Primary hyperoxaluria: clinical course, diagnosis, and treatment after kidney failure

Primary hyperoxaluria type 1 (PH1) is a rare autosomal recessive metabolic disorder resulting in the overproduction of plasma oxalate. Although the enzymatic defect is in hepatocyte peroxisomes, uncontrolled levels of oxalate result in calcium oxalate deposition in multiple organs. Because the primary route of elimination of oxalate is renal excretion, high levels are found in urine, which results in supersaturation and crystal nucleation. Patients typically present with recurrent nephrolithiasis and nephrocalcinosis. If not diagnosed early, end-stage renal disease (ESRD) and systemic calcium oxalate deposition can occur. Once ESRD develops, intensive dialysis therapy is unable to keep pace with the high oxalate production, and the preferred therapeutic intervention is combined kidney-liver transplantation. Here, we report a young man with a history of recurrent nephrolithiasis who presented to us with ESRD and subsequently developed manifestations of systemic oxalosis. The diagnosis of PH1 must be considered in the differential diagnosis of patients presenting with ESRD with a history of recurrent nephrolithiasis. The diagnosis of PH1 is more challenging in patients with ESRD, for whom urinary oxalate levels are often normal or only modestly increased because of decreased glomerular filtration, and recurrent nephrolithiasis is no longer the dominant clinical feature.