Interlaboratory comparison of methodologies for the measurement of urinary 8-oxo-7,8-dihydro-2′-deoxyguanosine

Abstract

Urinary 8-oxo-7,8-dihydro-2′-deoxyguanosine (8-oxodGuo) is widely used as a marker of oxidative stress. Here we report the comparison of two, distinct chromatographic assays with an enzyme-linked immunosorbent assay (ELISA). The chromatographic assays displayed good agreement (r =:0.89, p < 0.0001), whereas there was markedly worse, albeit still significant, agreement with the ELISA (high-pressure liquid chromatography followed by gas chromatography (HPLC-GC/MS), r = 0.43; HPLC with electrochemical detection (HPLC-EC), r = 0.56; p < 0.0001). Mean values differed significantly between the chromatographic assays and the ELISA (HPLC-GC/MS 3.86, HPLC-EC 4.20, ELISA 18.70 ng mg⁻¹ creatinine; p < 0.0001). While it is reassuring to note good agreement between chromatographic assays, this study reveals significant short-comings in the ELISA, which brings into question its continued use in its present form.

Keywords::

• Oxidative stress
• 8-oxodGuo
• ELISA
• HPLC
• GC/MS
• urine
• biomarkers
• molecular epidemiology

Acknowledgements

This work was partly supported by ECNIS. M.S.C., M.D.E., R.R., D.G., A.S., M.F. and R.O. are partners of ECNIS (Environmental Cancer Risk, Nutrition and Individual Susceptibility), a network of excellence operating within the European Union 6th Framework Program, Priority 5: ‘Food Quality and Safety’ (Contract No. 513943). The research related to the analysis of 8-oxodGuo using the HPLC-EC method was supported by the Japan Society for the Promotion of Science.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.