Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0035078 (renal failure)
 31,970 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Primary hyperoxaluria type 1 (PH1) is caused by deficiency of peroxisomal alanine-glyoxylate aminotransferase which is in humans exclusively expressed in liver cells. The disease is inherited as an autosomal recessive trait, and initial symptoms usually occur in early childhood. Up to the age of 25 years, 90% of the patients are symptomatic, and many patients develop end-stage renal failure. Pronounced medical care is necessary in PH1 patients to prevent generalized oxalosis with complications due to bone disease and peripheral gangrene. The rather short survival of patients on hemodialysis is caused by sudden arrhythmias and heart block. As no dialysis procedure is able to remove the daily produced oxalate, early transplantation is mandatory. Our 45-year-old patient is remarkable on the basis of the late manifestations of PH1. The diagnosis was delayed by unspecific symptoms of nephrolithiasis with recurrent pyelonephritis. Clinical course and diagnostic cornerstones of primary hyperoxaluria are outlined. The principles of conservative treatment and experiences with dialysis and transplantation are discussed.
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PMID:Primary hyperoxaluria type 1 causing end-stage renal disease in a 45-year-old patient. 1117 30

We report herein a domino orthotopic liver transplantation (LT), from a 38-year-old woman undergoing liver-kidney transplantation (LKT) for primary hyperoxaluria type I (PH1) to a recipient with cirrhosis and hepatocellular carcinoma. Delayed onset of PH1 and renal failure and 10% residual alanine-glyoxylate aminotransferase (AGT) activity in domino liver justified its use for domino procedure. The clinical course after LKT was similar to that described in other series, including ours. Renal function started promptly and maintained despite sustained hyperoxaluria from dissolution of oxalotic deposits. Conversely, the domino recipient manifested severe hyperoxaluria and developed nephrolithiasis and renal insufficiency with rapid progression over 2 months. A new LT resulted in slow decrease of oxaluria and improvement of renal function. Therefore, PH1 behaved quite differently in these two patients, leading us to conclude that domino LT using livers from PH1 patients should be considered very carefully, only as a bridge to definitive LT in recipients with critical clinical conditions.
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PMID:Severe course of primary hyperoxaluria and renal failure after domino hepatic transplantation. 1609 18

Genetic disorders of mineral metabolism cause urolithiasis, renal disease, and osteodystrophy. Most are rare, such that the full spectrum of clinical expression is difficult to appreciate. Diagnosis is further complicated by overlap of clinical features. Dent's disease and primary hyperoxaluria, inherited causes of calcium urolithiasis, are both associated with nephrocalcinosis and urolithiasis in early childhood and renal failure that can occur at any age but is seen more often in adulthood. Bone disease is an inconsistent feature of each. Dent's disease is caused by mutations of the CLCN-5 gene with impaired kidney-specific CLC-5 chloride channel expression in the proximal tubule, thick ascending limb of Henle, and the collecting ducts. Resulting hypercalciuria and proximal tubule dysfunction, including phosphate wasting, are primarily responsible for the clinical manifestations. Low-molecular-weight proteinuria is characteristic. Definitive diagnosis is made by DNA mutation analysis. Primary hyperoxaluria, type I, is due to mutations of the AGXT gene leading to deficient hepatic alanine-glyoxylate aminotransferase activity. Marked overproduction of oxalate by hepatic cells results in the hyperoxaluria responsible for clinical features. Definitive diagnosis is by liver biopsy with measurement of enzyme activity, with DNA mutation analysis used increasingly as mutations and their frequency are defined. These disorders of calcium urolithiasis illustrate the value of molecular medicine for diagnosis and the promise it provides for innovative and more effective future treatments.
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PMID:Stones, bones, and heredity. 1680 Nov 62

Mutations in the alanine-glyoxylate aminotransferase gene (AGXT) are responsible for primary hyperoxaluria type I, a rare disease characterized by excessive hepatic oxalate production that leads to renal failure. A deeper understanding of the changes in the metabolic pathways secondary to the lack of AGXT expression is needed in order to explore substrate depletion as a therapeutic strategy to limit oxalate production in primary hyperoxaluria type I. We have developed an Agxt knockout (AgxtKO) mouse that reproduces some key features of primary hyperoxaluria type I. To improve our understanding of the metabolic adjustments subsequent to AGXT deficiency, we performed a proteomic analysis of the changes in expression levels of various subcellular fractions of liver and kidney metabolism linked to the lack of AGXT. In this article, we report specific changes in the liver and kidney proteome of AgxtKO mice that point to significant variations in gluconeogenesis, glycolysis and fatty acid pathways.
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PMID:Differential expression of liver and kidney proteins in a mouse model for primary hyperoxaluria type I. 2097 70

