背景:狼疮抗凝剂(LA)是一种干扰一种或多种体外凝血反应的抗体,依赖于与蛋白质-磷脂复合物的相互作用。对于LA诊断,混合试验被认为可用于区分抑制剂与因子缺乏。然而,循环抗凝剂(ICA)在活化部分凝血活酶时间(APTT)混合试验中的有效性和指数尚未得到充分研究,关于华法林的影响的信息很少,肝素,和ICA上的血友病血浆。我们通过调查该指数与国际标准化比率(INR)的相关性来评估ICA的有用性,肝素浓度,血友病患者的VIII因子活性。
方法:我们检查了28例LA阳性患者的样本,23接受华法林,19接受普通肝素,和29患有A型血友病,以及61个正常样本。APTT-SLA,肌动蛋白FSL,APTT-SP,和PTT-LA用作本研究的试剂。
结果:ICA和INR之间的相关系数值,肝素浓度,和因子VIII活性范围分别为0.031-0.342、0.764-0.843和0.564-0.754,4种试剂。LA阳性样本的ICA值明显高于正常样本,华法林,肝素,和所有APTT试剂的血友病样本。具有高于约0.5U/ml的高肝素浓度的样品显示ICA值大于15。
结论:ICA能够将LA阳性样本与正常样本区分开,华法林,血友病样本,但不是肝素样本.从APTT凝血时间计算的ICA对LA诊断有用。
BACKGROUND: Lupus anticoagulant (LA) is an antibody that interferes with one or more in vitro coagulation reactions, which are dependent on interactions with protein-phospholipid complexes. For LA diagnosis, a mixing test is considered useful for differentiating the inhibitor from a factor deficiency. However, the usefulness and the index of circulating anticoagulant (ICA) in a mixing test with activated partial thromboplastin time (APTT) has not been adequately investigated, and there is scant information regarding the effects of warfarin, heparin, and hemophilia plasma on ICA. We evaluated the usefulness of ICA by investigating the correlation of that index with international normalized ratio (INR), heparin concentration, and factor VIII activity in hemophilia patients.
METHODS: We examined samples from 28 patients positive for LA, 23 receiving warfarin, 19 receiving unfractionated heparin, and 29 with hemophilia A, as well as 61 normal samples. APTT-SLA, Actin FSL, APTT-SP, and PTT-LA were used as reagents in this study.
RESULTS: The correlation coefficient values between ICA and INR, heparin concentration, and factor VIII activity ranged from 0.031-0.342, 0.764-0.843, and 0.564-0.754, respectively, with the 4 reagents. The ICA values for the LA-positive samples were significantly higher than for the normal, warfarin, heparin, and hemophilia samples with all APTT reagents. Samples with a high heparin concentration above approximately 0.5U/ml showed ICA values greater than 15.
CONCLUSIONS: ICA was able to distinguish LA-positive samples from the normal, warfarin, and hemophilia samples, but not heparin samples. ICA calculated from APTT clotting time is useful for LA diagnosis.