A Successful Approach to Kidney Transplantation in Patients With Enteric (Secondary) Hyperoxaluria.

Background: Enteric hyperoxaluria due to malabsorption may cause chronic oxalate nephropathy and lead to end-stage renal disease. Kidney transplantation is challenging given the risk of recurrent calcium-oxalate deposition and nephrolithiasis.

Methods: We established a protocol to reduce plasma oxalic acid levels peritransplantation based on reduced intake and increased removal of oxalate. The outcomes of 10 kidney transplantation patients using this protocol are reported.

Results: Five patients received a living donor kidney and had immediate graft function. Five received a deceased donor kidney and had immediate (n = 1) or delayed graft function (n = 4). In patients with delayed graft function, the protocol was prolonged after transplantation. In 3 patients, our protocol was reinstituted because of late complications affecting graft function. One patient with high-output stoma and relatively low oxalate levels had lost her first kidney transplant because of recurrent oxalate depositions but now receives intravenous fluid at home on a routine basis 3 times per week to prevent dehydration. Patients are currently between 3 and 32 months after transplantation and all have a stable estimated glomerular filtration rate (mean, 51 ± 21 mL/min per 1.73 m2 ). In 4 of 8 patients who underwent for cause biopsies after transplantation oxalate depositions were found.

Conclusions: This is the first systematic description of kidney transplantation in a cohort of patients with enteric hyperoxaluria. Common complications after kidney transplantation impact long-term transplant function in these patients. With our protocol, kidney transplantation outcomes were favorable in this population with unfavorable transplantation prospects and even previous unsuccessful transplants.