Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0022672 (acute tubular necrosis)
 2,175 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Three urinary lysosomal enzymes, beta-glucuronidase (beta-Gluc), beta-galactosidase (beta-Gal) and N-acetyl-beta-D-glucosaminidase (NAG), were measured in twenty-one renal allograft recipients to evaluate their role in the diagnosis and prediction of rejection episodes, and in the prediction of eventual graft outcome. A fluorometric assay using methylumbelliferone substrates was used to measure the three enzymes in morning urine samples and enzyme activity was defined in terms of urine creatinine concentration. Urinary NAG levels increased significantly in 13/16 first rejection episodes and 4/4 instances of acute tubular necrosis and graft infarction. In 5 of the 16 first rejection episodes the NAG was predictive of the rejection. NAG was not useful in diagnosing second or subsequent rejections and beta-Gluc and beta-Gal were of little value in assessing any component of renal transplant pathology. As a prognostic index of eventual graft outcome, the peak urinary NAG was particularly encouraging. It correlated strongly with deterioration in graft function as time passed such that only 2/10 patients with peak NAG greater than 1400 Units had normal serum creatinines at 6 months post transplantation. Conversely 4/4 patients with peak NAG levels less than 700 Units had normal serum creatinine at that time. In our series the measurement of urinary NAG was a useful adjunct to the diagnosis of first rejections but appears to be more valuable in predicting graft outcome.
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PMID:Urinary lysosomal enzyme excretion after renal allotransplantation. 10 10

Proteinuria was studied in ten renal allograft recipients; it was defined as: (a) glomerular--characterized by predominant albumin excretion; (b) tubular--significant excretion of both albumin and low molecular weight (LMW) proteins; and (c) glomerulo-tubular or mixed type, a combination of the two. LMW protein and albumin were quantitated by polyacrylamide gel electrophoresis with sodium dodecyl sulfate. In the immediate posttransplant period, LMW protein and albumin excretion, expressed as a percentage of creatinine clearance, were high, revealing a mixed pattern, and excretion of both protein classes was higher than during both acute tubular necrosis and acute rejection crisis. Tubular proteinuria was observed in acute tubular necrosis; a glomerulo-tubular or mixed pattern of protein excretion in acute rejection crises.
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PMID:Proteinuria following renal transplantation. 32 83

Cadaver renal transplantation was performed in a 14-year-old girl with primary hyperoxaluria. Acute tubular necrosis was present initially, and a moderate rejection crisis occurred at 6 weeks. Renal biopsy performed at 4 months showed considerable deposition of calcium oxalate. Urinary excretion of oxalate varied between 315-371 mg/24 hr per 1.73 m2 (normal less than 50 mg). Despite these unfavourable factors, renal function has remained stable for the last 2 1/2 years; the serum creatinine is 1.5 mg/100 ml at 3 years. This is the longest surviving graft reported so far in documented primary hyperoxaluria. Graft failures in previous reports could in part be explained by additional complicating factors. It is concluded that renal transplantation is not necessarily contraindicated in primary hyperoxaluria.
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PMID:Prolonged survival after renal transplantation in primary hyperoxaluria of childhood. 34 53

An ivestigation was made of the effect of the duration of posttransplant renal failure on the late prognosis of graft as well as patient survival and on the frequency of complications in 102 patients who had a functioning graft at three months after transplantation. A direct correlation was found between duration of acute tubular necrosis (ATN) and the late prognosis of the graft. The creatinine clearance was significantly higher and the frequency of complications was lower in the group with immediate resumption of renal function. The mortality rate increased with the duration of ATN.
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PMID:Late prognosis in acute posttransplant renal failure in 102 patients. 37 68

This study compares the usefulness of serum and urine fibrin split products and the urinary enzyme, beta-glucuronidase, in the diagnosis and management of renal transplant rejection. Fibrin split products, determined by a tanned human red cell agglutination inhibition immunoassay, were measured as a reflection of the secondary fibrinolysis from fibrin deposited in the renal microvasculature as a result of rejection. Urinary beta-glucuronidase, expressed as the ratio of enzyme activity to creatinine concentration, was determined by a colorimetric technique following dialysis of urine to remove endogenous activators and inhibitors. Activity of this lysosomal enzyme is thought to reflect tubular injury. Twenty-nine renal transplant recipients (15 from living donors and 14 from cadaver donors) were evaluated. Both serum and urinary fibrin split products and urinary beta-glucuronidase were markedly elevated in the immediate postoperative period, probably reflecting ischemic trauma. Acute rejection occurring within the first three months was associated with elevations of fibrin split products (particularly urine) and beta-glucuronidase. Elevated values returned to normal following successful treatment with steroids and/or heparin, but remained high in the presence of continued rejection. After the first 48 hours post-transplant, in the absence of rejection, values for fibrin split products were within the normal range. Urinary beta-glucuronidase remained elevated if the transplanted kidney was recovering from acute tubular necrosis. Fibrin split products and urinary beta-glucuronidase were usually normal in chronic rejection.
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PMID:Comparison of serum and urine fibrin split products and urinary beta-glucuronidase in the diagnosis of renal transplant rejection. 37 26

