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Query: UMLS:C0020500 (hyperoxaluria)
 912 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Primary hyperoxaluria type I (PH I) is characterized by an excessive endogenous production and excretion of oxalic and glycolic acid. Prognosis of this "inborn error of metabolism" is not favorable due to calcium-oxalate depositions in kidney and other organs. Vitamin B6 administration and/or renal transplantation can greatly improve the prognosis, as reported in literature. In this article our experience with 5 patients with vitamin B6 resistant hyperoxaluria is reported. Symptomatology and progression of the primary disease are described. The results of treatment interfering with oxalate production and calcium-oxalate crystallization are given. Three patients underwent renal replacement therapy. In these, oxalosis developed during hemodialysis and progressed following transplantation; a disabling bone disease was the most severe complication. Outcome of transplantation was disappointing. In two out of three patients, there was recurrence of the primary disease in the graft. In only one of them long-term graft function was satisfying. However, even this good function could not prevent disabling symptoms of oxalosis. Therefore, evaluation of the results of transplantation should not only include data related to graft function and survival, but also the complications due to calcium-oxalate depositions in various organs. To prevent oxalosis, kidney transplantation should be performed before end stage renal disease is achieved in patients with vitamin B6 resistant PH I.
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PMID:Vitamin B6 resistant primary hyperoxaluria type I. Report of 5 cases. 270 72

Primary hyperoxaluria (PH) type 1 and type 2 are autosomal recessive defects of oxalate metabolism resulting from glyoxylate accumulation which occurs by two distinct pathways. PH1 is associated to glycolic aciduria; PH2 to L-glyceric aciduria. Because hyperoxaluria leads to nephrolithiasis or nephrocalcinosis in both, they can be differentiated only through detection of the associated acidurias. However, glycolate and L-glycerate assays are not widely available and, in the setting of ESRF, diagnosis is hampered by a number of misleading events. At any stage of the disease diagnosis is crucial because there are differences between the two forms in clinical behaviour, long-term prognosis, and treatment. In this paper we outline diagnostic criteria for identification of PH2 in two patients, one with maintained renal function and one with ESRF on CPD, based on the use of a novel HPLC assay of L-glycerate in different body fluids. With the routine application of this procedure PH2 has been identified in two of 23 patients fulfilling criteria for diagnosis of PH. This suggests that the type 2 variant of PH may occur more frequently than so far suspected, and should be tested for even in the setting of ESRF.
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PMID:Detection of primary hyperoxaluria type 2 (L-glyceric aciduria) in patients with maintained renal function or end-stage renal failure. 853 30

Primary hyperoxaluria type I (PHI) is a cause of end-stage renal disease in young people. It is caused by deficient activity of hepatic peroxisomal alanine:glyoxylate aminotransferase (AGT), which results in hyperoxalemia and hyperoxaluria. The consequent urolithiasis and nephrocalcinosis result in renal impairment, with further reduction in oxalate excretion and eventual systemic oxalosis. Historically, renal transplantation has yielded very poor results in these patients because of recurrent oxalosis of the graft. Within the last 10 years, combined hepatorenal transplantation has been successfully applied, simultaneously correcting the metabolic lesion in the liver and replacing the damaged kidneys. It has, however, become apparent that medical therapy with vigorous hydration, inhibitors of stone formation and pyridoxine (AGT co-factor), may be successful at delaying, and occasionally in preventing, urolithiasis in some hyperoxaluric patients, particularly those whose hyperoxaluria is reduced by pyridoxine. This, together with intensive perioperative management and modern surgical methods of stone management such as lithotripsy, laser or ultrasound stone fragmentation, and percutaneous nephrolithotomy, means that renal transplantation alone may be feasible in selected patients. We describe a patient with PHI with clinical and biochemical evidence of significant residual AGT activity who underwent a successful live-related renal transplantation with excellent renal function and no stone recurrence 1 year posttransplantation. The appropriate transplantation strategies for these complex patients are discussed and include isolated renal transplantation for those patients who are without significant systemic oxalosis and have evidence of residual AGT activity.
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PMID:Selective renal transplantation in primary hyperoxaluria type 1. 865 Dec 56

The aim of this study was to assess the frequency and clinical implications of a recurrence of the original renal disease in children after kidney transplantation. Thus, the records of patients with immunological and metabolic diseases transplanted between 1970 and 1994 were retrospectively analyzed. There were 113 renal transplantations in 99 patients, who had the following original diseases: focal segmental glomerulosclerosis (FSGS), membrano-proliferative glomerulonephritis type I and type II (MPGN I, II), Henoch-Schoenlein nephritis, IgA-nephropathy, hemolytic uremic syndrome (HUS) and hyperoxaluria type I (PH I) and other rare diseases. Recurrences were observed in FSGS, MPGN II, HUS and PH I but not in the other diseases. In FSGS, the recurrence rate was 20% with graft failure in 5 of 6 grafts. No specific risk factors for recurrent FSGS could be determined. In MPGN II, the recurrence was 60% but the loss of grafts occurred at the same rate as in the non-recurrence group. In HUS, recurrence was seen in 4 out of 24 renal grafts (16.6%) with subsequent graft loss in all cases. All cases had suffered from an atypical HUS. PH I recurred in 4 of 5 allografts with graft loss in all patients. The remaining graft was transplanted after a liver transplantation and graft function was well preserved for 4 years. We confirm that the risk of recurrence with loss of the graft is high in a certain group of renal diseases. In these the indication for transplantation, particularly with living related donor kidneys, needs special evaluation. A better understanding of the pathomechanism of the diseases should lead to prevention of recurrence, as in PH I in which a liver transplant is now the primary option.
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PMID:Recurrence of renal disease after kidney transplantation in children: 24 years of experience in a single center. 952 77

