Cleveland Clinic, Department of Clinical Pathology, Cleveland, OH 44195, United States.
J Steroid Biochem Mol Biol. 2013 Jul;136:139-45. doi: 10.1016/j.jsbmb.2012.11.005. Epub 2012 Nov 29.
BACKGROUND/METHODS: A total of 95 human serum specimens, and a 12 specimen precision panel, were measured by 2 automated immunoassays (investigation use only DiaSorin LIAISON(®) 25 OH Vitamin D TOTAL Assay [LSN], and Siemens ADVIA Centaur(®) Vitamin D Total (VitD) assay [Centaur]) and the results compared against LC-MS/MS [LCMS] used as the reference method (Esoterix Inc.). For functional sensitivity and precision, 12 serum specimens [range 1.2-148ng/mL] were run in six replicates [N=30] or four replicates [N=20], respectively, for 5 consecutive days.
Passing-Bablok fit and Difference plot analysis [N=92] showed that although both immunoassays had comparable correlation coefficient [r] values to LCMS (0.936 and 0.933), the LSN assay results were statistically equivalent to those given by LCMS (slope 0.93, intercept -2.5), whereas the results of the Centaur assay showed overall significant assay bias compared to LCMS (slope 1.30, intercept -15.8) and this bias was more significant for doses <30ng/mL by LCMS [bias -30.4%; 95% limits of agreement -72.4% to 11.7%]. For specificity, based on 25-OHD2 and 25-OHD3 levels assessed by LCMS, we divided the specimens into 2 groups, one with detectable 25-OHD2 [Group 1, N=41] and the other with no detectible 25OHD2 [Group 2, N=51]. The 2 groups showed comparable correlation coefficient [r] values between the methods, but showed significant differences in slope: Centaur [1.48 with group 1 and 1.18 with group 2] compared to LSN [0.91 with Group 1 and 0.96 with Group 2]. LSN demonstrated better precision [total CV range 5.5-10.0%] compared to Centaur [total CV range 11.0-16.3%]. Functional sensitivity was calculated per EP-17A: 2.15ng/mL by LSN and 4.57ng/mL by Centaur.
Though there was good overall correlation, substantial bias was present in Centaur. Although LSN had a slope and intercept that was not significantly different than LCMS, Centaur had a significantly higher slope in specimens containing measurable 25-OHD2 levels, a large negative intercept and a significant negative dose bias for doses <30ng/mL by LCMS, suggesting the Centaur assay would report a higher frequency of patients with apparent vitamin D insufficiency/deficiency at the low end and apparent vitamin D toxicity at the high end compared against LCMS. This article is part of a Special Issue entitled 'Vitamin D Workshop'.
背景/方法：共有 95 份人血清标本和 12 份标本精密度面板，使用 2 种自动化免疫分析法（仅供研究使用的 DiaSorin LIAISON(®)25 OH 维生素 D 总量检测试剂盒 [LSN]和西门子 ADVIA Centaur(®)维生素 D 总量检测试剂盒 [Centaur]）进行检测，并与作为参考方法的 LC-MS/MS[LCMS]进行比较（Esoterix Inc.）。为了进行功能灵敏度和精密度检测，将 12 份血清标本[范围为 1.2-148ng/mL]分别以 6 个重复[N=30]或 4 个重复[N=20]进行运行，连续 5 天进行 5 次检测。
Passing-Bablok 拟合和差值图分析[N=92]显示，虽然两种免疫分析法与 LCMS 的相关性系数[r]值相当（0.936 和 0.933），但 LSN 检测结果与 LCMS 相比具有统计学等效性（斜率 0.93，截距-2.5），而 Centaur 检测结果与 LCMS 相比显示出总体显著的检测偏差（斜率 1.30，截距-15.8），并且对于 LCMS 检测值<30ng/mL 的剂量，这种偏差更为显著[偏差-30.4%；95%置信区间为-72.4%至 11.7%]。对于特异性，根据 LCMS 评估的 25-OHD2 和 25-OHD3 水平，我们将标本分为两组，一组具有可检测的 25-OHD2[组 1，N=41]，另一组无可检测的 25-OHD2[组 2，N=51]。两组方法之间的相关性系数[r]值相当，但斜率存在显著差异：Centaur[1.48 与组 1和 1.18 与组 2]与 LSN[0.91 与组 1和 0.96 与组 2]相比。LSN 显示出比 Centaur 更好的精密度[总 CV 范围为 5.5-10.0%]。功能灵敏度根据 EP-17A 计算：LSN 为 2.15ng/mL，Centaur 为 4.57ng/mL。
尽管总体相关性良好，但 Centaur 存在明显的偏差。虽然 LSN 的斜率和截距与 LCMS 无显著差异，但 Centaur 在含有可测量 25-OHD2 水平的标本中具有更高的斜率、更大的负截距和显著的负剂量偏差，对于 LCMS 检测值<30ng/mL 的剂量，这表明 Centaur 检测法在低端会报告更高比例的维生素 D 不足/缺乏的患者，在高端会报告更高比例的维生素 D 毒性患者，与 LCMS 相比。本文是题为“维生素 D 研讨会”的特刊的一部分。
