Abstract: SAT 077
A Comparison of Serum Total Testosterone (TT) Measurements By Various Methods, Employing Current Validated Techniques, and Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)...
Presenter: Hugo E Scaglia
A Comparison of Serum Total Testosterone (TT) Measurements By Various Methods, Employing Current Validated Techniques, and Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS). a Multicentric Study Possible Interferences Affecting Laboratories Variability in TT Measurementsview more
A Comparison of Serum Total Testosterone (TT) Measurements By Various Methods, Employing Current Validated Techniques, and Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS). a Multicentric Study Possible Interferences Affecting Laboratories Variability in TT Measurements
Hugo E Scaglia*1, Graciela Buccini2, Carlos Chichizola3, Miriam Elisa Colombani1, Nora Corazza4, Carlos Corthey5, Laura Guevel6, Gladys Iabañez7, Eduardo Lacoste8, Sergio Nossetto9, Roberto Piaggio10, Oscar Riesco11, Silvia Sandoz12, Javier Scaglia13, Ana Viola14, Daniel Wolfthal15 and Clara Cecilia Zylbersztein16
1IABE, La Plata, Argentina, 2Laboratorio Buccini, Argentina, 3Alkemy diagnostic, Argentina, 4Laboratorio Corazza, Argentina, 5Labortorio Lebym, Argentina, 6Laboratorio Dra Guevel, Argentina, 7Laboratorio Ibañez, Argentina, 8Laboratorio Dr. Lacoste, Argentina, 9Bioanalitica, Argentina, 10Indabi, Argentina, 11Laboratorio Riesco, Argentina, 12Laboratorio Nanni, Argentina, 13Hospital Italiano, Argentina, 14Laboratorio Viola, Argentina, 15Laboratorio 12 de octubre, Argentina, firstname.lastname@example.org, Argentina
In a previous study, by using standard routinely reagents for the determination of peripheral TT levels, we have demonstrated that two commercial kits (from Abbott and Roche Laboratories) validated respect to LC MSMS, met the requirements of acceptability at discretion of CDC. The aim of this study which was directed toward the standardization of results obtained throughout different biochemical laboratories. Aliquots from the same sera samples (obtained from 40 women) were prepared in duplicate and then assayed in 5 laboratories (Labs) with reagents from Abbott and in 6 Labs with those from Roche, by following two different approaches: 1) methodology usually used by each Lab itself, and 2) in each laboratory by using the same lot of kit, calibrators and control samples. As an external control, an aliquot of sample was sent to Quest for TT evaluation by LC MSMS. According to TT values obtained by LC MSMS, data from samples assayed were split into 2 groups: a) with normal TT values, and b) with high TT values. Statistical analyses of results (expressed in ng/ml) obtained by both methods were then compared with those obtained by LC MSMS.Regarding data obtained throughout study-approach 1), sample values included in group a) were: 0.27±0.06 when assayed by LC MSMS; 0.33±0.05, 0.36±0.05, 0.33±0.05, 0.33±0.05 and 0.35±0.04 when assayed with Abbot`s kit in 5 Labs, respectively; and 0.24±0.04, 0.26±0.05, 0.29±0.05, 0.28±0.06, 0.25±0.06 and 0.30±0.09 when assayed with Roche’s kit in 6 Labs, respectively. Sample values included in group b) were: 0.86±0.34 when assayed by LC MSMS; 0.87±0.37, 1.03±0.41, 0.99±0.40, 0.95±0.38 and 1.01±0.42 when assayed with Abbot`s kit in 5 Labs, respectively; and 0.78±0.32, 0.85±0.38, 0.88±0.38, 0.91±0.37, 0.84±0.36 and 0.82±0.38 when assayed with Roche’s kit in 6 Labs, respectively. Regarding results from study-approach 1), all data derived from Abbott’s kit assay resulted significantly (p<0.5 by ANOVA and Pearson’s correlation coefficient) different from those obtained by LC-MSMS. BIAS analysis showed a positive tendency because all data (regardless the kits employed) resulted higher than values obtained by LC MSMS. Conversely, the analyses indicated a high correlation of values obtained with Roche’s kit (in 4 from 6 Labs), results matched with those obtained by the reference method (p> 0.05) and showed a BIAS result within the confidentiality CDC limits (± 6.5%). Regarding the study-approach 1), when analyzed as a whole, difference -5 to +10.6 % difference was noticed with Abbott reagents, and -11.0 to +10.6 % with Roche reagents. On the other hand, in the study-approach 2), differences for the same samples were -1.6 to 5.5 % and -8.9 to 10.6 % for Abbott and Roche reagents, respectively. In conclusion, laboratory variability in TT quantifications seems to be independent on kits reagents, including calibrators and control sample.
Nothing to Disclose: HES, GB, CC, MEC, NC, CC, LG, GI, EL, SN, RP, OR, SS, JS, AV, DW, CCZ
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