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Mar del Plata, Argentina

Scaglia H.E.,Hormone Determination Laboratory | Buccini G.,Hormone Determination Laboratory | Chichizola C.,Hormone Determination Laboratory | Colombani M.E.,Hormone Determination Laboratory | And 13 more authors.
Revista Argentina de Endocrinologia y Metabolismo | Year: 2015

Objective: To compare normal and hirsute women Testosterone (T) measurements performed at different laboratories by the same or different methods, and the gold standard method LC-MS/MS (Quest Diagnostics, USA). Design: Prospective study. Setting: Hormone Determination Laboratory, Hospital Italiano, La Plata, and each participating laboratory's private practice. Patient(s): Blood samples were obtained from 23 individuals sorted into two groups, namely, normal women, n: 11(NW) and hirsute women, n: 12 (HW). Interventions(s): None. Main Outcome Measure(s): To evaluate whether serum T measurements obtained from each serum by the methods currently employed in our country, some of whose kits exhibit changes in previous presentations, some LC-MS/MS-validated and other non-validated ones are significantly different from those obtained by LC-MS/MS. Result(s): None of the 11 NW showed high T values by LC-MS/MS. Two out of the 12 hirsute patients showed normal T values (LC-MS/MS). Methods and number of participating labs-shown between brackets were: in NW, 1st generation Architect (1), 2nd generation Architect (1); Immulite (1) Cobas (4); Access (1); Centaur (2); Immunotech-RIA (1); and, in HW, 2nd generation Architect (3); Immulite (3); Cobas (4); Access (1); Centaur (2); Immunotech-RIA (1). No false positives resulted from the assays performed. No lab yielded false positive results in the NW group. No false positives were reported from the 10 hirsute women with increased T values by LC-MS/MS. False positives, though, resulted from two female hirsute patients with normal T values studied by four of the methods. Statistically, the serum T measurements obtained were significantly different by Centaur in NW and, in HW, by Immulite and Centaur as compared to LC-MS/MS. In the Bland-Altman plot, Centaur and Cobas showed over 5 % of measurements outside the limits of agreement in the HW group. Assessment by p-Spearman resulted in divergences with LC-MS/MS for all methods in NW, whereas in the HW group there were none. When estimating sampling bias for each laboratory taking LC-MS/MS as the reference method and adopting a ± 6.4 % mean bias acceptability criterion for each method compared to LC-MS/MS, two of the techniques reviewed, 2nd generation Architect and Cobas, met the validation requirement satisfactorily. However, one lab out of three using 2nd generation Architect failed to meet the validation requirement, while two out of four labs using Cobas also failed to meet the requirement. This demonstrates the great variability among methods, even when labs are employing the same technique. Conclusion: From the clinical point of view, the methods currently used in our local environment yielded no false positives or false negatives and therefore did not misdiagnose hyperandrogenism. Still, Immulite, Centaur, RIA and Access did present false positives in two of the T-normal hirsute women. The relation of serum T measurements obtained by each method to measurements obtained by LC-MS/MS reveals that the dispersion of the results was larger with values under 0.3 ng/ml, quite close to the detection limit of the various techniques. Rev Argent Endocrinol Metab 52:137-152, 2015. Copyright ® 2015 por la Sociedad Argentina de Endocrinología y Metabolismo. Source


Scaglia H.E.,Hormone Determination Laboratory | Aquilano D.R.,Hormone Determination Laboratory | Buccini G.,Hormone Determination Laboratory | Chichizola C.,Hormone Determination Laboratory | And 16 more authors.
Revista Argentina de Endocrinologia y Metabolismo | Year: 2012

Objective: To compare T results in normal and hirsute women, obtained by different laboratories employing the same or different methods, including an in-home RIA, and the gold standard method LC-MS/MS. In addition, T results were referred to a curve obtained by 6 different pools that had been prepared on the basis of LC-MS/MS results. Design: Prospective study Setting: Hormone Determination Laboratory, Hospital Italiano, La Plata, and private practice of each participant laboratory. Patient(s): Blood samples were obtained from 78 individuals sorted into 3 groups, namely, normal men (n:39), normal women (n:24) and hirsute women (n:15) Interventions(s): None Main Outcome Measure(s): To evaluate if the results obtained in each lab for each serum sample by the methods currently employed in our country are significantly different from those obtained by LC-MS/MS (Gold standard) Result(s): One out of the 24 NW showed high T values by LC-MS/MS. In each lab, except in 1 (Architect) T results of this serum sample were normal. Two out of the 15 hirsute patients showed normal T values (LC-MS/MS). Method and number of labs -shown between brackets- and percentages of normal T results (false negatives) are described for each method as follows: Chemiluminescence: Axsym - Abbott (Axn) - (3) 85, Architect - Abbott - (Arch); (2) 70; Immulite - Siemmens - (IMM); (2) 42; Electrochemiluminescence - Elecsys - Roche- ((EQL); (4) 52; Fluorescent enzymatic - Vidas - Bio-Merieux - (Vidas) (1) 69; Manual coated tube radioimmunoassay (RIA): RIA - Siemmens Coat-a-Count (RIA S); (3) 64; RIA - DSL Inc (RIA DSL); (1) 31; RIA - DIASource - (DiaS); (1) 31; and in-Home RIA (in-H) (1) 12. Statistically significant differences were obtained between different methods and against LC MS/MS. In-H method is the one that comes closest to 1 on the Weighted Deming regression and closest to zero on the SD intercept, (standard deviation of the constant in the straight line equation) indicating that the values match those obtained by LC-MS/MS. The values recorded by the various methods employed showed no significant modifications when plotted against a secondary standard curve. Conclusion(s): This indicates that the techniques in current use in our area underestimate hyperandrogenemia in these patients. Discrepancies are not due to the various calibration curves proposed in the corresponding commercial kits. The fact that the In-H technique affords finer results while employing a larger serum volume suggests that the disparities among the various commercial methods result from their limited sensitivity to the sample volumes they process. Copyright © 2012 por la Sociedad Argentina de Endocrinología y Metabolismo. Source

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