Duncan E M, Casey C R, Duncan B M, Lloyd J V
Haemostasis Section, Institute of Medical and Veterinary Science, Adelaide, Australia.
Thromb Haemost. 1994 Jul;72(1):84-8.
The aim of this study was to determine whether the concentration of trisodium citrate used to anticoagulate blood has an effect on the INR of the sample and the ISI of the thromboplastin. Five thromboplastins including and Australian reference material were used to measure the prothrombin time of normal and patient samples collected into two concentrations of trisodium citrate--109 mM and 129 mM. There was no effect of citrate concentration on the INRs determined with the reference material. However for the other four thromboplastins there was a significant difference between INRs for the two citrate groups. The prothrombin times of the samples collected into 129 mM were longer than those collected into 109 mM. This difference was only slight in normal plasma but more marked in patients receiving oral anticoagulants, causing the INRs for patient plasmas collected into 129 mM citrate to be higher then the corresponding samples collected into 109 mM citrate. From orthogonal regression of log prothrombin times by the reference method against each thromboplastin, we found that the ISI for each thromboplastin was approximately 10% lower when determined with samples collected into 129 mM citrate than with samples collected into 109 mM. These results suggest that the concentration of trisodium citrate used for collection of blood samples can affect the calculation of the INR and the calibration of the ISI of thromboplastin. This was found both for commercial thromboplastins prepared by tissue extraction and for a recombinant tissue factor.
本研究的目的是确定用于血液抗凝的枸橼酸钠浓度是否会对样本的国际标准化比值（INR）和凝血活酶的国际敏感度指数（ISI）产生影响。使用包括一种澳大利亚参考物质在内的五种凝血活酶，来测定采集到两种浓度枸橼酸钠（109 mM和129 mM）中的正常样本和患者样本的凝血酶原时间。枸橼酸钠浓度对用参考物质测定的INR没有影响。然而，对于其他四种凝血活酶，两个枸橼酸钠组的INR之间存在显著差异。采集到129 mM枸橼酸钠中的样本的凝血酶原时间比采集到109 mM中的样本长。这种差异在正常血浆中仅轻微，但在接受口服抗凝剂治疗的患者中更明显，导致采集到129 mM枸橼酸钠中的患者血浆的INR高于采集到109 mM枸橼酸钠中的相应样本。通过参考方法对每种凝血活酶的对数凝血酶原时间进行正交回归分析，我们发现，与采集到109 mM枸橼酸钠中的样本相比，用采集到129 mM枸橼酸钠中的样本测定时，每种凝血活酶的ISI约低10%。这些结果表明，用于采集血样的枸橼酸钠浓度会影响INR的计算和凝血活酶ISI的校准。这在通过组织提取制备的商业凝血活酶和重组组织因子中均有发现。