Primary hyperoxaluria type I (PH1) is an inborn error of metabolism caused by deficiency of the hepatic enzyme alanine-glyoxylate aminotransferase (AGXT or AGT) which leads to overproduction of oxalate by the liver and subsequent urolithiasis and renal failure. The current therapy largely depends on liver transplantation, which is associated with significant morbidity and mortality. To explore an alternative treatment, we used somatic gene transfer in a mouse genetic model for PH1 (Agxt1KO). Recombinant adeno-associated virus (AAV) vectors containing the human AGXT complementary DNA (cDNA) were pseudotyped with capsids from either serotype 8 or 5, and delivered to the livers of Agxt1KO mice via the tail vein. Both AAV8-AGXT and AAV5-AGXT vectors were able to reduce oxaluria to normal levels. In addition, treated mice showed blunted increase of oxaluria after challenge with ethylene glycol (EG), a glyoxylate precursor. In mice, AGT enzyme activity in whole liver extracts were restored to normal without hepatic toxicity nor immunogenicity for the 50 day follow-up. In summary, this study demonstrates the correction of primary hyperoxaluria in mice treated with either AAV5 or AAV8 vectors.
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PMID:Phenotypic correction of a mouse model for primary hyperoxaluria with adeno-associated virus gene transfer. 2111 25

Primary hyperoxaluria is a genetic disorder in glyoxylate metabolism that leads to systemic overproduction of oxalate. Functional deficiency of alanine-glyoxylate aminotransferase in this disease leads to recurrent nephrolithiasis, nephrocalcinosis, systemic oxalosis, and kidney failure. We present a young woman with end-stage renal disease who received a kidney allograft and experienced early graft failure presumed to be an acute rejection. There was no improvement in kidney function, and she was required hemodialysis. Ultimately, biopsy revealed birefringent calcium oxalate crystals, which raised suspicion of primary hyperoxaluria. Further evaluations including genetic study and metabolic assay confirmed the diagnosis of primary hyperoxaluria type 1. This suggests a screening method for ruling out primary hyperoxaluria in suspected cases, especially before planning for kidney transplantation in patients with end-stage renal disease who have nephrocalcinosis, calcium oxalate calculi, or a family history of primary hyperoxaluria.
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PMID:Recurrence of primary hyperoxaluria after kidney transplantation. 2205 78

Primary hyperoxaluria type 1 (PH1) and type 2 (PH2) are rare genetic diseases that result from deficiencies in glyoxylate metabolism. The increased oxalate synthesis that occurs can lead to kidney stone formation, deposition of calcium oxalate in the kidney and other tissues, and renal failure. Hydroxyproline (Hyp) catabolism, which occurs mainly in the liver and kidney, is a prominent source of glyoxylate and could account for a significant portion of the oxalate produced in PH. To determine the sensitivity of mouse models of PH1 and PH2 to Hyp-derived oxalate, animals were fed diets containing 1% Hyp. Urinary excretions of glycolate and oxalate were used to monitor Hyp catabolism and the kidneys were examined to assess pathological changes. Both strains of knockout (KO) mice excreted more oxalate than wild-type (WT) animals with Hyp feeding. After 4 wk of Hyp feeding, all mice deficient in glyoxylate reductase/hydroxypyruvate reductase (GRHPR KO) developed severe nephrocalcinosis in contrast to animals deficient in alanine-glyoxylate aminotransferase (AGXT KO) where nephrocalcinosis was milder and with a lower frequency. Plasma cystatin C measurements over 4-wk Hyp feeding indicated no significant loss of renal function in WT and AGXT KO animals, and significant and severe loss of renal function in GRHPR KO animals after 2 and 4 wk, respectively. These data suggest that GRHPR activity may be vital in the kidney for limiting the conversion of Hyp-derived glyoxylate to oxalate. As Hyp catabolism may make a major contribution to the oxalate produced in PH patients, Hyp feeding in these mouse models should be useful in understanding the mechanisms associated with calcium oxalate deposition in the kidney.
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PMID:Hydroxyproline metabolism in mouse models of primary hyperoxaluria. 2249 66

