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.
Toward consensus in the analysis of urinary 8-oxo-7,8-dihydro-2′- deoxyguanosine as a noninvasive biomarker of oxidative stress / Evans M.D.; Olinski R.; Loft S.; Cooke M.S.; Rossner Jr. P.; Sram R.; Henriksen T.; Poulsen H.E.; Weimann A.; Barbieri A.; Sabatini L.; Violante F.; Kino S.; Ochi T.; Sakai K.; Takeuchi M.; Kasai H.; Meerman J.H.N.; Gackowski D.; Rozalski R.; Siomek A.; Halliwell B.; Jenner A.M.; Wang H.; Cerda C.; Saez G.; Haghdoost S.; Svoboda P.; Hu C.-W.; Chao M.-R.; Peng K.-Y.; Shih W.-C.; Wu K.-Y.; Orhan H.; Istanbullu N.S.; Mistry V.; Farmer P.B.; Sandhu J.; Singh R.; Cortez C.; Su Y.; Santella R.M.; Lambert P.; Smith R.. - In: THE FASEB JOURNAL. - ISSN 0892-6638. - ELETTRONICO. - 24:4(2010), pp. 1249-1260. [10.1096/fj.09-147124]
Toward consensus in the analysis of urinary 8-oxo-7,8-dihydro-2′- deoxyguanosine as a noninvasive biomarker of oxidative stress
Sabatini L.;Violante F.;Su Y.;Smith R.
2010
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.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
