Recurrent Nephrolithiasis Causing Kidney Failure.

A 56-year-old woman with diabetes mellitus and kidney failure treated by kidney transplantation 3 months prior is referred to your clinic for elevated serum creatinine. She gives a personal history of recurrent urinary tract infections in the setting of obstructive uropathy and recurrent nephrolithiasis. Two years ago, she developed kidney failure. Imaging at the time revealed staghorn calculi with left hydroureter (Fig 1). She underwent bilateral ureteral stent placement with some improvement in glomerular filtration rate (GFR); however, she continued to experience progressive GFR decline and required hemodialysis. At the time of planned dialysis initiation, she also underwent bilateral native nephrectomies owing to persistent pain. Pathology was significant for oxalate nephropathy with nephrolithiasis, diffuse interstitial scarring, and focal global glomerulosclerosis with intratubular birefringent calcium oxalate crystal deposits. She denies a family history of kidney disease or nephrolithiasis. After a year of treatment with dialysis, she received a living unrelated kidney transplant. One month after transplantation, she had a kidney biopsy performed for elevated serum creatinine. Kidney pathology was significant for inspissation of refractile oxalate crystals in the tubular lumina and in the cytoplasm of renal tubular cells. She was subsequently hospitalized for hyperkalemia (potassium, 5.9 mEq/L) with a serum bicarbonate of 13.6 mg/dL and serum creatinine of 1.52 mg/dL. Serum creatinine remained stable during