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

From 1990 to 2000, we performed eight liver-kidney transplants in eight children, aged 1-16 years, with end-stage renal failure (ESRF) due to primary hyperoxaluria (PH1). The duration of dialysis before transplantation ranged from 2 to 42 months (mean 14 months) and was <1 year in four patients. Only the first patient underwent postoperative hemodialysis; in the other five, we chose to induce maximal diuresis from the first hours with intravenous and intragastric hyperhydration (> or =3 l/m2 per day). High water intake with nocturnal tube hydration was maintained for 6 months to 5 years, as long as oxaluria exceeded 0.5 mmol/day. A quadruple sequential immunosuppressive regimen was used. Two patients died during liver graft surgery. The other six patients are alive and well, with a mean follow-up of 7.4 years (range 5-11 years). Patient and graft survival is 75% at 5 years. At latest follow-up, liver tests were normal in all six patients; creatinine clearance ranged from 55 to 95 ml/min per 1.73 m2 (mean=74). Oxaluria was lower than 0.4 mmol/day in all patients (mean=0.22). The six patients underwent 15 renal biopsies, 1-11 years after transplantation. Chronic transplant nephropathy was present in four patients and mild cyclosporin nephrotoxicity in another. No oxalate crystals were seen and repeat ultrasonography has been consistently normal in all patients. The three patients with bone oxalosis showed progressive complete healing of bone lesions. All six children or adolescents now live a normal life. From this series, we conclude that early combined liver-kidney transplantation is the treatment of choice for children with ESRF due to primary hyperoxaluria.
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PMID:Long term results of liver-kidney transplantation in children with primary hyperoxaluria. 1179 78

Few data have been published on the course of oxalosis cardiomyopathy after combined liver and kidney transplantation in hyperoxaluria patients with myocardial involvement. We report the case of a primary hyperoxaluria type 1 patient with renal failure who developed end-stage cardiomyopathy. Left venticulography showed severe diffuse hypokinesia and left ventricular ejection fraction was calculated at 12%. Endomyocardial biopsy demonstrated platelike calcium oxalate crystals within the myocardium and the connective tissue, and mild perivascular fibrosis. The patient was first considered for combined liver-heart-kidney transplantation, but as his cardiac function improved slightly with an intensive dialysis program, combined liver and kidney transplantation was performed. Normal cardiac function was demonstrated at 1-year follow-up, and comparative endomyocardial biopsy showed regression of the myocardial oxalate deposits. This case adds stronger clinical, hemodynamic, and histopathological evidence that severe oxalosis cardiomyopathy may be reversed after combined liver and kidney transplantation.
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PMID:Reversal of oxalosis cardiomyopathy after combined liver and kidney transplantation. 1187 14

We report on a middle-aged man with end-stage renal failure apparently secondary to recurrent renal stones. He developed systemic oxalosis soon after commencing dialysis. The diagnosis of primary hyperoxaluria type 1 was supported by the finding of high dialysate glycolate excretion. The patient subsequently received an isolated cadaveric renal transplant, but the outcome was a rapid recurrence of oxalosis and early graft failure. Although isolated liver or renal transplantation in addition to various adjuvant measures may be considered in the early stage, combined liver-kidney transplantation remains the only definitive therapy for a patient with end-stage renal failure and systemic oxalosis due to hyperoxaluria type 1. This case illustrates the possible late presentation of primary hyperoxaluria type 1 and the poor outcome with isolated renal transplantation after the development of systemic oxalosis. One should thus have a high index of suspicion in patients with recurrent renal stones of this rare, but nevertheless important, entity.
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PMID:Primary hyperoxaluria: a rare but important cause of nephrolithiasis. 1205 67

Hyperoxaluria leads to increased calcium oxalate supersaturation and calcium oxalate stone formation. Excess oxalate can arise from endogenous overproduction as in primary hyperoxaluria or from dietary sources. In the last 15 years great strides have been made in the diagnosis and treatment of primary hyperoxaluria. However options still seem limited in treating the mild hyperoxaluria found in many stone formers. Inadequate knowledge of food oxalate content, the effect of dietary oxalate precursors on oxalate excretion, and the factors affecting handling of oxalate by the intestine prevent development of rational therapies for treatment of hyperoxaluria. Recent studies of oxalate degrading bacteria and renewed interest in the role of diet calcium in oxalate absorption may lead to better therapeutic strategies for hyperoxaluric calcium nephrolithiasis.
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PMID:Hyperoxaluric calcium nephrolithiasis. 1247 39

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

Secondary hyperoxaluria is due either to increased intestinal oxalate absorption or to excessive dietary oxalate intake. Certain intestinal diseases like short bowel syndrome, chronic inflammatory bowel disease or cystic fibrosis and other malabsorption syndromes are known to increase the risk of secondary hyperoxaluria. Although the urinary oxalate excretion is usually lower than in primary hyperoxaluria, it may still lead to significant morbidity by recurrent urolithiasis or progressive nephrocalcinosis. A clear distinction between primary and secondary hyperoxalurias is important. As correct classification may be difficult, appropriate diagnostic tools are needed to delineate the metabolic background as a basis for optimal treatment. We developed an individual approach for the evaluation of patients with suspected secondary hyperoxaluria. First, 24 h urines are examined repeatedly for lithogenic (e.g. calcium, oxalate, uric acid) and stone-inhibitory (e.g. citrate, magnesium) substances, and the patients are asked to fill in a dietary survey form. Urinary saturation is calculated using the computer based program EQUIL2, and the BONN-Risk-index is determined. The measurement of plasma oxalate and of urinary glycolate helps to distinguish between primary and secondary hyperoxalurias. If secondary hyperoxaluria is suspected, the stool is examined for Oxalobacter formigenes, an intestinal oxalate degrading bacterium, as lack or absence may lead to increased intestinal oxalate absorption. The last diagnostic step is to study the intestinal oxalate absorption using [13C2]oxalate. Depending on the results, various therapeutic options are available: 1) a diet low in oxalate, but normal or high in calcium, 2) a high fluid intake (>1.5 L/m2/d), 3) medications to increase the urinary solubility, 4) specific therapeutic measures in patients with malabsorption syndromes, depending on the underlying pathology, and 5) intestinal recolonization of Oxalobacter formigenes or the treatment with other oxalate degrading bacteria.
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PMID:Diagnostic and therapeutic approaches in patients with secondary hyperoxaluria. 1295 11

