Combined liver-kidney transplantation in primary hyperoxaluria type 1

Primary hyperoxaluria type 1 (PH1) is a rare inherited condition that causes excessive calcium oxalate buildup in the body. This leads to kidney damage and systemic oxalosis when kidney function drops below 40-20 mL/min per 1.73 m². PH1 results from a defect in the alanine:glyoxylate aminotransferase (AGT) enzyme, which is normally located in liver peroxisomes. Diagnosis involves measuring urinary oxalate and glycollate, plasma oxalate levels, and AGT activity in liver biopsies. Traditional treatments like pyridoxine and dialysis have limited success. Isolated kidney transplants often fail due to disease recurrence. Liver function is key to preventing glyoxylate toxicity, but liver transplants alone are typically reserved for early-stage patients. Current evidence suggests that combined liver-kidney transplants may offer better outcomes than kidney transplants alone.

This review aims to evaluate the effectiveness of combined liver-kidney transplantation in managing PH1. The study focuses on how this dual approach addresses both the metabolic defect and organ damage caused by the disease. PH1 leads to progressive kidney failure and systemic oxalosis, so treating both organs may improve survival and quality of life. The authors compare outcomes of combined transplants with those of isolated liver or kidney transplants. They also examine the role of liver transplants in correcting the underlying metabolic issue. The goal is to determine whether combined transplants provide better long-term benefits than single-organ approaches. The study draws on European clinical experience to assess survival rates and graft function. The findings may guide treatment decisions for PH1 patients at different disease stages.

The authors conducted a literature review of PH1 treatment strategies, focusing on liver and kidney transplants. They analyzed data from European clinical experiences and patient outcomes. Diagnostic methods like urinary oxalate testing and AGT measurement in liver biopsies were discussed. The review included conservative treatments such as pyridoxine and hemodialysis. Isolated kidney transplants were evaluated for recurrence rates and graft survival. Liver transplants were examined for their role in correcting AGT deficiency. Combined liver-kidney transplants were compared in terms of patient and graft survival. The study also considered the impact of early transplantation on systemic oxalosis progression.

Combined liver-kidney transplants in PH1 patients showed an approximate 80% patient survival rate at 5 years and 70% at 10 years. Renal function in survivors remained stable, with glomerular filtration rates between 40 and 60 mL/min per 1.73 m² after 5 to 10 years. Isolated kidney transplants had a 100% recurrence rate and low graft survival of 15%-25% in Europe. Liver transplants alone were limited to early-stage patients and showed limited effectiveness in advanced cases. Combined transplants reversed systemic storage disease in tissues like bone and heart. Early transplantation improved outcomes by reducing oxalate accumulation. Liver transplants corrected the metabolic defect by restoring AGT activity. These findings suggest that combined transplants offer better long-term benefits than single-organ approaches.

The authors suggest that combined liver-kidney transplants provide better outcomes for PH1 patients than isolated kidney transplants. They propose that liver transplants correct the metabolic defect by restoring AGT activity in its normal location. The review indicates that combined transplants improve patient survival and graft function over time. Early transplantation appears to limit systemic oxalosis and improve quality of life. Liver transplants alone may reverse systemic storage disease in tissues like bone and vessels. The authors suggest that combined transplants are a conventional treatment for most PH1 patients. They propose that liver transplants function as a form of gene therapy by replacing the defective enzyme. The findings suggest that combined transplants should be considered for most PH1 patients.