ESPN 53rd Annual Meeting

ESPN 2021


 
Plasma oxalate values in patients with end-stage kidney disease
ELISABETH METRY 1 SANDER GARRELFS 1 JOOST BIJLSMA 2 AEGIDA NERADOVA 2 FRED VAZ 3 MICHIEL OOSTERVELD 1 JAAP GROOTHOFF 1

1- DEPARTMENT OF PEDIATRIC NEPHROLOGY, EMMA CHILDRENS HOSPITAL, AMSTERDAM UMC, UNIVERSITY OF AMSTERDAM, AMSTERDAM, THE NETHERLANDS
2- DEPARTMENT OF NEPHROLOGY, AMSTERDAM UMC, UNIVERSITY OF AMSTERDAM, AMSTERDAM, THE NETHERLANDS
3- DEPARTMENT OF CLINICAL CHEMISTRY, AMSTERDAM UMC, UNIVERSITY OF AMSTERDAM, AMSTERDAM, THE NETHERLANDS
 
Introduction:

 

Patients with end-stage kidney disease (ESKD) are known to have higher plasma concentrations of metabolic waste products than healthy individuals. Patients with Primary Hyperoxaluria (PH), a rare congenital cause of ESKD, suffer from hepatic overproduction of the metabolic end product oxalate. Plasma oxalate (POx) levels are determined in the diagnostic and therapeutic work-up for PH. Remarkably, correct interpretation of these values is hampered by the absence of knowledge concerning POx levels in patients with ESKD due to common causes.

Material and methods:

 

In this observational study, we obtained POx values in patients with ESKD due to another cause than PH, to establish reference values in this patient group. We collected blood samples from 118 patients with eGFR < 15 mL/min/1.73 m2 who required maintenance hemodialysis or peritoneal dialysis at the Amsterdam UMC. In addition, we collected 15 blood samples from adults with chronic kidney disease (CKD) stage 4 and 5 who received no renal replacement therapy.

Results:

 

 

While there was a wide variation in patients with ESKD, the median POx level was 50 umol/L and lowest values were twice the upper reference limit that applies to healthy individuals (6.7 umol/L). Median POx level was 10.4 umol/L in patients with CKD stage 4 and 5 who received no renal replacement therapy.  

Conclusions:

 

This study shows that POx levels of 50 umol/L are not necessarily suggestive for PH which contradicts the current literature. This study could lead to a paradigm shift in the diagnostic and therapeutic work-up for patients with ESKD.