We report a case which demonstrates the disastrous consequences of late diagnosis of hyperoxaluria in a 24-year-old woman with nephrocalcinosis, a staghorn calculus and recurrent urinary tract infections. Her initial management at another hospital included multiple percutaneous nephrostomies and lithropsies. Metabolic screening was not undertaken. Hyperoxaluria was finally diagnosed by elevated urine oxalate (1.235 mmol/24 h) and renal biopsy, by which time there was already significant reduction of renal function. A diagnosis of hyperoxaluria type I was confirmed by liver biopsy. Despite starting pyridoxine and crystallization inhibitors, her renal function deteriorated, requiring hemodialysis and she was referred for combined liver-renal transplantation. Clinical clues of primary hyperoxaluria type I are a positive family history or presentation with severe renal stones at an unusually early age. Irrespective of the above, all patients with first presentation of renal calculi should undergo metabolic screening, including urine oxalate.
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PMID:Always look beyond the stones: hyperoxaluria overlooked. 1526 15

Crystalluria is a marker of urine supersaturation present in both normal and pathological conditions. Indeed, nature and characteristics of the spontaneous crystalluria are of clinical interest for detecting and following biological disorders involved in renal diseases. Method. Crystalluria examination should preferably be performed on first morning urine or fresh fasting voiding samples by polarised microscopy in a Malassez cell. Urine samples must be stored at 37 degrees C or at room temperature and examined within two hours following voiding. Results and discussion. Crystalluria should be interpreted according to various criteria: 1) chemical nature of crystals for abnormal crystals such as struvite, ammonium urate, cystine, dihydroxyadenine, xanthine or drugs; 2) crystalline phase of common chemical species as calcium oxalates, calcium phosphates and uric acids; 3) crystal morphology (calcium oxalates); 4) crystal size (calcium oxalates); 5) crystal abundance (calcium oxalates, calcium phosphates, uric acids, cystine); 6) crystal aggregation (calcium oxalates); 7) frequency of crystalluria assessed on serial first morning urine samples, a very useful tool for long-term surveillance of patients. Within calcium oxalate crystalluria, presence of whewellite is a marker of elevated oxalate concentration (urine oxalate > 0.3 mmol/L); a crystal number > 200/mm 3 is highly suggestive of heavy hyperoxaluria of genetic or absorptive origin. Predominant weddellite crystalluria is most often indicative of an excessive urine calcium concentration (> 3.8 mmol/L); a dodecahedric aspect of the crystals is a marker for heavy hypercalciuria (> 6 mmol/L) while an increased crystal size (>or= 35 microm) is indicative of simultaneous hypercalciuria and hyperoxaluria. Calculation of the global crystal volume, especially when applied to calcium oxalates or cystine, is a clinically useful tool for the monitoring of patients suffering from primary hyperoxaluria or cystinuria. Lastly, presence of crystalluria in more than 50% of serial first voided morning urine samples is in our experience the most reliable biological marker for detecting the risk of stone recurrence in lithiasic patients. Conclusion. Crystalluria examination is an essential laboratory test for detecting and following pathological conditions, which may induce renal stone disease or alter kidney function due to urine crystals.
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PMID:[Clinical value of crystalluria study]. 1529 32

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

Acute renal failure is a major complication in patients with increased oxalate serum concentration. To describe the metabolic mechanisms of oxalate-induced glomerular and tubular damage, we report a case of ethylene glycol intoxication as well as a case of xylitol infusion in a patient with previously unknown primary hyperoxaluria type 1. Both patients presented with acute renal failure associated with histologically proven renal oxalate accumulation. This excessive oxalate overloading resulted from elimination and metabolization of ethylene glycol or xylitol. Thus, key enzymes in the elimination pathway of these substances represent targets for pharmacological treatment. Simultaneous hemodialysis is often necessary to reduce oxalate serum concentration. Whereas renal function of the ethylene glycol-poisoned patient recovered, the second patient who received xylitol infusion required chronic hemodialysis due to the unmasked hyperoxaluria type 1. Our cases demonstrate that patients with excessive endogenous oxalate generation are at high risk to develop acute renal failure. Therefore, to prevent end-stage renal failure in these patients, important clinical factors should be considered as indicators for the underlying cause: history of alcohol abuse and severe high anion gap acidosis for ethylene glycol intoxication or history of long-lasting parenteral nutrition for xylitol-associated acute renal failure.
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PMID:Ethylene glycol intoxication and xylitol infusion--metabolic steps of oxalate-induced acute renal failure. 1578 25


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