TWO CASES OF PRIMARY OXALOSIS

Long Term Survival on Haemodialysis in Primary Hyperoxaluria

Results of treatment of end-stage renal failure (ESRF) in patients with primary hyperoxaluria have been generally poor, largely due to the inability of any treatment regime to match the endogenous overproduction of oxalate. The severity of the disease varies widely, as reflected by the differences in age at onset of ESRF. This variability may influence the results of treatment of ESRF in these patients. The longest reported survival on haemodialysis of a patient with primary hyperoxaluria is eight and a half years. We report a patient who survived for eleven years on haemodialysis after reaching ESRF due to primary hyperoxaluria, and suggest that this prolonged survival was due to relatively mild disease severity rather than exceptional treatment.

The impact of metaphylaxis of kidney stone disease in the renal function at long term in active kidney stone formers patients

A total of 150 patients were included in the analysis. Through chart review, we estimated glomerular filtration rate in the first visit and, at least, 5 years later. All patients were divided into two groups: (1) metaphylaxis adherents (n = 74) and (2) metaphylaxis non-adherents (n = 76). We followed all patients for at least 5 years. The Scr percentage of patients and GFR <60 mL/min was compared between groups. Variables were compared between groups using t test, χ(2) tests, odds ratios with 95% confidence intervals. There were no differences at baseline between groups. After 5 years of follow-up, GFR was 77.9 mL/min in non-adherent-metaphylaxis group and in the adherent-metaphylaxis group was 87.3 mL/min, with p value of 0.02. After 5 years of follow-up, we had a GFR <60 mL/min in the adherent-metaphylaxis group (4.89 vs. 21.95%) with p value of 0.001 and OR = 5.36; IC-95% = 1.95-14.8. Metaphylaxis of kidney stone disease could prevent chronic kidney disease.

Renal cell osteopontin production is stimulated by calcium oxalate monohydrate crystals

Specific anions in tubular fluid, including uropontin (UP), the urinary form of human osteopontin (OPN), block adhesion to renal tubular cells of the most common crystal in kidney stones, calcium oxalate monohydrate (COM). In this study, monkey renal epithelial cells (BSC-1 line) in monolayer culture constitutively secreted UP into the culture medium. COM crystals added to the medium avidly bound previously secreted UP, reducing its concentration by 46% one hour later. However, the net UP content of cultures after a 24-hour exposure to COM crystals was increased by 18%. Northern blotting showed that the constitutively expressed gene encoding human OPN was maximally stimulated in BSC-1 cells after exposure to COM crystals for 12 hours. Two other calcium-containing crystals, hydroxyapatite and brushite, did not alter OPN gene expression or protein production. OPN mRNA expression was enhanced in canine renal epithelial cells (MDCK line) after exposure to COM crystals for six hours, whereas the constitutive expression of murine OPN mRNA by 3T3 fibroblasts was unchanged. In vivo this glycoprotein could defend the cell against adhesion of crystals in tubular fluid, and/or promote renal interstitial fibrosis in subjects with heavy crystalluria.

Initial manifestation of primary hyperoxaluria type I in adults-- recognition, diagnosis, and management

Primary hyperoxaluria type I may initially manifest as urolithiasis, renal insufficiency, or symptoms of systemic oxalosis. This hereditary disorder was fatal until effective therapies evolved during the past two decades. Difficulty in recognizing and diagnosing this disorder in adults is illustrated in a report of a patient eventually restored to good health by high-flux dialysis and combined renal and hepatic transplantation. I explore the molecular processes of the genetic defect and discuss clinical indicators of primary hyperoxaluria type I, manifestations of oxalosis, the pathogenesis of chronic oxalate nephropathy, and the diagnosis and management of this disease.

Calcium oxalate monohydrate crystals stimulate gene expression in renal epithelial cells

Primary or secondary hyperoxaluria is associated with calcium oxalate nephrolithiasis, interstitial fibrosis and progressive renal insufficiency. Monolayer cultures of nontransformed monkey kidney epithelial cells (BSC-1 line) and calcium oxalate monohydrate (COM) crystals were used as a model system to study cell responses to crystal interactions that might occur in the nephrons of patients during periods of hyperoxaluria. To determine if COM crystals signal a change in gene expression, Northern blots were prepared from total renal cellular RNA after the cells were exposed to crystals. The immediate early genes c-myc, EGR-1, and Nur-77 were induced at one hour. At two to six hours stimulated expression of the genes encoding plasminogen activator inhibitor (PAI-1) and platelet-derived growth factor (PDGF)-A chain was detected, but constitutive expression of urokinase-type plasminogen activator (u-PA) was not altered. Expression of connective tissue growth factor (CTGF) was induced at one hour and persisted up to 24 hours. The stimulation of gene expression by COM crystals was relatively crystal- and renal cell-type specific. Thus the interaction of kidney epithelial cells with COM crystals alters expression of genes that encode three classes of proteins: transcriptional activators, a regulator of extracellular matrix (ECM), and growth factors. Activation of PAI-1 gene expression without a change in u-PA favors accumulation of ECM proteins, as does increased expression of PDGF and CTGF which can also stimulate fibroblast proliferation in a paracrine manner. These results suggest that COM crystal-mediated stimulation of specific genes in renal tubular cells may contribute to the development of interstitial fibrosis in hyperoxaluric states.

Histopathological occurrence and characterisation of calcium oxalate: a review

Oxalosis is the histological manifestation of a number of diverse clinicopathological states involving abnormalities of both endogenous and exogenous oxalate. Crystalline deposits of calcium oxalate, usually first detected by their birefringence, may be characterised by a combination of their physical and tinctorial properties.

Crystals in brain and meninges in primary hyperoxaluria and oxalosis

A case of primary hyperoxaluria and oxalosis with chronic renal failure, crystalline myocarditis, and disseminated calcium oxalate crystal deposition in various tissues including the brain and meninges is described. Deposition of crystals in brain and meninges is exceptionally rare in primary oxalosis.

Peripheral neuropathy in oxalosis. A case report with electron microscopic observations

A 61 year old man had chronic renal failure because of oxaluria and renal calculi. Two years before death, while on hemodialysis, he developed severe progressive peripheral neuropathy. At autopsy calcium oxalate crystals were found in the peripheral nerves and other tissues. Nerve lesions included segmental demyelination, axonal degeneration and crystalline deposits within the myelin sheath. Ultrastructurally there were foci of osmiophilic granular material within myelin lamellae and endoneurium, and pleomorphic lamellar bodies in the perinuclear Schwann cell cytoplasm. It is probable that chronic hemodialysis favors the deposition of oxalate in the Schwann cells and the development of neuropathy in patients with primary hyperoxaluria and renal failure.

Classification of the secondary cardiomyopathies. The pathologist's view

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Primary oxalosis of the heart: a cause of heart block

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