Transfusion Center and Haematology Laboratory, Western Milan Area Hospital Consortium, Legnano General Hospital, Legnano, Italy.
Clinical Chemistry Unit, Maggiore della Carità Hospital, Novara, Italy.
Biochem Med (Zagreb). 2018 Oct 15;28(3):030711. doi: 10.11613/BM.2018.030711.
Haemolysis is the leading cause of sample rejection in laboratory haemostasis. Most studies focused on artificially haemolysed samples. The aim of this study was a prospective assessment of spontaneous haemolysis on haemostasis tests, by comparing results of haemolysed (H) new, non-haemolysed (NH) specimens, collected within 4hrs. As new coagulometers can identify interfering substances, visual assessment of haemolysis was also compared with instrumental haemolysis index and stratified in subclasses.
Two hundred and sixty nine paired samples were collected and analysed using ACL TOP750-CTS (Instrumentation Laboratory, Bedford, USA), for prothrombin time (PT), activated partial thromboplastin time (aPTT), D-Dimer (DD), fibrinogen (Fib) and antithrombin (AT). Bias between H and NH was calculated and compared with the respective critical difference (CD).
Mean bias was - 0.1 s for PT (P = 0.057), - 1.1 s for aPTT (P < 0.001), 1025 ng/mL for DD (P < 0.001), - 0.04 g/L for Fib (P = 0.258) and 1.4% for AT (P = 0.013). Bias exceeding the CD varied according to the method, with larger differences for aPTT (36.1%) and DD (17.1%) and < 8% for PT, Fib and AT. No correlation emerged between free haemoglobin values and difference in haemostasis tests in H and NH samples for any tests. Moderate/severe haemolysis involved > 95% of samples. The agreement between visual assessment and instrumental evaluation of haemolysis was 0.62.
Spurious haemolysis deeply influences aPTT and DD, and to a lesser extent AT and Fib. Prothrombin time seems only slightly influenced, suggesting that PT can be accepted also in haemolysed samples. Although a good inter-observer correlation of haemolysis evaluation was found, the instrumental assessment of haemolysis seems recommendable.
溶血是实验室止血中样本拒收的主要原因。大多数研究都集中在人为溶血的样本上。本研究的目的是通过比较在 4 小时内采集的溶血（H）和非溶血（NH）新样本的止血试验结果，对自发性溶血进行前瞻性评估。由于新型凝血仪可以识别干扰物质，因此还比较了溶血的目视评估与仪器溶血指数，并进行了亚分类。
共采集 269 对样本，使用 ACL TOP750-CTS（Instrumentation Laboratory，Bedford，USA）进行凝血酶原时间（PT）、活化部分凝血活酶时间（aPTT）、D-二聚体（DD）、纤维蛋白原（Fib）和抗凝血酶（AT）分析。计算 H 和 NH 之间的偏差，并与相应的临界差值（CD）进行比较。
PT 的平均偏差为-0.1 s（P = 0.057），aPTT 的平均偏差为-1.1 s（P < 0.001），DD 的平均偏差为 1025 ng/mL（P < 0.001），Fib 的平均偏差为-0.04 g/L（P = 0.258），AT 的平均偏差为 1.4%（P = 0.013）。根据方法的不同，CD 偏差变化较大，aPTT（36.1%）和 DD（17.1%）差异较大，而 PT、Fib 和 AT 差异小于 8%。在 H 和 NH 样本中，任何测试的游离血红蛋白值与止血测试之间的差异均无相关性。中度/重度溶血涉及超过 95%的样本。溶血的目视评估与仪器评估之间的一致性为 0.62。
假性溶血会严重影响 aPTT 和 DD，对 AT 和 Fib 的影响较小。PT 似乎只有轻微影响，提示即使在溶血样本中也可以接受 PT。虽然发现溶血评估的观察者间相关性较好，但推荐使用仪器评估溶血。
