinine to 100 to 110 µmol/L (1.1-1.2 mg/dL). CONCLUSIONS: Transplant physicians and surgeons need to be aware of positional renal graft compression from an enlarged bulky omentum and fatty apron. Diagnosis requires positional sonography.

Maternal undernutrition aggravates renal tubular necrosis and interstitial fibrosis after unilateral ureteral obstruction in male rat offspring.

Maternal undernutrition is known to reduce glomerular number but it may also affect tubulointerstitium, capillary density, and response to oxidative stress. To investigate whether the latter elements are affected, we examined the response to unilateral ureteral obstruction (UUO), an established model of renal tubulointerstitial fibrosis, in the kidney of offspring from control and nutrient restricted rats. Six-week old male offspring from rats given food ad libitum (CON) and those subjected to 50% food restriction throughout pregnancy (NR) were subjected to UUO for 7 days. Body weight was significantly lower in NR. Systolic blood pressure and blood urea nitrogen increased similarly in CON and NR after UUO. Tubular necrosis in the obstructed kidney, on the other hand, was more extensive in NR. Also, the collagen area, a marker of fibrosis, of the obstructed kidney was significantly increased compared with the contralateral kidney only in NR. Capillary density was decreased similarly in the obstructed kidney of CON and NR compared with the contralateral kidney. Urine nitrate/nitrite, a marker of nitric oxide production, from the obstructed kidney was significantly increased in NR compared with CON. Nitrotyrosine, a marker of nitric oxide-mediated free radical injury, was increased in the obstructed kidney compared with the contralateral kidney in both CON and NR, but the extent was significantly greater in NR. In conclusion, more severe tubular necrosis and fibrosis after UUO was observed in NR, which was thought to be due to increased nitrosative stress.

Assessment and prediction of acute kidney injury in patients with decompensated cirrhosis with serum cystatin C and urine N-acetyl-ß-D-glucosaminidase.

BACKGROUND AND AIM: For appropriate management of acute kidney injury (AKI) in cirrhotic patients, accurate differentiation of the types of AKI, prerenal azotemia (PRA), hepatorenal syndrome (HRS), and acute tubular necrosis (ATN) is very important. Urine N-acetyl-ß-D-glucosaminidase (NAG) has been proposed as a good tubular injury marker in many studies, but its efficacy in cirrhosis is unclear. This study was performed to evaluate the usefulness of urine NAG in patients with decompensated cirrhosis. METHODS: In 114 hospitalized patients with decompensated cirrhosis, we assessed serum creatinine, cystatin C, and urine NAG levels as markers for AKI differentiation and development and patient mortality. RESULTS: Thirty patients diagnosed with AKI at baseline had significantly higher serum creatinine and cystatin C levels, urine NAG levels, and Child-Pugh scores than those without AKI. Only urine NAG levels were significantly higher in patients with ATN than those with PRA or HRS (116.1 ± 46.8 U/g vs 39.4 ± 20.2 or 54.0 ± 19.2 U/g urinary creatinine, all P < 0.05). During a median follow up of 6.1 months, AKI developed in 17 of 84 patients: PRA in nine, HRS in six, and ATN in three. Higher serum cystatin C and urine NAG levels were independent predictors of AKI development in patients with decompensated cirrhosis. Survival was significantly associated with low serum cystatin C and urine NAG levels. CONCLUSION: Serum cystatin C and urine NAG levels are useful to differentiate types of AKI and are strong predictors for AKI development and mortality in patients with decompensated cirrhosis.

A Rare Presentation of Immunoglobulin A Nephropathy: Acute Kidney Injury.

BACKGROUND: Acute kidney injury (AKI) is known as an uncommon presentation in immunoglobulin A nephropathy (IgAN). The aim of our study was to analyze the clinical data and biopsy findings in IgAN patients presenting with AKI. METHODS: We performed a retrospective analysis of all subjects who had biopsy-proven IgAN and presented with AKI during June 2002 September 2015. The following data were obtained from medical records. RESULTS: A total of 15 patients of 123 patients (12.2%) with primary IgAN admitted with AKI. Patients were generally male (73.3%), with a median age of 38 (interquartile range; IQR, 2,944) years. The serum creatinine at admission was above the normal range (median 2.3 [IQR, 2.14.7] mg/dL]). On histology, cellular/fibrocellular crescents were present in 6 patients. In most cases (53.3%), pathologic abnormalities associated with acute tubular injury/necrosis were defined. Red blood cell casts in tubules were present in 6 cases (40%). In all cases, interstitial mixed inflammatory cell infiltration was observed. In 4 cases, admixed eosinophils were also found. In 3 patients, biopsy specimens showed acute thrombotic microangiopathy lesions (20%). Median follow-up time was 13 (IQR, 346) months. Six patients (40%) progressed to end-stage renal disease (ESRD). Among patients diagnosed with primary IgAN and presenting without AKI, only 4 patients progressed to ESRD. The proportion of patients who progressed to ESRD presenting with AKI was significantly higher than the patients presenting without AKI (p = 0.000). CONCLUSIONS: In conclusion, AKI complicates IgAN more often.

