Simultaneous or sequential kidney-liver transplantation in primary hyperoxaluria

Primary hyperoxaluria type 1 is responsible for pediatric kidney failure in 1 to 2% of cases. Novel therapies based on RNA interference are changing the natural history of the disease. However, for those who do progress to kidney failure, and for patients living in countries that cannot afford these expensive therapies, liver-kidney transplantation may remain the only efficient therapy.

The aim of the study was to evaluate the outcome of patients with primary hyperoxaluria type 1 who received simultaneous or sequential liver-kidney transplantation. We retrospectively evaluated 10 patients, five of whom received a simultaneous transplantation, and five underwent sequential transplantation, with a median postponement of the kidney transplantation of 8 months (range 4-20). Among the patients, 5 were from medium-low income countries.

Median follow up was 3.2 years (range 1.6-11). Median estimated glomerular filtration rate at 6 and 12 months was 81.2 (range: 45.7-108.8) and 79.3 ml/min/1.73m² (range 54.7-112.1) in patients who underwent simultaneous transplantation, and 45.7 (range 34.5-86.7) and 38.3 ml/min/1.73m² (range 29.9-77.5) in those with sequential transplantation (p:NS). Biopsies performed at 6 and 12 months showed precipitation of calcium oxalate crystals in 7 patients, demonstrating the recurrence of deposition despite the delay between liver and kidney transplantation. No differences in kidney function or in post-transplant renal oxalate precipitation were observed between patients that underwent bilateral nephrectomy and those who did not. As of their most recent follow up, none of the patients has lost their kidney graft.

Our study shows that by adapting the transplant strategy to individual cases, patients with primary hyperoxaluria type 1 can be successfully treated.