Figure 1111

Sequential biopsies of a transplanted kidney documenting progressive recurrence of renal oxalosis. This patient with primary hyperoxaluria type I received renal transplantation, without liver transplantation, at 24 years of age. Panels A-D show tissue stained with hematoxylin and eosin. Panels A-C show specimens viewed by polarization microscopy, all at the same low-power magnification, from biopsies taken after transplantation within the first year (A), third year (B),

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FIGURE 11-11 (Continued)

and fifth year (C), following renal transplantation. Deposition of oxalate crystals became progressively more severe with time, and the kidney failed after 5 years. Panel D illustrates a higher-power magnification, without polarization, of the biopsy at 5 years, showing a radial array of oxalate crystals and phagocytosis of small crystals by multinucleated giant cells (E).

Conservative treatment of PH1 is of limited efficacy. Dietary restriction has little effect on the course of the disease. High-dose pyridoxine should be tried in all patients, but many patients do not respond. Strategies to prevent calcium oxalate stone formation include a high fluid intake (recommended in all patients), magnesium oxide (because magnesium increases the solubility of calcium oxalate salts), and inorganic phosphate. Lithotripsy or surgery may be necessary but do not alter the progression of nephrocalcinosis [12,13].

Hemodialysis is superior to peritoneal dialysis in its ability to remove oxalate, but neither one is able to maintain a rate of oxalate removal sufficient to keep up with the production rate in patients with PH1. Once end-stage renal disease develops, hemo-dialysis does not prevent the progression of systemic oxalosis. In some patients, renal transplantation accompanied by an aggressive program of management has been followed by a good outcome for years [14]. However, oxalosis often recurs in the transplanted kidney, particularly if any degree of renal insufficiency develops for any reason. In recent years, liver transplantation has been used with success, with or without renal transplantation, and offers the prospect of definitive cure. Results of liver transplantation are best in patients who have not yet developed significant renal insufficiency [12]. (Courtesy of Paul Shanley, MD.)

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