Stiegler H, Fischer Y, Vazquez-Jimenez J F, Graf J, Filzmaier K, Fausten B, Janssens U, Gressner A M, Kunz D
Institut für Klinische Chemie und Pathobiochemie, Medizinische Klinik I, and Klinik für Thorax-, Herz- und Gefässchirurgie, Universitätsklinikum der RWTH Aachen, 52074 Aachen, Germany.
Clin Chem. 2000 Sep;46(9):1338-44.
The use of plasma rather than serum for determination of cardiac troponins can improve turnaround time and potentially avoid incomplete serum separation that may produce falsely increased results. We investigated the influence of incomplete serum separation and the effect of heparin-plasma on cardiac troponin concentrations.
Serum and heparin-plasma samples were drawn simultaneously from 100 patients (50 patients with acute coronary syndrome and 50 patients after open heart surgery) and measured on three different analytical systems, two for determination of cardiac troponin I (cTnI; Abbott AxSYM and Bayer ACS:Centaur) and one for cardiac troponin T (cTnT; Roche Elecsys cTnT STAT). Serum samples were reanalyzed after a second centrifugation to assess the influence of incomplete serum separation.
Mean results (+/- 95% confidence interval) in heparin-plasma compared with serum were 101% +/- 2% (AxSYM cTnI), 94% +/- 3% (ACS:Centaur cTnI), and 99% +/- 3% (Elecsys cTnT). Differences >20% were seen in 11% of results on the ACS:Centaur, 9% of results on Elecsys cTnT, and 2% of results on the AxSYM. For the Elecsys cTnT assay, the magnitude of the difference between serum and plasma was independent of the absolute concentration and confined to individual samples, and was reversed by treatment with heparinase. A second centrifugation had no effect on serum results by any of the assays.
The concentrations of troponins measured in heparin-plasma are markedly lower than in serum in some cases.
使用血浆而非血清来测定心肌肌钙蛋白可缩短周转时间，并有可能避免因血清分离不完全而导致结果假性升高。我们研究了血清分离不完全的影响以及肝素化血浆对心肌肌钙蛋白浓度的影响。
同时从100例患者（50例急性冠状动脉综合征患者和50例心脏直视手术后患者）采集血清和肝素化血浆样本，并在三种不同的分析系统上进行检测，其中两种用于测定心肌肌钙蛋白I（cTnI；雅培AxSYM和拜耳ACS：Centaur），一种用于测定心肌肌钙蛋白T（cTnT；罗氏Elecsys cTnT STAT）。对血清样本进行二次离心后重新检测，以评估血清分离不完全的影响。
与血清相比，肝素化血浆中的平均结果（±95%置信区间）分别为101%±2%（AxSYM cTnI）、94%±3%（ACS：Centaur cTnI）和99%±3%（Elecsys cTnT）。在ACS：Centaur上，11%的结果差异>20%；在Elecsys cTnT上，9%的结果差异>20%；在AxSYM上，2%的结果差异>20%。对于Elecsys cTnT检测，血清和血浆之间差异的大小与绝对浓度无关，且仅限于个别样本，用肝素酶处理可使其逆转。二次离心对任何检测方法的血清结果均无影响。
在某些情况下，肝素化血浆中测得的肌钙蛋白浓度明显低于血清中的浓度。
