Hidden in CAKUT: Post-Transplant Diagnosis of Primary Hyperoxaluria Type 1 and Rescue Management Using Lumasiran

Primary hyperoxaluria type 1 (PH1) is a very rare inherited metabolic disorder characterized by excessive oxalate production due to mutation variants in the alanine-glyoxylate aminotransferase gene (AGXT). Approximately 4% of PH1 cases are diagnosed after kidney transplantation. Most post-transplant recurrences of PH1 are associated with poor graft outcomes. Lumasiran, a novel RNA interference (RNAi) therapeutic for PH1, was recently discovered with promising results.

This report describes a pediatric case of PH1 diagnosed post-kidney transplantation with graft dysfunction who was treated with extensive hemodialysis and lumasiran as rescue therapy.

Patient was able to stop hemodialysis with the improvement of her kidney function and plasma oxalate after the fourth dose of lumasiran.

This case underscores the importance of maintaining a high index of suspicion for PH1 in patients with congenital anomalies of the kidney and urinary tract (CAKUT) or unexplained end-stage kidney disease (ESKD) cases, even post-transplantation. It also demonstrates the potential efficacy of lumasiran in managing PH1 post-transplantation when combined with intensive hemodialysis and supportive care. However, more studies with prolonged follow-up periods are necessary to establish the long-term efficacy and safety of lumasiran in the treatment of PH1 without the requirement for liver transplantation.