Plasma oxalate: comparison of methodologies

Felicity Stokes, Cecile Acquaviva-Bourdain, Bernd Hoppe, John C. Lieske, Elisabeth Lindner, Greg Toulson, Frédéric M. Vaz, Gill Rumsby

Research output: Contribution to journalArticlepeer-review

2 Scopus citations


Measurement of oxalate in the blood is essential for monitoring primary hyperoxaluria patients with progressive renal impairment and on dialysis prior to transplantation. As no external quality assurance scheme is available for this analyte, we conducted a sample exchange scheme between six laboratories specifically involved with the investigation of primary hyperoxaluria to compare results. The methodologies compared were gas chromatography/mass spectrometry (GCMS), ion chromatography with mass spectrometry (ICMS), and enzymatic methods using oxalate oxidase and spectrophotometry. Although individual laboratories performed well in terms of reproducibility and linearity, there was poor agreement (absolute values) between centres as illustrated by a longer-term comparison of patient results from two of the participating laboratories. This situation was only partly related to differences in calibration and mainly reflected the lower recoveries seen with the ultrafiltration of samples. These findings lead us to conclude that longitudinal monitoring of primary hyperoxaluria patients with deteriorating kidney function should be performed by a single consistent laboratory and the methodology used should always be defined. In addition, plasma oxalate concentrations reported in registry studies and those associated with the risk of systemic oxalosis in published studies need to be interpreted in light of the methodology used. A reference method and external quality assurance scheme for plasma oxalate analysis would be beneficial.

Original languageEnglish (US)
Pages (from-to)473-480
Number of pages8
Issue number6
StatePublished - Dec 2020


  • Method comparison
  • Plasma oxalate
  • Primary hyperoxaluria
  • Ultrafiltration

ASJC Scopus subject areas

  • Urology


Dive into the research topics of 'Plasma oxalate: comparison of methodologies'. Together they form a unique fingerprint.

Cite this