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Renal failure is common in patients with glomerular disease. Although renal failure may result from the glomerular lesion itself, it is also observed in patients with minimal glomerular alterations. Degenerative changes and necrosis of the tubular epithelium are common findings in kidney biopsies from these patients. The aim of this work is to examine the association between acute tubular necrosis (ATN) and renal failure in patients with glomerulopathy and to estimate the relationship between the degree of ATN and renal failure in these patients. Data on age, sex, presence of nephrotic syndrome, and renal failure were recorded for 149 patients, who underwent a renal biopsy for the diagnosis of glomerulopathy. The biopsies were reviewed, and ATN, when present, was classified as one of four grades depending on its intensity. The mean age of the patients was 21 ± 16 years. Eighty patients (54%) were male, 43 (42%) had renal failure, 104 (72%) had nephrotic syndrome, and 66 (45%) had minimal change disease or focal segmental glomerulosclerosis. ATN was present in 115 (77%) patients. The frequency of renal failure was directly correlated with the intensity of ATN [odds ratio (OR) of 26.0 for patients with grade 2 lesions and OR of 45.5 for patients with grade 3 lesions]. ATN is a common finding in the biopsies of patients with glomerulopathy. The severity of ATN is directly associated with the frequency of renal failure in these patients.

Forty patients with terminal cirrhosis and 40 patients with fulminant hepatic failure-all consecutively admitted-were studied with regard to incidence, types, and prognosis of complicating renal insufficiency. Renal failure was considered present when the serum creatinine was greater than 0.20 mmol/l. Of the patients with cirrhosis 26 (65%) developed renal failure. In 15 the type was functional, in three due to acute tubular necrosis, and in eight indeterminable. Of the patients with fulminant hepatic failure 22 (55%) had renal insufficiency; of these 13 had functional renal failure, five acute tubular necrosis, and in four the type was indeterminable. In both categories of patients, renal failure was equally frequent among patients with or without gastrointestinal bleeding and with or without ascites or diuretic therapy. The biochemical tests of liver function were similar in patients with or without renal failure in both categories. The mean renal blood flow in seven unselected patients with fulminant hepatic failure was reduced in the same order as previously observed in patients with cirrhosis. In terminal cirrhosis the mortality rate was 88% in the presence of renal failure, 71% in its absence (p greater than 0.05), while the same figures in fulminant hepatic failure were 100% and 67% (p less than 0.05). The incidence, relative frequency, and prognosis of renal failure were not different in the two conditions, indicating identical pathophysiological circumstances.

Renal function was evaluated in 40 patients with fulminant hepatic failure, They were divided into two groups on the basis of glomerular filtration rates greater than 40 ml/min or less than 25 ml/min. A number of patients in group 1 had markedly abnormal renal retention of sodium together with a reduced free water clearance and low potassium excretion which could be explained by increased proximal tubular reabsorption of sodium. The patients in group 2 had evidence that renal tubular integrity was maintained when the glomerular filtration rate was greater than or equal ml/min (functional renal failure), but evidence of tubular damage was present when this was less than 3 ml/min (acute tubular necrosis).

Twelve patients with otherwise uncomplicated acute viral hepatitis (two were HBsAg-positive) developed renal failure. Apart from dehydration due to repeated vomiting in one patient, no factor responsible for precipitating renal failure could be identified. The clinical course was characterised by renal failure with plasma urea concentrations reaching maximum values of 26-69 mmol/l (175-416 mg/100 ml). Ten patients needed dialysis for up to two weeks. Seven patients recovered completely, while the other five died from sepsis. The types of renal failure were similar to those described in fulminant hepatic failure and cirrhosis--namely, functional renal failure in five patients and acute tubular necrosis in seven. Two of the patients with functional renal failure later developed tubular necrosis. The mechanism responsible for renal failure in acute viral hepatitis is uncertain, though endotoxaemia may contribute.

