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.
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.