Makris P E, Pithara E
A' Prop, Med Clinic AHEPA University Hospital, Thessaloniki, Makedonia-Greece.
Int Angiol. 1998 Jun;17(2):69-79.
Until now, there has been no reliable method for the monitoring low molecular weight heparin (LMWH) therapy. Based on our observations of the coagulant activity of pseudoserum obtained after clotting of recalcified plasma from patients who were treated with LMWH, we were led to develop a new global clotting assay for the monitoring of this treatment. Methods description. After performing Howell time on PPP, samples were incubated for 30 min in 37 degrees C and they were then centrifuged for 10 min 0.2 ml of this pseudoserum is added to 0.2 ml of citrated normal plasma. Pseudoserum triggered coagulation of normal plasma and the time of new clot formation is expressed in seconds. This assay was called ATHU-test (AHEPA Thromb Haem Unit). We tested 21 normal subjects a in order to define the normal mean value and the range of the method. b) We also checked the reproducibility of the method by repeating the ATHU-test 17 times on the same normal plasma. c) We performed in vitro experiments to study its reliability and we added increasing concentrations using given doses of enoxaparine (4, 8, 12, 16 mg/ml) or fraxiparine (1.5, 3.0, 4.5, 6 u aXa/ml) which was added in vitro to normal plasma confirming the proportional linear regression between duration of our test and the amount of LMWH. Finally d) we checked on the therapy response and the LMWH levels in blood for thrombophiliacs. Results. a) NP, n=21, X=138.6+/-41.1, range 75-225 sec which means that values >X+/-3S=261.9 are distinctively pathological. b) The reproducibility of the method is acceptable, CV=9%. c) It is confirmed that in vitro addition of precautionary doses of LMWH (1.5 u aXa/ml) exceeds the coagulation time of ATHU-test up to 300 sec and it follows a distinctively proportional relationship. d) The monitoring of 20 thrombophiliacs for 2 months proved that: i) All their test times were between 4-15 min. The more we approach the value of 15 min the more danger there is of haemorrhage while, on the contrary, the more values approach 4 min the more the danger of rethrombosis increases. We present the ATHU-test, a simple test which has been used for 6 months now by our Unit, in order to control the LMWH therapy for patients with thromboembolic diseases. The ATHU-test's reproducibility and its small range of normal values, the distinct relationship between therapeutic doses and therapeutic clinical results, as well as the in vitro proof of the linear regression between the coagulation time and the containing amount of LMWH, are likely to establish a new method of choice for the monitoring of LMWH therapy.
到目前为止，尚无可靠的方法来监测低分子量肝素（LMWH）治疗。基于我们对接受LMWH治疗患者的重新钙化血浆凝血后获得的假血清凝血活性的观察，我们开发了一种新的整体凝血测定法来监测这种治疗。方法描述。在对乏血小板血浆（PPP）进行豪厄尔时间测定后，将样本在37℃下孵育30分钟，然后离心10分钟。将0.2毫升这种假血清加入到0.2毫升枸橼酸化正常血浆中。假血清引发正常血浆凝血，新凝块形成的时间以秒表示。该测定法称为ATHU试验（AHEPA血栓与血液学单位试验）。我们对21名正常受试者进行了测试，以便确定该方法的正常平均值和范围。b）我们还通过在同一正常血浆上重复进行17次ATHU试验来检查该方法的可重复性。c）我们进行了体外实验以研究其可靠性，并使用给定剂量的依诺肝素（4、8、12、16毫克/毫升）或速碧林（1.5、3.0、4.5、6抗Xa单位/毫升）向正常血浆中体外添加递增浓度，证实了我们试验的持续时间与LMWH量之间的比例线性回归。最后d）我们检查了血栓形成倾向患者的治疗反应和血液中的LMWH水平。结果。a）正常受试者（NP），n = 21，X = 138.6±41.1，范围75 - 225秒，这意味着值>X±3S = 261.9明显为病理性。b）该方法的可重复性是可接受的，变异系数（CV）= 9%。c）证实体外添加预防性剂量的LMWH（1.5抗Xa单位/毫升）可使ATHU试验的凝血时间延长至300秒，且呈现明显的比例关系。d）对20名血栓形成倾向患者进行2个月的监测证明：i）他们所有的测试时间都在4 - 15分钟之间。越接近15分钟的值，出血风险越高，相反，越接近4分钟的值，再血栓形成的风险增加越多。我们介绍ATHU试验，这是一种简单的试验，我们科室现已使用6个月，用于控制血栓栓塞性疾病患者的LMWH治疗。ATHU试验的可重复性、其较小的正常数值范围、治疗剂量与治疗临床结果之间的明显关系，以及凝血时间与LMWH含量之间线性回归的体外证据，可能会确立一种监测LMWH治疗的新的首选方法。
