RIS ID
39097
Abstract
Of the DNA-derived biomarkers of oxidative stress, urinary 8-oxo-7,8-dihydro-2′-deoxyguanosine (8-oxodG) is the most frequently measured. However, there is significant discrepancy between chromatographic and immunoassay approaches, and intratechnique agreement among all available chromatography-based assays and ELISAs is yet to be established. This is a significant obstacle to their use in large molecular epidemiological studies. To evaluate the accuracy of intra/intertechnique and interlaboratory measurements, samples of phosphate buffered saline and urine, spiked with different concentrations of 8-oxoG, together with a series of urine samples from healthy individuals were distributed to ESCULA members. All laboratories received identical samples, including 2 negative controls that contained no added 8-oxodG. Data were returned from 17 laboratories, representing 20 methods, broadly classified as mass spectrometric (MS), electrochemical detection (EC), or enzyme-linked immunosorbant assay (ELISA). Overall, there was good within-technique agreement, with the majority of laboratories' results lying within 1 SD of their consensus mean. However, ELISA showed more within-technique variation than did the chromatographic techniques and, for the urine samples, reported higher values. Bland-Altman plots revealed good agreement between MS and EC methods but concentration-dependent deviation for ELISA. All methods ranked urine samples according to concentration similarly. Creatinine levels are routinely used as a correction factor for urine concentration, and therefore we also conducted an interlaboratory comparison of methods for urinary creatinine determination, in which the vast majority of values lay within 1 SD of the consensus value, irrespective of the analysis procedure. This study reveals greater consensus than previously expected, although concern remains over ELISA. © FASEB.
Publication Details
Evans, M., Olinski, R., Loft, S., cooke, M., Rossner, J., Sram, R., Henriksen, T., Poulsen, H., Weimann, A., Barbieri, A., Sabatini, L., Violante, F., Kino, S., Ochi, T., Sakai, K., Takeuchi, M., Kasai, H., Meerman, J., Gackowski, D., Rozalski, R., Siomek, A., Halliwell, B., Jenner, A. M., Wang, H., Cerda, C., Saez, G., Haghdoost, S., Svoboda, P., Hu, C., Chao, M., Peng, K., Shih, W., Wu, K., Orhan, H., Istanbullu, N., Mistry, V., Farmer, P., Sandhu, J., Singh, R., Cortez, C., Su, Y., Santella, R., Lambert, P. & Smith, R. (2010). Toward consensus in the analysis of urinary 8-oxo-7,8-dihydro-2′- deoxyguanosine as a noninvasive biomarker of oxidative stress. FASEB Journal, 24 (4), 1249-1260.