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A review is presented of ten years' experience with the differential diagnosis of oliguria, utilizing the standard tests of renal function with the addition of the phenolsulfonphthalein excretion and urinary chloride measurements. The histories of 60 patients seen in consultation because of 24-hour urinary volume of less than 400 ml were studied in order to clarify the value of these tests. Particular attention was given to the postoperative “dilution state,” the oliguria of which tends to mimic that of “acute tubular necrosis.”

In only 25 per cent of the 60 cases was “acute tubular necrosis” responsible for the oliguria. In the remaining 75 per cent of patients, oliguria was due either to the effects of simple dehydration without tubular damage, or to tubular dysfunction on a physiologic rather than an organic basis. Thus, three out of four patients with oliguria required aggressive and specific fluid-electrolyte therapy, often with the intensive use of potassium. One out of four required the opposite in therapy—controlled dehydration without added potassium and, on occasion, peritoneal or extracorporeal dialysis, in order to allow six to ten days for tubular repair.

Introduction

Acute kidney injury in the setting of adult minimal change disease is associated with proteinuria, hypertension and hyperlipidemia but anemia is usually absent. Renal biopsies exhibit foot process effacement as well as tubular interstitial inflammation, acute tubular necrosis or intratubular obstruction. We recently managed a patient with unique clinical and pathological features of minimal change disease, who presented with severe anemia and acute kidney injury, an association not previously reported in the literature.

Case presentation

A 60-year-old Indian-American woman with a history of hypertension and diabetes mellitus for 10 years presented with progressive oliguria over 2 days. Laboratory data revealed severe hyperkalemia, azotemia, heavy proteinuria and progressively worsening anemia. Urine eosinophils were not seen. Emergent hemodialysis, erythropoietin and blood transfusion were initiated. Serologic tests for hepatitis B, hepatitis C, anti-nuclear antibodies, anti-glomerular basement membrane antibodies and anti-neutrophil cytoplasmic antibodies were negative. Complement levels (C3, C4 and CH50) were normal. Renal biopsy unexpectedly displayed 100% foot process effacement. A 24-hour urine collection detected 6.38 g of protein. Proteinuria and anemia resolved during six weeks of steroid therapy. Renal function recovered completely. No signs of relapse were observed at 8-month follow-up.

Conclusion

Adult minimal change disease should be considered when a patient presents with proteinuria and severe acute kidney injury even when accompanied by severe anemia. This report adds to a growing body of literature suggesting that in addition to steroid therapy, prompt initiation of erythropoietin therapy may facilitate full recovery of renal function in acute kidney injury.

Renal micropuncture studies have greatly changed our views on the pathophysiology of acute renal failure caused by nephrotoxins. Formerly, this type of renal insufficiency was attributed to a direct effect of the nephrotoxins on tubule epithelial permeability. According to that theory, glomerular filtration was not greatly diminished, the filtrate formed being absorbed almost quantitatively and nonselectively across damaged tubule epithelium. Studies in a wide variety of rat models have now shown glomerular filtration to be reduced to a level which will inevitably cause renal failure in and of itself. Passive backflow of filtrate across tubular epithelium is either of minor degree or nonexistent even in models where frank tubular necrosis has occurred. This failure of filtration cannot be attributed to tubular obstruction since proximal tubule pressure is distinctly subnormal in most models studied. Instead, filtration failure appears best attributed to intrarenal hemodynamic alterations. While certain facts tend to incriminate the renin-angiotensin system as the cause of the hemodynamic aberrations, others argue to the contrary. The issue is underactive investigation.

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Acute kidney injury (AKI) is a recognised complication of intravenous pentamidine therapy. A direct nephrotoxic effect leading to acute tubular necrosis has been postulated. We report a case of severe renal allograft dysfunction due to nebulised pentamidine. The patient presented with repeated episodes of AKI without obvious cause and acute tubular necrosis only on renal histology. Nebulised pentamidine was used monthly as prophylaxis for Pneumocystis jirovecii pneumonia, and administration preceded the creatinine rise on each occasion. Graft function stabilised following discontinuation of the drug. This is the first report of nebulized pentamidine-induced reversible nephrotoxicity in a kidney allograft. This diagnosis should be considered in a case of unexplained acute renal allograft dysfunction.

