Clearance and removal of oxalate in children on intensified dialysis for primary hyperoxaluria type 1

Abstract

Patients with end-stage renal failure owing to primary hyperoxaluria type 1 (PH1) receive dialysis while waiting for transplantation. So far, dialysis has not been shown to overcome the problem of ongoing oxalate production and deposition at extrarenal sites. We report on six children with PH1 who had to be dialyzed for a median period of 2.5 years while awaiting liver transplantation. Aiming at preventing oxalate tissue accretion, oxalate mass transfer was studied and dialysis intensified accordingly. Mean plasma oxalate concentration was between 51 and 137 micromol/l. In three of the six patients with a urinary output between 630 and 3140 ml, urinary removal of oxalate was between 5.6 and 12.4 mmol/week/1.73 m2. Hemodialysis (HD) in five of the six patients demonstrated a mean oxalate dialysance between 158 and 444 l/week/1.73 m2. Peritoneal dialysis (PD) in two of the six patients showed mean oxalate clearances of 66 and 103 l/week/1.73 m2. One patient received HD and PD. By adding all modes of elimination, a mean total oxalate mass between 10.1 and 24.1 mmol/week/1.73 m2 was removed. Dialysis is still necessary as a temporary therapy for a number of patients with PH1. Dialysis should be instituted pre-emptively and maximally exploited by intensified HD/PD treatment protocols, without, however, cutting back urinary output.

Characteristics and Outcomes of Children with Primary Oxalosis Requiring Renal Replacement Therapy

“…combined hemodialysis and peritoneal dialysis (10,11), consideration of timing of liver-kidney transplantation (17), and specific perioperative management (35) may have contributed to better management of oxalosis. Although we found no association of dialysis duration on patient or kidney graft survival, unlike in other studies (7,14), the increasing time spent on dialysis by PH children may jeopardize some of the progress seen in this study.…”

“…In theory, dialysis is ineffective for patients who have reached ESRD because it cannot overcome the continuous production of oxalate by the liver (10). However, in clinical practice, dialysis is required as a temporary therapy for a number of patients.…”

Novel findings in patients with primary hyperoxaluria type III and implications for advanced molecular testing strategies

“…4,5 With advanced renal insufficiency and failure to excrete the metabolic end product oxalic acid, the disease turns into a lethal multisystemic condition making renal replacement therapy and subsequent liver-kidney transplantation mandatory. [6][7][8][9][10] Type II PH (PHII, MIM# 260000; gene GRHPR, MIM# 604296) is a result of deficient glyoxylate reductase/hydroxypyruvate reductase (GRHPR) enzyme activity. 11 In general, PHII shows a milder course with the absence of infantile oxalosis and ESRD occurring in about 20% of patients.…”

Primary and secondary hyperoxaluria: Understanding the enigma

“…The weekly removal of oxalate by hemodialysis or peritoneal dialysis has been calculated to be 610 mmol/1.73 m 2 [92,93] which leaves patients in a positive oxalate balance and at high risk for systemic deposition. Illies et al [94] studied 6 patients with PH1 who were on dialysis and awaiting liver transplant. Based on their observations, they made recommendations for improvement of the dialysis prescription.…”

“…The timing of HD and PD should be coordinated as PD may be more efficient in removing oxalate in the later phases of the interdialytic period when rebound is much higher than in the earlier interdialytic phase. Efforts should be made to keep the oxalate level below 50 μmol/L [94] . The intensification of dialysis may pose a burden on the patient and family and it is important to keep this in mind while designing an individualized dialysis plan.…”