Department of Laboratory Medicine, Toho University Graduate School of Medicine, Tokyo, Japan.
Department of Clinical Laboratory, Toho University Omori Medical Center, Tokyo, Japan.
J Clin Lab Anal. 2022 Sep;36(9):e24608. doi: 10.1002/jcla.24608. Epub 2022 Jul 19.
For the lack of standardized activated partial thromboplastin time (APTT), it has been pointed out that there are differences in values among several reagents. Recently, we have performed a parallel measurement on two reagents, Thrombocheck APTT-SLA and Coagpia APTT-n, and resulted with some dissociated samples. The purpose of this study is to clarify the possible factors related to ΔAPTT, the difference in measured values between the two reagents.
In order to clarify the factors related to ΔAPTT, multiple regression analysis was performed on 8324 samples, using clinical laboratory data of all test items requested simultaneously with APTT. To confirm the items extracted from the multiple regression analysis, the target substance was spiked to pooled plasma and measured with two APTT reagents. Additionally, by spiking phospholipids, the effect on APTT measurement system was assessed.
Multiple regression analysis detected albumin-globulin ratio (AGR), C-reactive protein (CRP), hematocrit, and prothrombin time as factors related to ΔAPTT (p < 0.001). Results revealed no significant differences when albumin was added to change the AGR. Whereas with the addition of CRP, prolongation of APTT was observed in Coagpia APTT-n compared to Thrombocheck APTT-SLA (p < 0.001). This prolongation was canceled by the addition of phospholipids, suggesting the interaction of CRP with phospholipids leads to the pseudo-prolongation.
It is considered that the pseudo-prolongation of APTT is triggered by the interaction of CRP on the phospholipid in Coagpia APTT-n, which contributed to the APTT dissociation.
由于缺乏标准化的活化部分凝血活酶时间（APTT），已经指出几种试剂之间存在值的差异。最近，我们对两种试剂，Thrombocheck APTT-SLA 和 Coagpia APTT-n 进行了平行测量，并得到了一些分离的样本。本研究的目的是阐明与 ΔAPTT 相关的可能因素，即两种试剂测量值之间的差异。
为了阐明与 ΔAPTT 相关的因素，我们对 8324 个样本进行了多元回归分析，使用同时请求的所有 APTT 测试项目的临床实验室数据。为了确认从多元回归分析中提取的项目，我们将目标物质添加到混合血浆中，并使用两种 APTT 试剂进行测量。此外，通过添加磷脂，评估了对 APTT 测量系统的影响。
多元回归分析检测到白蛋白-球蛋白比（AGR）、C 反应蛋白（CRP）、血细胞比容和凝血酶原时间是与 ΔAPTT 相关的因素（p<0.001）。结果表明，当添加白蛋白以改变 AGR 时，没有观察到显著差异。然而，当添加 CRP 时，与 Thrombocheck APTT-SLA 相比，Coagpia APTT-n 中的 APTT 延长（p<0.001）。通过添加磷脂，这种延长被取消，表明 CRP 与磷脂的相互作用导致假性延长。
考虑到 CRP 在 Coagpia APTT-n 中的磷脂上的相互作用触发了 APTT 的假性延长，这导致了 APTT 的分离。
