Merrigan Stephen D, Owen William E, Straseski Joely A
Clin Lab. 2015;61(3-4):283-8. doi: 10.7754/clin.lab.2014.140817.
Vitamin B12 (cobalamin) is a necessary cofactor in methionine and succinyl-CoA metabolism. Studies estimate the deficiency prevalence as high as 30% in the elderly population. Ten to thirty percent of circulating cobalamin is bound to transcobalamin (holotranscobalamin, holoTC) which can readily enter cells and is therefore considered the bioactive form. The objective of our study was to evaluate the analytical performance of a high-throughput, automated holoTC assay (ARCHITECT i2000(SR) Active-B12 (Holotranscobalamin)) and compare it to other available methods.
Manufacturer-specified limits of blank (LoB), detection (LoD), and quantitation (LoQ), imprecision, interference, and linearity were evaluated for the ARCHITECT HoloTC assay. Residual de-identified serum samples were used to compare the ARCHITECT HoloTC assay with the automated AxSYM Active-B12 (Holotranscobalamin) assay (Abbott Diagnostics) and the manual Active-B12 (Holotranscobalamin) Enzyme Immunoassay (EIA) (Axis-Shield Diagnostics, Dundee, Scotland, UK).
Manufacturer's claims of LoB, LoD, LoQ, imprecision, interference, and linearity to the highest point tested (113.4 pmol/L) were verified for the ARCHITECT HoloTC assay. Method comparison of the ARCHITECT HoloTC to the AxSYM HoloTC produced the following Deming regression statistics: (ARCHITECT(HoloTc)) = 0.941 (AxSYM(HoloTC)) + 1.2 pmol/L, S(y/x) = 6.4, r = 0.947 (n = 98). Comparison to the Active-B12 EIA produced: (ARCHITECT(HoloTC)) = 1.105 (EIA(Active-B12)) - 6.8 pmol/L, S(y/x) = 11.0, r = 0.950 (n = 221).
This assay performed acceptably for LoB, LoD, LoQ, imprecision, interference, linearity and method comparison to the predicate device (AxSYM). An additional comparison to a manual Active-B12 EIA method performed similarly, with minor exceptions. This study determined that the ARCHITECT HoloTC assay is suitable for routine clinical use, which provides a high-throughput alternative for automated testing of this emerging marker of cobalamin deficiency.
维生素B12（钴胺素）是蛋氨酸和琥珀酰辅酶A代谢中必需的辅因子。研究估计老年人群中维生素B12缺乏症的患病率高达30%。循环中的钴胺素10%至30%与转钴胺素（全转钴胺素，holoTC）结合，holoTC可轻易进入细胞，因此被认为是生物活性形式。我们研究的目的是评估一种高通量自动化全转钴胺素检测方法（ARCHITECT i2000(SR)活性B12（全转钴胺素））的分析性能，并将其与其他现有方法进行比较。
对ARCHITECT全转钴胺素检测方法的制造商规定的空白限（LoB）、检测限（LoD）、定量限（LoQ）、不精密度、干扰和线性进行评估。使用剩余的去识别血清样本，将ARCHITECT全转钴胺素检测方法与自动化AxSYM活性B12（全转钴胺素）检测方法（雅培诊断）和手动活性B12（全转钴胺素）酶免疫测定法（EIA）（Axis-Shield诊断，英国苏格兰邓迪）进行比较。
ARCHITECT全转钴胺素检测方法在LoB、LoD、LoQ、不精密度、干扰和线性方面，对于测试的最高点（113.4 pmol/L），制造商的声明得到了验证。ARCHITECT全转钴胺素检测方法与AxSYM全转钴胺素检测方法的方法比较产生了以下Deming回归统计结果：（ARCHITECT（全转钴胺素））=0.941（AxSYM（全转钴胺素））+1.2 pmol/L，S(y/x)=6.4，r=0.947（n=98）。与活性B12 EIA的比较结果为：（ARCHITECT（全转钴胺素））=1.105（EIA（活性B12））-6.8 pmol/L，S(y/x)=11.0，r=0.950（n=221）。
该检测方法在LoB、LoD、LoQ、不精密度、干扰、线性以及与对照设备（AxSYM）的方法比较方面表现良好。与手动活性B12 EIA方法的额外比较结果相似，仅有小的差异。本研究确定ARCHITECT全转钴胺素检测方法适用于常规临床应用，为这种新出现的钴胺素缺乏标志物的自动化检测提供了一种高通量替代方法。