Three hundred and fifty-eight renal imaging studies with quantitation of renal perfusion were performed following injection of 99Tcm-DTPA in 22 children aged 6--15 years with renal transplants. In 58 of 62 scans performed at the onset of a rejection episode, renal perfusion was decreased. This was the only feature of rejection in 6 episodes, in 5 of which the patient was oliguric due to post-operative acute tubular necrosis. In 4 episodes perfusion fell, but antirejection treatment was not given as a repeat scan was normal. On 18 occasions the plasma creatinine concentration (Pc) rose, but the scan was unchanged; no treatment was given and repeat Pc was normal. Three patients had a ureteric obstruction and 2 patients a lymphocoele detected from the images. There was no morbidity. Sequential renal scintigraphy was valuable in the early diagnosis of rejection and in the avoidance of unnecessary therapy.
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PMID:Serial quantitative imaging with 99Tcm-DTPA in pediatric renal transplantation. 38 5

After renal transplantation low urinary sodium concentration (UNa) has been used to diagnose acute rejection (AR), for the early phase of AR is often associated with reduced renal perfusion. Early postoperative graft failure without low UNa favors the diagnosis of ischemic tubular damage (ATN). As fractional excretion of filtered sodium (FENa) better reflects glomerulotubular balance in renal sodium handling, FENa was analyzed during the first 2 weeks in 118 renal allografts. From data on 41 transplants with good early renal function (GEF), a temporal profile of FENa was obtained and used to evaluate the behavior of FENa by means of standardized FENa (Z score). Individual subjects followed their own profile with a small deviation (delta Z less than 1.4 for 2 days). In 31 instances, acute rejection was diagnosed. In 14 with AR, the Z score deviated little; 2 responded to methylprednisolone given intravenously. In 17 with AR, the Z score fell significantly (delta Z greater than 1.5 for 2 days), an average of 2.6 days before the first rise in serum creatinine concentration; 15 responded to treatment. The difference between these two groups was significant (P less than 0.001). This functional heterogeneity and different responses to treatment may indicate different immunologic mechanisms which damage different target cells in the graft in AR. In 46 patients with acute tubular necrosis after cadaver kidney transplantation FENa was significantly higher than it was in the GEF group as early as the first posttransplantation day and approached normal as the renal function recovered. This behavior of FENa was clearly different from that in AR.
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PMID:Fractional excretion of sodium after renal transplantation. 39 Feb 18

The delayed onset of anuria/oliguria in acute tubular necrosis has been theorized to represent a complicating compartment syndrome, i.e., parenchymal swelling within an unyielding capsule. To test this proposition, 12 monkeys had suprarenal aortic cross-clamping, followed by unilateral renal decapsulation to create an experimental as well as a control kidney unit in the same animal. Histologic examination uniformly confirmed tubular necrosis at death or sacrifice. Subsequent split renal function studies (creatinine, urea, and free water clearances) indicated significantly greater maintenance of renal function by the decapsulated kidney than by its paired control. Clinical evaluation in 21 hemorrhagic shock patients, with the capsule of one kidney stripped, revealed on follow-up that 15 developed a renal failure consistent with acute tubular necrosis. Although three patients with polyuric failure died before split studies could be run and two others have been too recent for computer analysis to have been completed, nine of the remaining ten had significantly greater renal plasma flows (194 versus 121 ml/min M(2), p < .01) and significantly greater urine flows (.99 versus .18 ml/min M(2), p < .01) on the decapsulated side than on the control, as determined by differential renal scans. No significant difference in these same lateralized renal functions was noted in the tenth patient with renal failure and in the six survivors without renal failure. Renal decapsulation as prophylaxis reduced the anticipated incidence of oliguria/anuria from an expected 75% to 7% (p < .01) in these 21 shock patients. Such data suggest that delayed renal ischemia, possibly based on a compartment syndrome, may be the cause for a progression of acute tubular necrosis from polyuria to oliguria and then to anuria.
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PMID:Renal decapsulation in the prevention of post-ischemic oliguria. 40 54

The course of nonoliguric acute renal failure (ARF) in 11 patients was analyzed. The possible etiology of the renal failure was multiple in all cases and did not differ from that seen in oliguric acute tubular necrosis (ATN). Other than the urine volume, which ranged from 510 to 2,325 ml/day, there was no major clinical or biochemical difference between these cases of nonliguric ARF and those described for oliguric ATN. Creatinine clearance, however, was higher than anticipated in oliguric ATN and ranged from 2.8 to 15.0 ml/min. There was a direct relationship between creatinine clearance and daily urine volume. The essential difference between oliguric and nonoliguric renal failure appears to be the lesser degree of renal damage in the nonoliguric form.
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PMID:Nonoliguric acute renal failure. 42 44

A prospective analysis of the value of urinary diagnostic indices in ascertaining the cause of acute renal failure was undertaken. Our results show that in the setting of acute oliguria a diagnosis of potentially reversible prerenal azotemia is likely with urine osmolality greater than 500 mosm/kg H2O, urine sodium concentration less than 20 meq/litre, urine/plasma urea nitrogen ratio greater than 8, and urine/plasma creatinine ratio greater than 40. Conversely, a urine osmolality less than 350 mosm/kg, urine sodium concentration greater than 40 meq/liter, urine/plasma urea nitrogen ratio less than 3, and urine/plasma creatinine ratio less than 20 suggest acute tubular necrosis. A significant number of oliguric patients will not have urinary indices that fall within these guidelines. In this setting, urine sodium concentration divided by the urine-to-plasma creatinine ratio (the renal failure index) and the fractional excretion of filtered sodium provide a reliable means of differentiating reversible prerenal azotemia from acute tubular necrosis.
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PMID:Urinary diagnostic indices in acute renal failure: a prospective study. 66 84


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