Type 1 primary hyperoxaluria is a genetic disorder caused by deficiency of the liver-specific peroxisomal enzyme alanine-glyoxylate aminotransferase. This enzyme deficiency leads to excess oxalate production and deposition of calcium oxalate salts, resulting in kidney failure and systemic oxalosis. Aside from combined liver/kidney transplantation, no curative treatment exists. Various strategies for optimizing dialysis treatment have been evaluated, but neither conventional hemodialysis nor peritoneal dialysis can keep pace with oxalate production in this patient population. In this report, we describe a patient with end-stage renal disease from type 1 primary hyperoxaluria managed with nocturnal home hemodialysis. Performing hemodialysis 8-10 hours each night with blood flow of 350 mL/min and total dialysate volume of 60 L, she has maintained pre- and postdialysis serum oxalate levels at or below the level of supersaturation. We also review published literature regarding oxalate removal in various modalities of dialysis in patients with type 1 primary hyperoxaluria. In our patient, nocturnal hemodialysis has controlled serum oxalate levels better than conventional hemodialysis therapies. Home nocturnal hemodialysis should be considered an option for management of patients with end-stage renal disease from type 1 hyperoxaluria who are awaiting transplantation.
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PMID:Nocturnal home hemodialysis for a patient with type 1 hyperoxaluria. 2383 Aug

Primary hyperoxaluria (PH) occurs due to an autosomal recessive hereditary disorder of the metabolism of glyoxylate, which causes excessive oxalate production. The most frequent and serious disorder is due to enzyme deficit of alanine-glyoxylate aminotransferase (PH type I) specific to hepatic peroxisome. As oxalate is not metabolised in humans and is excreted through the kidneys, the kidney is the first organ affected, causing recurrent lithiasis, nephrocalcinosis and early renal failure. With advance of renal failure, particularly in patients on haemodialysis (HD), calcium oxalate is massively deposited in tissues, which is known as oxalosis. Diagnosis is based on family history, the presence of urolithiasis and/or nephrocalcinosis, hyperoxaluria, oxalate deposits in tissue forming granulomas, molecular analysis of DNA and enzyme analysis if applicable. High diagnostic suspicion is required; therefore, unfortunately, in many cases it is diagnosed after its recurrence following kidney transplantation. Conservative management of this disease (high liquid intake, pyridoxine and crystallisation inhibitors) needs to be adopted early in order to delay kidney damage. Treatment by dialysis is ineffective in treating excess oxalate. After the kidney transplant, we normally observe a rapid appearance of oxalate deposits in the graft and the results of this technique are discouraging, with very few exceptions. Pre-emptive liver transplantation, or simultaneous liver and kidney transplants when there is already irreversible damage to the kidney, is the treatment of choice to treat the underlying disease and suppress oxalate overproduction. Given its condition as a rare disease and its genetic and clinical heterogeneity, it is not possible to gain evidence through randomised clinical trials. As a result, the recommendations are established by groups of experts based on publications of renowned scientific rigour. In this regard, a group of European experts (OxalEurope) has drawn up recommendations for diagnosis and treatment, which were published in 2012.
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PMID:Primary hyperoxaluria. 2479 59

Primary hyperoxaluria type-1 (PH1) is a rare inherited autosomal recessive disorder in which a deficiency of the hepatic enzyme alanine-glyoxylate aminotransferase leads to endogenous oxalate overproduction, renal failure, systemic oxalate deposition and death. As hemodialysis provides insufficient oxalate clearance, patients ultimately require both liver and kidney transplantation for correction of the metabolic abnormality and oxalate excretion. Herein, we describe a young adult male with end-stage renal disease and systemic oxalosis causing progressive disabling multi-organ dysfunction while awaiting transplantation. We review the literature regarding liver-kidney transplantation and suggest that for patients with PH1, a standardized assessment of organ dysfunction and functional impairment may improve identification of patients requiring urgent transplantation thereby reducing the morbidity and mortality that can occur with delayed transplantation.
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PMID:Liver-kidney transplantation in primary hyperoxaluria type-1: case report and literature review. 2501 5


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