Lack of Impact of Hyperchloremia in Brain-Dead Organ Donors on the Onset of Kidney Allograft Function in the Recipients.

BACKGROUND: Hyperchloremia produces renal vasoconstriction and fall in glomerular filtration rate. In 90% of brain-dead organ donors, diabetes insipidus develops, characterized by inappropriate diuresis, hyperosmolality, and hyperchloremia. The aim of this study was to determine the relationship between the serum concentration of chlorides of the donor and the onset of the function of the kidney allograft in the recipient. METHODS: We retrospectively studied 213 donors and kidney allograft recipients. Serum creatinine concentrations and glomerular filtration rates on the 1st, 7th, and 30th days after transplantation of the recipients from hyperchloremic donors were compared with the recipients from normochloremic donors, as well as the incidences of acute tubular necrosis and delayed graft function. RESULTS: On the 1st day, serum creatinine concentrations of the recipients from hyperchloremic and normochloremic donors, respectively, were 448.2 ± 212.1 µmol/L and 502.2 ± 197.8 µmol/L (P = .1), on the 7th day, 168.6 ± 102.6 µmol/L and 196.9 ± 120.6 µmol/L (P = .13), and on the 30th day, 129.4 ± 43.3 µmol/L and 131.8 ± 43.6 µmol/L (P = .73). The differences were statistically significant. The groups also did not differ significantly in glomerular filtration rates and incidences of acute tubular necrosis and delayed graft function. CONCLUSIONS: In this study, no significant correlation between serum chloride concentrations of the organ donors and the onset of the function of kidney allografts in the recipients was found.

A Case of Oxalate Nephropathy: When a Single Cause Is Not Crystal Clear.

Hyperoxaluria can result in oxalate nephropathy with intratubular calcium oxalate crystallization and acute tubular injury. Primary inherited enzymatic deficiency or secondary causes such as excessive dietary intake, enteric increased absorption, or high doses of vitamin C, which is metabolized to oxalate, may underlie hyperoxaluria and oxalate nephropathy. We report a case of acute kidney injury due to oxalate nephropathy in a patient using chelating therapy with oral ethylenediamine tetra acetic acid (EDTA), intravenous supplementation with vitamin C, and chronic diarrhea and discuss the potential kidney damage these factors can cause in particular settings. To our knowledge, this is the first report suggesting an association between oral EDTA and oxalate nephropathy.

Tubular Peroxiredoxin 3 as a Predictor of Renal Recovery from Acute Tubular Necrosis in Patients with Chronic Kidney Disease.

Peroxiredoxin 3 (PRX3) is a mitochondrial antioxidant that regulates apoptosis in various cancers. However, whether tubular PRX3 predicts recovery of renal function following acute kidney injury (AKI) remains unknown. This retrospective cohort study included 54 hospitalized patients who had AKI with biopsy-proven acute tubular necrosis (ATN). The study endpoint was renal function recovery within 6 months. Of the 54 enrolled patients, 25 (46.3%) had pre-existing chronic kidney disease (CKD) and 33 (61%) recovered renal function. Tubular PRX3 expression was higher in patients with ATN than in those without renal function recovery. The level of tubular but not glomerular PRX3 expression predicted renal function recovery from AKI (AUROC = 0.76). In multivariate Cox regression analysis, high PRX3 expression was independently associated with a higher probability of renal function recovery (adjusted hazard ratio = 8.99; 95% CI 1.13-71.52, P = 0.04). Furthermore, the discriminative ability of the clinical model for AKI recovery was improved by adding tubular PRX3. High tubular PRX3 expression was associated with a higher probability of renal function recovery from ATN. Therefore, tubular PRX3 in combination with conventional predictors can further improve recovery prediction and may help with risk stratification in AKI patients with pre-existing CKD.

Acute tubular necrosis following transurethral resection of the Prostate using Glycine as irrigating fluid.