We report a case of nephrotic syndrome and acute renal failure apparently induced by sunitinib. A 67-year-old man with a history of metastatic renal cell carcinoma presented with progressive kidney dysfunction with proteinuria, general edema, and body weight gain of 21 kg after undergoing 3 weeks of sunitinib therapy. The patient had taken no other over-the-counter medications, and all other possible causes of nephrotic syndrome were excluded. The Naranjo Adverse Drug Reaction Probability Scale score for this event was 6, indicating a high probability that the observed presentations were associated with use of the drug. However, despite the discontinuation of sunitinib, his condition deteriorated, and hemodialysis was initiated for respiratory distress. A renal biopsy was performed, which revealed ischemic acute tubular necrosis with minimal change nephropathy. In conclusion, nephrologists and oncologists should be aware that nephrotic syndrome with ischemic acute tubular necrosis is a possible adverse effect of sunitinib. For early diagnosis of this condition and to avoid renal damage, we recommend differential diagnosis of serum creatinine and proteinuria in patients undergoing sunitinib therapy.

The authors report a case of a 43-year-old woman who presented with second degree chemical burns to 9% of the total body surface area due to cutaneous contact with cresol. This was associated with acute oliguric kidney injury requiring haemodialysis. In contrast to previous reports of cresol ingestion, the patient did not have evidence of hepatic dysfunction, possibly due to a low cresol concentration in the portal vein and liver. Renal histopathology showed regional accentuated tubular necrosis and disruption of the tubular basement membrane. Renal toxicity was thought to be due to direct tubular toxicity and impaired renal blood flow.

Hepatic ischemia reperfusion (IR) is the leading cause of acute liver failure (ALF) during the perioperative period and patients with ALF frequently develop acute kidney injury (AKI). There is no effective therapy for AKI associated with ALF because pathomechanisms are incompletely characterized, in part due to the lack of an animal model. In this study, we characterize a novel murine model of AKI following hepatic IR. Mice subjected to ~70% liver IR not only developed acute liver dysfunction, but also developed severe AKI 24 hr after liver injury. Mice subjected to liver IR developed histological changes of acute tubular injury including focal proximal tubular cell necrosis involving the S3 segment, cortical tubular ectasia, focal tubular simplification and granular bile/heme cast formation. In addition, there was focal interstitial edema and hyperplasia of the juxtaglomerular apparatus. Inflammatory changes in the kidney after hepatic IR included neutrophil infiltration of the interstitium and upregulation of several pro-inflammatory mRNAs (tumor necrosis factor-α, keratinocyte derived cytokine, monocyte chemotactic protein-1, macrophage inflammatory protein-2, intercellular adhesion molecule-1). In addition, marked renal endothelial cell apoptosis was detected involving peritubular interstitial capillaries, accompanied by increased renal vascular permeability. Finally, there was severe disruption of renal proximal tubule epithelial filamentous-actin. Our results show that AKI rapidly and reproducibly develops in mice after hepatic IR and is characterized by renal tubular necrosis, inflammatory changes and interstitial capillary endothelial apoptosis. Our murine model of AKI after liver injury closely mimics human AKI associated with ALF and may be useful in delineating the mechanisms and potential therapies for this common clinical condition.

Objective: To investigate the correlation between circulating endothelial cells (CECs) and vascular lesions in renal allografts.

Methodology: Sixty-two renal transplant patients were divided into four groups according to biopsy data. CECs were isolated from peripheral blood with anti-CD136-coated immunomagnetic Dynabeads and counted by microscopy during biopsy. CEC numbers were compared in each group, as well as the correlation between CECs and C4d and vascular changes in different groups.

