Newborn screening blood spot analysis in the UK: influence of spot size, punch location and haematocrit
Newborn screening blood spot analysis in the UK: influence of spot size, punch location and haematocrit
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DOI：
10.1177/0969141315593571
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发表时间：
2016-03-01
影响因子：
2.9
通讯作者：
Hall, S. K.
中科院分区：
文献类型：
--
作者：
Lawson, A. J.;Bernstone, L.;Hall, S. K.
目的：在干血斑分析中，穿孔位置和所应用的样品体积和红细胞压积的变化可以产生不同的分析物测量浓度。我们调查了这些影响的幅度在新生儿筛选在UK.Methods：肝素化血液加标促甲状腺激素（TSH），苯丙氨酸，酪氨酸，亮氨酸，蛋氨酸，辛酰肉毒碱（C8），和免疫反应性胰蛋白酶原（IRT）被点到滤纸上：（i）在一个恒定的红细胞压积为50%，在不同的体积，和（ii）在一系列的红细胞压积使用一个恒定的体积。Subpunks（3.2mm）的干血斑，然后analysed.Results：从50 μ L的血斑与50%红细胞压积，10 μ L的斑点可以有显着较低的测量浓度的所有分析物相比，减少了15%或更多的观察亮氨酸，蛋氨酸，苯丙氨酸和酪氨酸的中央打孔。在点的边缘打孔可以使测量浓度增加35%。较高的红细胞压积降低测得的TSH和C8，但增加氨基酸和IRT的15%相比，50%的红细胞压积。较低的红细胞压积有相反的效果，但只有较高的浓度的一些analyses.Conclusions：血斑大小，红细胞压积和打孔位置的差异，大大影响测量浓度的分析物在英国新生儿筛查计划，这可能会影响假阳性和阴性率。为了尽量减少分析偏倚，应尽可能控制或调整这些变量。
Objective: In dried blood spot analysis, punch location and variations in applied sample volume and haematocrit can produce different measured concentrations of analytes. We investigated the magnitude of these effects in newborn screening in the UK.Methods: Heparinized blood spiked with thyroid stimulating hormone (TSH), phenylalanine, tyrosine, leucine, methionine, octanoyl carnitine (C8), and immunoreactive trypsinogen (IRT) was spotted onto filter paper: (i) at a constant haematocrit of 50% at various volumes, and (ii) at a range of haematocrits using a constant volume. Subpunches (3.2mm) of the dried blood spots were then analysed.Results: Compared with a central punch from a 50 mu L blood spot with 50% haematocrit, 10 mu L spots can have significantly lower measured concentrations of all analytes, with decreases of 15% or more observed for leucine, methionine, phenylalanine, and tyrosine. Punching at the edge of a spot can increase measured concentrations up to 35%. Higher haematocrit decreased measured TSH and C8 yet increased amino acids and IRT by 15% compared with 50% haematocrit. Lower haematocrits had the opposite effect, but only with higher concentrations of some analytes.Conclusions: Differences in blood spot size, haematocrit and punch location substantially affect measured concentrations for analytes used in the UK newborn screening programme, and this could affect false positive and negative rates. To minimize analytical bias, these variables should be controlled or adjusted for where possible.