Transurethral resection of the prostate is currently the gold standard for the surgical treatment of the benign prostatic hyperplasia. This surgery may lead transurethral resection of the prostate (TURP) syndrome and in some cases, acute tubular necrosis can develop. We report a patient who developed hyponatremia, hemolysis and oliguric acute renal failure as a major complication following TURP using glycine as irrigating fluid.A 64-year-old man was admitted for a prostate resection procedure. Physical examination revealed a healthy elderly man. Preoperative laboratory data showed serum sodium 140 mEq/L, blood urea nitrogen (BUN) 0.6 g/L, creatinine 0.7 mg/dL and hemoglobin 12.9 g/dL. Few hours after, the patient becomes incoherent and developed oliguria, nausea and vomiting. The laboratory data revealed rapidly elevating BUN and creatinine levels (BUN 2.4 g/L; creatinine 6.1 mg/dL), the serum sodium concentration decreased by 14 meq/L. A decreased hemoglobin level (7.4 g/dL) with an elevated lactate dehydrogenase level (665 U/L) was observed. Renal ultrasonography was normal. The diagnosis of acute tubular necrosis complicating TURP syndrome was retained. The hyponatremia was slowly corrected to 132 mmol/L by diuresis and fluid restriction. The renal function recovered after four hemodialysis sessions. Using glycine as an irrigant for TURP may cause hyponatremia, hemolysis and also acute renal failure, especially in patients with longer resection time. It is necessary to carry out every effort to shorten resection time and avoid extravasation during surgery.

Role of Oxidative Stress in Drug-Induced Kidney Injury.

The kidney plays a primary role in maintaining homeostasis and detoxification of numerous hydrophilic xenobiotics as well as endogenous compounds. Because the kidney is exposed to a larger proportion and higher concentration of drugs and toxins than other organs through the secretion of ionic drugs by tubular organic ion transporters across the luminal membranes of renal tubular epithelial cells, and through the reabsorption of filtered toxins into the lumen of the tubule, these cells are at greater risk for injury. In fact, drug-induced kidney injury is a serious problem in clinical practice and accounts for roughly 20% of cases of acute kidney injury (AKI) among hospitalized patients. Therefore, its early detection is becoming more important. Usually, drug-induced AKI consists of two patterns of renal injury: acute tubular necrosis (ATN) and acute interstitial nephritis (AIN). Whereas AIN develops from medications that incite an allergic reaction, ATN develops from direct toxicity on tubular epithelial cells. Among several cellular mechanisms underlying ATN, oxidative stress plays an important role in progression to ATN by activation of inflammatory response via proinflammatory cytokine release and inflammatory cell accumulation in tissues. This review provides an overview of drugs associated with AKI, the role of oxidative stress in drug-induced AKI, and a biomarker for drug-induced AKI focusing on oxidative stress.

Recurrence of Hyperoxaluria and Kidney Disease after Combined Intestine-Kidney Transplantation for Enteric Hyperoxaluria.

BACKGROUND: Enteric hyperoxaluria (EH) occurs with a rate of 5-24% in patients with inflammatory bowel disease, ileal resection and modern bariatric surgery. The excessive absorption of calcium oxalate causes chronic kidney disease (CKD) in patients with EH. In the literature, a single experience was reported in combined intestine-kidney transplantation (CIKTx) in patients with CKD due to EH. METHODS: After a report of 2 successful cases of CIKTx in patients with EH and CKD, one was performed at our center in a 59-year-old Caucasian female who developed intestinal failure with total parenteral nutrition (TPN) dependence after a complication post-bariatric surgery. Before CIKTx, she underwent kidney transplantation alone (KTA) twice, which failed due to oxalate nephropathy. RESULTS: In July 2014, the patient underwent CIKTx and bilateral allograft nephrectomy to avoid EH and oxalate stone burden. The postoperative course was complicated with acute tubular necrosis due to the use of high pressors related to perioperative bleeding. The patient was discharged 79 days after CIKTx with a serum creatinine (sCr) of 1.2 mg/dl and free of TPN. Her sCr increased at 7 months and a renal biopsy showed oxalate nephropathy. SLC26A6 (oxalate transporter) staining was significantly diminished in native duodenum/rectum as well as in intestinal allograft compared to control. CONCLUSIONS: KTA in patients with CKD secondary to EH should not be recommended due to high risk of recurrence. Although other centers showed good long-term outcomes in CIKTx, our patient experienced recurrence of EH due to oxalate transporter defect, early kidney allograft dysfunction and prolonged antibiotic use.