Monge-Argilés Jose Antonio, Muñoz-Ruiz Carlos, Sánchez-Payá José, Gasparini Berenguer Ruth, Blanco Cantó Maria Empar, Leiva-Santana Carlos
Department of Neurology, University General Hospital of Alicante, Avenida Pintor Baeza 12, 8 C, 03010 Alicante, Spain.
Laboratory of Immunology, University General Hospital of Alicante, Avenida Pintor Baeza 12, 8 C, 03010 Alicante, Spain.
Biomed Res Int. 2014;2014:765130. doi: 10.1155/2014/765130. Epub 2014 May 29.
Cerebrospinal fluid (CSF) biomarkers of Alzheimer's disease (AD) are currently being assessed with two different assays. Our objective was to study if there is a correlation between values obtained by both techniques, to compare their validity and search for conversion factor between values obtained for every protein. We compared the performances of two commonly used platforms, an enzyme-linked immunosorbent assay (ELISA) and a multiplex (xMAP) technology for measurement of CSF Aβ 1-42, total tau (T-tau), and phosphorylated tau 181 (P-tau 181p) proteins, in 30 AD patients and 28 control subjects. The relations between the variables of both techniques were evaluated using the Spearman p correlation coefficient (α = 0.05). Receiver operating characteristic and area under the curve (AUC) analyses were calculated for the variables of both techniques. The two assays platforms yielded different absolute values for the various analytes, always higher in ELISA. We found some correction factor between values: 2,1- to 3-fold for Aβ 1-42; 4,1- to 4,6-fold for T-tau; and 1,4- to 1,6-fold for P-tau 181p. In addition, those values were highly correlated (Aβ 1-42: r = 0.70, P < 0.01; T-tau: r = 0.90, P < 0.01; P-tau 181p: r = 0.85, P < 0.01) and the AUC for the variables showed very similar values. In conclusion, the results obtained with ELISA and xMAP platforms were highly correlated and its validity is very similar. Differences in absolute values point to the need for a clear description of the technique used. Moreover, we found some conversion factor between values of every protein that may be useful for transformation between both techniques.
目前正在通过两种不同的检测方法评估阿尔茨海默病（AD）的脑脊液（CSF）生物标志物。我们的目的是研究两种技术所获数值之间是否存在相关性，比较它们的有效性，并寻找每种蛋白质所获数值之间的转换因子。我们比较了两种常用平台的性能，即酶联免疫吸附测定（ELISA）和用于测量脑脊液淀粉样β蛋白1-42（Aβ 1-42）、总tau蛋白（T-tau）和磷酸化tau蛋白181（P-tau 181p）的多重（xMAP）技术，研究对象为30例AD患者和28名对照受试者。使用Spearman相关系数（α = 0.05）评估两种技术变量之间的关系。计算两种技术变量的受试者工作特征曲线和曲线下面积（AUC）分析。两种检测平台对各种分析物得出的绝对值不同，ELISA得出的值总是更高。我们发现了数值之间的一些校正因子：Aβ 1-42为2.1至3倍；T-tau为4.1至4.6倍；P-tau 181p为1.4至1.6倍。此外，这些数值高度相关（Aβ 1-42：r = 0.70，P < 0.01；T-tau：r = 0.90，P < 0.01；P-tau 181p：r = 0.85，P < 0.01），变量的AUC显示出非常相似的值。总之，ELISA和xMAP平台获得的结果高度相关，其有效性非常相似。绝对值的差异表明需要清晰描述所使用的技术。此外，我们发现了每种蛋白质数值之间的一些转换因子，这可能有助于两种技术之间的转换。
