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

Abstract

Introduction: 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.

Methods: 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.

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

Conclusion: 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.