Department of Biochemistry, Hospital de la Santa Creu i Sant Pau, Biomedical Research Institute (IIB) Sant Pau, Barcelona, Spain.
Sant Pau Memory Unit, Department of Neurology, Hospital de la Santa Creu i Sant Pau, Biomedical Research Institute (IIB) Sant Pau, Barcelona, Spain.
Clin Chem Lab Med. 2022 Apr 12;60(7):1058-1063. doi: 10.1515/cclm-2022-0134. Print 2022 Jun 27.
Alzheimer's disease (AD) is considered the most common cause of dementia in older people. Cerebrospinal fluid (CSF) Aβ1-42, Aβ1-40, total Tau (t-Tau), and phospho Tau (p-Tau) are important biomarkers for the diagnosis, however, they are highly dependent on the pre-analytical conditions. Our aim was to investigate the potential influence of different storage conditions on the simultaneous quantification of these biomarkers in a fully-automated platform to accommodate easier pre-analytical conditions for laboratories.
CSF samples were obtained from 11 consecutive patients. Aβ1-42, Aβ1-40, p-Tau, and t-Tau were quantified using the LUMIPULSE G600II automated platform.
Temperature and storage days significantly influenced Aβ1-42 and Aβ1-40 with concentrations decreasing with days spent at 4 °C. The use of the Aβ1-42/Aβ1-40 ratio could partly compensate it. P-Tau and t-Tau were not affected by any of the tested storage conditions. For conditions involving storage at 4 °C, a correction factor of 1.081 can be applied. Diagnostic agreement was almost perfect in all conditions.
Cutoffs calculated in samples stored at -80 °C can be safely used in samples stored at -20 °C for 15-16 days or up to two days at RT and subsequent freezing at -80 °C. For samples stored at 4 °C, cutoffs would require applying a correction factor, allowing to work with the certainty of reaching the same clinical diagnosis.
阿尔茨海默病（AD）被认为是老年人痴呆症的最常见原因。脑脊液（CSF）中的 Aβ1-42、Aβ1-40、总 Tau（t-Tau）和磷酸化 Tau（p-Tau）是诊断的重要生物标志物，然而，它们高度依赖于分析前条件。我们的目的是研究不同储存条件对这些生物标志物在全自动平台上同时定量的潜在影响，以适应实验室更简单的分析前条件。
从 11 名连续患者中获得 CSF 样本。使用 LUMIPULSE G600II 自动化平台定量测定 Aβ1-42、Aβ1-40、p-Tau 和 t-Tau。
温度和储存天数对 Aβ1-42 和 Aβ1-40 有显著影响，浓度随 4°C 储存天数的增加而降低。使用 Aβ1-42/Aβ1-40 比值可以部分补偿。任何测试的储存条件都不会影响 p-Tau 和 t-Tau。对于涉及 4°C 储存的条件，可以应用 1.081 的校正因子。在所有条件下，诊断一致性几乎都是完美的。
在-80°C 储存的样本中计算的截止值可安全地用于在-20°C 储存 15-16 天或在 RT 下储存最多两天，随后在-80°C 下冷冻的样本中使用。对于在 4°C 下储存的样本，截止值需要应用校正因子，以确保达到相同的临床诊断。