Primary hyperoxaluria (PH) is a heterogeneous disease with a variable age of onset and a variable progression into kidney failure. Early diagnosis is mandatory to avoid the damaging effects of systemic calcium oxalate deposition. In 1997, we initiated a nationwide survey of American nephrologists to ascertain epidemiological data and current practices. PH was reported in only 102 patients, with PH I in 79 and PH II in 9; 14 patients were not classified. Most patients were Caucasian (84%). Main symptoms at diagnosis were urolithiasis (54.4%) and nephrocalcinosis (30%). A significant delay of diagnosis was seen in 42% of patients and 30% of patients were diagnosed only at end-stage renal disease (ESRD). Diagnosis was usually based on history and urinary oxalate excretion. Glycolate and l-glyceric acid excretion were rarely determined. To determine the enzyme defect, a liver biopsy was performed in 40%. Even at ESRD, only 56% of patients received an adequate diagnostic work-up. Half of the patients showed 'good' or 'fair' pyridoxine sensitivity. In addition to B(6), most patients received either citrate or orthophosphate. Kidney transplantation (KTx) failed in 19 of 32 transplants ( n=27 patients) and was due to recurrent oxalosis in 8 transplants. Liver Tx was performed after KTx in 5 patients (1 patient died). Combined liver-kidney Tx in 21 patients (in 9 patients after failure of KTx) achieved good organ function in 13 patients; 7 patients, however, died shortly after transplantation. In conclusion, the time between first symptom and diagnosis of PH must be minimized, and the diagnostic procedures have to be improved. The cases of unclassified hyperoxaluria suggest the possibility of additional type(s) of PH. As isolated KTx failed in 59% of patients, combined liver-kidney Tx seems to be the better choice in place of isolated KTx as the primary transplant procedure.
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PMID:A United States survey on diagnosis, treatment, and outcome of primary hyperoxaluria. 1292 Jun 26

Primary hyperoxaluria type I is a rare inborn error of metabolism caused by a deficiency of a liver-specific peroxisomal enzyme. It manifests by increased oxalate production that ultimately results in kidney failure, due to urolithiasis and nephrocalcinosis, and finally induces systemic oxalosis and risk of premature death. Primary hyperoxaluria type 2 is mainly responsible of urolithiasis. Enteric hyperoxaluria is a commonly seen adverse event of Crohn disease or after extensive intestinal resection. These affections represent the main etiologies of massive hyperoxaluria. If not recognized very soon and adequately treated, these conditions can progress rapidly to end stage renal failure.
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PMID:[Massive hyperoxaluria]. 1549 71

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

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 type I is a rare inherited disease that presents a disturbed metabolism of glyoxylate. Consequently, patients suffer from hyperoxaluria, leading to renal failure and subsequent skeletal calcium oxalate deposition. Areas with high concentrations of calcium oxalate, so-called dense metaphyseal bands, are at risk for pathological fracturing. The primary disease is treated by combined liver-kidney transplantation, although pathological fracturing also occurs in the posttransplant period. In the current case, we present a 3-year-old boy with a pathological fracture of his right femur, 2 years after liver-kidney transplantation. We opted for a conservative regime, leading to good fracture healing. As there are limited data in the literature regarding treatment of fractures in these patients, it is important to notify the outcome of conservative treatment of pathological fractures in patients with primary hyperoxaluria type I.
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PMID:Conservative treatment of a pathological fracture in a 3-year-old boy with primary hyperoxaluria type I. 2221 25

In the present paper we report the oral findings of a patient who was diagnosed with hyperoxaluria. Hyperoxalurias can basically be classified as primary and secondary, with the first being inborn errors of metabolism and the second a result of excessive oxalate intake. Primary hyperoxalurias form a rare group of metabolic diseases that are inherited in the autosomal recessive fashion. The affected genes code for specific hepatic enzymes that are involved in glyoxylate metabolism and their deficiency results in overproduction of oxalate. Two different types are described: Primary hyperoxaluria type I results from a deficiency of peroxisomal enzyme alanine-glyoxylate aminotransferase and the more rare type II from a deficiency of cytosolic enzyme D-glycerate dehydrogenase. Since oxalate is primarily excreted through the kidneys, abnormally high concentration of oxalate in the urine occurs. This can in turn result in recurrent kidney stones and parenchymal renal damage and end-stage renal disease (ESRD). Inability to further excrete oxalate through the kidneys leads to its deposition in various organs (oxalosis). Several oral findings have been described in patients with oxalosis, most important of whose are bone resorption in the jaws, external root resorption and rapidly progressive dental mobility, as well as dental pain associated with deposition of oxalate in the dentine and the pulp.
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PMID:Oral findings associated with primary hyperoxaluria type I. 2241 69


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