Result: CECs counts were higher in the acute rejection (AR) with endarteritis group than in the normal group (p < 0.01), acute tubular necrosis (ATN) group (p < 0.01) and chronic allograft nephropathy (CAN) group (p < 0.01), there were no difference among ATN, normal and CAN) group (p = 0.587). There was no difference among the normal group without hyaline, normal group with hyaline and CAN with hyaline group. An increasing CECs count was related to C4d-positive AR (p = 0.008; κ score = 0.519) and infiltration of inflammatory cells (p = 0.002, κ score = 0.573) in proximal tubule cells (PTCs). The CECs count decreased after intensive therapy in five patients (p = 0.001).

Conclusion: Elevation of the CEC count in blood was related to endarteritis. Elevation of CEC count was related to C4d deposition and infiltration of inflammatory cells in PTCs.

The paradigm for recovery of the renal tubule from acute tubular necrosis is that surviving cells from the areas bordering the injury must migrate into the regions of tubular denudation and proliferate to re-establish the normal tubular epithelium. However, therapies aimed at stimulating these events have failed to alter the course of acute renal failure in human trials. In the present study, we demonstrate that Lin–Sca-1+ cells from the adult mouse bone marrow are mobilized into the circulation by transient renal ischemia and home specifically to injured regions of the renal tubule. There they differentiate into renal tubular epithelial cells and appear to constitute the majority of the cells present in the previously necrotic tubules. Loss of stem cells following bone marrow ablation results in a greater rise in blood urea nitrogen after renal ischemia, while stem cell infusion after bone marrow ablation reverses this effect. Thus, therapies aimed at enhancing the mobilization, propagation, and/or delivery of bone marrow stem cells to the kidney hold potential as entirely new approaches for the treatment of acute tubular necrosis.

Human immunodeficiency virus (HIV) is associated with several renal syndromes including acute and chronic renal failures, but the underlying pathogenic mechanisms are unclear. HIV and feline immunodeficiency virus (FIV) share numerous biological and pathological features, including renal alterations. We investigated and compared the morphological changes of renal tissue of 51 experimentally and 21 naturally infected cats. Compared to the latter, the experimentally infected cats exhibited some mesangial widening and glomerulonephritis, milder proteinuria, and lower tubular and interstitial alterations. The numbers of giant protein tubular casts and tubular microcysts were also lower. In contrast, diffuse interstitial infiltrates and glomerular and interstitial amyloidosis were detected only in naturally infected cats. Similar alterations are found in HIV infected patients, thus supporting the idea of a causative role of FIV infection in renal disease, and underlining the relevance of the FIV and its natural host as an animal model for investigating lentivirus-associated nephropathy.

Background

Hornet stings are generally associated with local and occasionally anaphylactic reactions. Rarely systemic complications like acute renal failure can occur following multiple stings. Renal failure is usually due to development of acute tubular necrosis as a result of intravascular haemolysis, rhabdomyolysis or shock. Rarely it can be following development of acute tubulo-interstitial nephritis.

Case presentation

We describe a young male, who was stung on face, head, shoulders and upper limbs by multiple hornets (Vespa orientalis). He developed acute renal failure as a result of acute tubulo-interstitial nephritis and responded to steroids.

Conclusion

Rare causes of acute renal failure like tubulo-interstitial nephritis should be considered in a patient with persistent oliguria and azotemia following multiple hornet stings. Renal biopsy should be undertaken early, as institution of steroid therapy may help in recovery of renal function

Measurements of urinary lysozyme were used to evaluate renal tubular integrity in 34 patients with cirrhosis or fulminant hepatic failure who had developed renal impairment. In 18 of the patients the lysozyme values were normal but in the remaining 16 were increased, supporting previous concepts that renal failure complicating hepatocellular disease may occur both without and with tubular necrosis. The lysozyme values were inversely related to the creatinine clearance, suggesting that the development of tubular necrosis may be determined by the level of renal perfusion. The validity of simpler laboratory tests often used to assess renal tubular integrity--namely, the urine sodium concentration, the urine:plasma osmolality ratio, and casts in the urine sediment--was evaluated by comparison with the lysozyme measurements. The urine sodium concentration was of most value and the findings in the sediment were of no value at all.

