Standardization of the measuring method for lupus anticoagulant (LA)

探讨血栓形成危险因素狼疮抗凝物（LA）测定方法的标准化。通过以1500 x g单次离心15分钟获得的血浆（残留血小板：小于3，000/uL）对于LA试验非常有用，因为在残留血小板超过1，200/uL的血浆中LA活性发生显著变化。另一方面，根据我们使用具有相同磷脂条件的APTT试剂和二氧化硅或鞣花酸作为活化剂的LA活性的结果，APTT试剂对LA的灵敏度取决于磷脂浓度而不是活化剂。在APTT交叉混合试验中，10%和20%比例的LA血浆和50%比例的因子VIII缺乏血浆或抑制剂阳性血浆产生最佳结果。因此，建议对0、10、20、50、100%的5种不同混合比例的患者血浆进行混合试验。

Standardization of the measuring method for lupus anticoagulant (LA), which is a risk factor of thrombosis, was investigated. The plasma (residual platelets: less than 3,000/uL) obtained by single centrifugation at 1500 x g for 15 minutes, is quite useful for LA tests, because LA activity was significantly changed in plasma with more than 1,200/uL of residual platelets. On the other hand, the sensitivity of APTT reagents for LA is dependent on phospholipid concentration and not the activator, according to our results of LA activity using APTT reagents with same phospholipid condition and silica or ellagic acid as a activator. In an APTT cross-mixing test, 10% and 20% ratio of LA plasma and a 50% ratio of factor VIII deficient plasma or inhibitor positive plasma produced optimum results. Therefore, it is recommended to carry out the mixing test on 5 different mixing ratios of 0, 10, 20, 50, 100% of patient plasma.