Kusch M, Seitz R, König H
Paul Ehrlich Institut, Langen, Germany.
Thromb Haemost. 1998 Apr;79(4):778-83.
A very sensitive and highly reliable test system for the detection of activated coagulation factor IX (FIXa) has been established. This assay system is based on the cleavage of a fluorogenic substrate by activated factor X (FXa) which is generated by FIXa. This assay can be used to process a large number of samples at a time and, being based on the convenient microtiter plate format, can easily be adapted to automated processing for routine screening of large sample numbers. With this assay at hand we determined the FIXa content of different commercially available therapeutic FIX sources, such as high purity FIX (HPFIX) and prothrombin complex concentrates (PCC). Here we demonstrate that PCC from several suppliers do not contain significantly higher levels of FIXa as compared to HPFIX from the same supplier. In fact, there is a tendency for HPFIX to contain more FIXa than PCC. Moreover, HPFIX from certain manufacturers who do not produce PCC are characterized by an exceptionally high content of FIXa. Therefore, the higher thrombogenic potential of PCC which is well documented clinically cannot be explained solely -- if at all -- by an increased content of FIXa. Rather, it will be necessary to identify other components responsible for this phenomenon.
已建立一种用于检测活化凝血因子IX（FIXa）的极其灵敏且高度可靠的检测系统。该检测系统基于FIXa生成的活化因子X（FXa）对荧光底物的切割。此检测方法可一次处理大量样本，并且基于便捷的微量滴定板形式，能够轻松适应自动化处理，用于对大量样本进行常规筛查。利用该检测方法，我们测定了不同市售治疗性FIX来源的FIXa含量，例如高纯度FIX（HPFIX）和凝血酶原复合物浓缩物（PCC）。在此我们证明，与同一供应商的HPFIX相比，来自多个供应商的PCC所含FIXa水平并未显著更高。事实上，存在HPFIX比PCC含有更多FIXa的趋势。此外，某些不生产PCC的制造商生产的HPFIX具有异常高的FIXa含量。因此，临床上有充分记录的PCC较高的血栓形成潜力，若要解释的话，不能仅由FIXa含量增加来解释。相反，有必要识别造成这种现象的其他成分。