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High-dose excretion urography has been carried out in 32 patients presenting with non-obstructive acute oliguric or non-oliguric renal failure. An early, dense, persisting nephrogram has been observed in all patients with acute uncomplicated tubular necrosis and in patients with acute oliguric pyelonephritis. This appearance is modified by the presence of pre-existing renal disease. Different patterns have been observed in patients with acute glomerular disease, severe renal ischaemia, and chronic glomerular disease. The study demonstrates that careful analysis of the evolution of the nephrogram in patients with acute renal failure provides valuable information as to the nature of the parenchymal disease.

Acute renal failure is an unusual complication of wasp stings. We report two cases of renal failure after multiple wasp stings (Vespa affinis). Both patients had evidence of intravascular haemolysis, hepatic dysfunction, oligo-anuria and azotaemia and required dialysis. The first patient had severe hemolysis, rhabdomyolysis, pigment and venom nephropathy and died on the 8th day in hospital. The second patient, who recovered completely in 3 weeks time with steroid and antihistaminic therapy, had interstitial nephritis. Although acute renal failure after wasp stings is typically caused by acute tubular necrosis (ATN) in the setting of haemolysis or rhabdomyolysis, in some patients, acute renal failure may result from a direct nephrotoxic effect or acute interstitial nephritis from a hypersensitivity reaction.

Highly active antiretroviral therapy (HAART) and other medical therapies for HIV-related infections have been associated with toxicities. Antiretroviral therapy can contribute to renal dysfunction directly by inducing acute tubular necrosis, acute interstitial nephritis, crystal nephropathy, and renal tubular disorders or indirectly via drug interactions. With the increase in HAART use, clinicians must screen patients for the development of kidney disease especially if the regimen employed increases risk of kidney injury. It is also important that patients with chronic kidney disease (CKD) are not denied the best combinations, especially since most drugs can be adjusted based on the estimated GFR. Early detection of risk factors, systematic screening for chronic causes of CKD, and appropriate referrals for kidney disease management should be advocated for improved patient care. The interaction between immunosuppressive therapy and HAART in patients with kidney transplants and the recent endorsement of tenofovir/emtricitabine by the Centers for Disease Control (CDC) for preexposure prophylaxis bring a new dimension for nephrotoxicity vigilance. This paper summarizes the common antiretroviral drugs associated with nephrotoxicity with particular emphasis on tenofovir and protease inhibitors, their risk factors, and management as well as prevention strategies.

We report a patient with unknown primary undifferentiated carcinoma who developed acute renal failure associated with interstitial fibrosis following pemetrexed therapy. Despite drug withdrawal, renal function remained altered and the patient experienced chronic renal insufficiency. Pemetrexed disodium (Alimta™) is a multitargeted antifolate agent approved by the Food and Drug Administration (FDA) for patients diagnosed with mesothelioma and non-small cell lung cancer. This drug is almost exclusively cleared by renal excretion [1]. The most common side effects are hematologic dose-limiting toxicities and nonhematologic toxicities including fatigue, diarrhea, nausea, mucositis and rash. Although few cases of renal failure have been published, no study has reported on the renal pathological findings in this setting. We present a case of acute tubular necrosis associated with interstitial fibrosis after pemetrexed therapy.

Eleven out of a series of twenty-nine patients (37-9%) with acute copper sulphate poisoning developed acute renal failure. Intravascular haemolysis appeared to be the chief factor responsible for renal lesions in these patients. Histological lesions observed in the kidney varied from those of mild shock to well established acute tubular necrosis. In one case, granulomatous lesions were seen in response to tubulorrhexis. Renal failure was the chief indication for dialysis in ten patients, whereas one patient was dialysed primarily for removal of copper. Notwithstanding the adequate control of uraemia by dialysis, only six of the eleven patients recovered. Septicaemia was responsible for death in three, hepatic failure in one and methaemoglobinaemia in another. It is postulated that release of copper from haemolysed red cells during acute haemolytic episodes may initiate, or contribute to, the development of renal damage.

