MO436PLASMA OXALATE VALUES IN PATIENTS WITH END-STAGE KIDNEY DISEASE

Abstract

Abstract Background and Aims 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. Method 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 120 adults with eGFR < 15 mL/min/1.73 m2 who required maintenance hemodialysis or peritoneal dialysis at the Amsterdam UMC. Results While there was a wide variation in POx levels in patients with ESKD, the median was 50 umol/L and lowest values were twice the upper reference limit that applies to healthy individuals (6.7 umol/L). Conclusion 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.