Petrucci Giovanna, Rizzi Alessandro, Bellavia Simone, Dentali Francesco, Frisullo Giovanni, Pitocco Dario, Ranalli Paola, Rizzo Pier Andrea, Scala Irene, Silingardi Mauro, Zagarrì Elisa, Gussoni Gualberto, Rocca Bianca
Department of Healthcare Surveillance and Bioethics, Section of Pharmacology, Catholic University School of Medicine, Rome, Italy.
Fondazione Policlinico Universitario A. Gemelli Istituto di Ricovero e Cura a Carattere Scientifico, Rome, Italy.
Res Pract Thromb Haemost. 2024 Nov 12;8(8):102623. doi: 10.1016/j.rpth.2024.102623. eCollection 2024 Nov.
Serum thromboxane B (sTXB) is a validated biomarker of low-dose aspirin pharmacodynamics. In the original method, nonanticoagulated blood samples must be incubated at 37 °C immediately after withdrawal, centrifuged and serum supernatant should be frozen until assayed. Timely completion of all preanalytical steps may affect the feasibility and quality of sTXB measurements. The storage duration of frozen serum can also affect sTXB stability.
We assessed the stability of sTXB in clotted blood samples stored at 4 °C before further processing and in sera stored at -40 °C for over a decade.
Venous whole blood withdrawn from individuals on chronic low-dose aspirin was dispensed in different tubes and immediately incubated at 37 °C for 1 hour. The reference tube was promptly processed following the original protocol; the remaining tubes were stored at 4 °C for 12 to 72 hours before further processing. Sera stored at a controlled -40 °C temperature for <1 to 15 years were reassayed. Values within the interassay variation limits (±9%) vs baseline were considered acceptable.
Baseline sTXB values (median, 5.4 ng/mL; IQR, 2.4-13.4 ng/mL; = 40) were comparable with those in samples at 4 °C up to 48 hours (median, 97% [IQR, 86%-104%] of the reference; = 26), but at 72 hours, the variability exceeded the interassay variation. Thromboxane B levels were stable in frozen sera for up to 10 years (median, 101% [IQR, 87%-108%] of the reference; = 32) but decreased significantly afterward (median, 87% [IQR, 74%-109%] at 15 years; = .005; = 32).
Thromboxane B is stable in clotted blood samples stored at 4 °C for up to 48 hours before further processing and in serum samples stored at -40 °C over 10 years.
血清血栓素B（sTXB）是低剂量阿司匹林药效学的一种经过验证的生物标志物。在原方法中，未抗凝的血样在采集后必须立即在37°C下孵育，离心后血清上清液应冷冻保存直至检测。所有分析前步骤的及时完成可能会影响sTXB测量的可行性和质量。冷冻血清的保存时间也会影响sTXB的稳定性。
我们评估了在进一步处理前保存在4°C的凝血样本以及保存在-40°C超过十年的血清中sTXB的稳定性。
从服用慢性低剂量阿司匹林的个体中采集的静脉全血分装到不同试管中，并立即在37°C下孵育1小时。参照管按照原方案立即进行处理；其余试管在进一步处理前在4°C下保存12至72小时。对保存在-40°C受控温度下1至15年的血清重新进行检测。测定值在批间变异限度（±9%）内相对于基线值被认为是可接受的。
基线sTXB值（中位数为5.4 ng/mL；四分位间距为2.4 - 13.4 ng/mL；n = 40）与在4°C下保存长达48小时的样本中的值相当（中位数为参照值的97% [四分位间距为86% - 104%]；n = 26），但在72小时时，变异性超过了批间变异。血栓素B水平在冷冻血清中长达10年保持稳定（中位数为参照值的101% [四分位间距为87% - 108%]；n = 32），但此后显著下降（15年时中位数为87% [四分位间距为74% - 109%]；P = 0.005；n = 32）。
在进一步处理前，血栓素B在保存在4°C的凝血样本中长达48小时以及在保存在-40°C超过10年的血清样本中是稳定的。