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Seven of 74 patients with early functioning cadaveric renal homografts developed acute oliguric renal failure after the second but before the ninth day post-transplantation. The syndrome characteristically begins with an abrupt and simultaneous decrease in creatinine clearance, urine volume and urine sodium concentration. After a variable period and despite a reduction in immunosuppressive therapy, a diuretic phase ensues and renal function is restored. Complications associated with the syndrome include groin hematoma, pulmonary edema and renal rupture with shock. Renal rupture does not require nephrectomy: if the hemorrhage is controlled, the transplanted organ will resume function. Angiographic studies show normal nephrograms, stretched arterial vasculature and filling defects in the veins. Percutaneous renal biopsy shows interstitial edema and hemorrhage, venous congestion and tubular necrosis. Evidence is presented to support the hypothesis that this is a form of rejection occurring as the result of injury to the renal venous system.

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Two infants are described who developed renal tubular and papillary necrosis. In one, severe problems of management occurred during the diuretic phase. In the other, the intravenous pyelogram showed characteristic changes during the acute illness. The urinary findings are compared with those in other dehydrated infants and a means of early diagnosis is suggested. In a dehydrated infant an initial urine sodium of more than 100 mEq/l., the persistence of osmolality below 500 mOsm/kg, and urea below 1500 mg/100 ml suggest renal tubular damage.

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Kidney injury molecule-1 (KIM-1) is a specific histological biomarker for diagnosing early tubular injury on renal biopsies. In this study, KIM-1 expression was quantitated in renal transplant biopsies by immunohistochemistry and correlated with renal function. None of the 25 protocol biopsies showed detectable tubular injury on histologic examination, yet 28% had focal positive KIM-1 expression. Proximal tubule KIM-1 expression was present in all biopsies from patients with histological changes showing acute tubular damage and deterioration of kidney function. In this group, higher KIM-1 staining predicted a better outcome with improved blood urea nitrogen (BUN), serum creatinine, and estimated glomerular filtration rate (eGFR) over an ensuing 18 months. KIM-1 was expressed focally in affected tubules in 92% of kidney biopsies from patients with acute cellular rejection. By contrast, there was little positive staining for Ki-67, a cell proliferation marker, in any of the groups. KIM-1 expression significantly correlated with serum creatinine and BUN, and inversely with the eGFR on the biopsy day. Our study shows that KIM-1 staining sensitively and specifically identified proximal tubular injury and correlated with the degree of renal dysfunction. KIM-1 expression is more sensitive than histology for detecting early tubular injury, and its level of expression in transplant biopsies may indicate the potential for recovery of kidney function.

Over a 3½ year period, 133 children with hepatic failure underwent orthotopic liver transplantation (OLT) at our center. Renal failure (creatinine clearance <20 ml/min/1.73 m2) was present in 19 (14.3%) of these children. In seven of the 19 children, renal failure was present before OLT, and in the other 12 after OLT. The causes of renal failure included hepatorenal syndrome in seven, postischemic acute tubular necrosis in five, severe prerenal azotemia in five, and cyclosporine nephrotoxicity in two. Eight other patients died of renal failure while awaiting emergency transplantation. Of the total of 31 deaths among 133 children who underwent OLT, nine occurred in the 19 patients with renal failure. Thus patients with OLT and renal failure had a significantly higher mortality than other patients with transplants (P <0.025). Dialysis was not associated with improved survival. The majority of deaths in patients with renal failure were related to severe hemorrhage, thromboembolic events, and systemic fungal infections. Our experience suggests that renal failure is common in children with hepatic failure and is associated with reduced patient survival after OLT.