McKernan A, Thomson J M, Poller L
UK Reference Laboratory for Anticoagulant Reagents and Control, Withington Hospital, Manchester.
Clin Lab Haematol. 1988;10(1):63-71. doi: 10.1111/j.1365-2257.1988.tb01154.x.
The reliability of the international normalized ratios (INR) system in the induction phase of coumarin administration has been studied in 15 serial patients over the first 7-40 days of treatment (mean 13.1). The INR results obtained with a variety of thromboplastin reagents have been compared with those obtained with the WHO second primary IRP, BCT/253. A wide divergence of INR values was observed with the various thromboplastins on each day of testing. INR values cannot therefore be relied upon with some of these reagents in the early days of anticoagulant treatment. This probably arises from the difference in responses of the thromboplastins to depression of vitamin K-dependent clotting factors. Consistent deviations from the IRP suggested that additional error may be due to inaccurate calibration of their products by the manufacturers. When the slopes of the sensitivity of the individual reagents to clotting factors II, VII and X were compared, however, results overall more closely approximated to those of the IRP when the INR were substituted for simple prothrombin ratios.
在香豆素给药诱导期，对15例连续患者在治疗的前7至40天（平均13.1天）的国际标准化比值（INR）系统可靠性进行了研究。将使用多种凝血活酶试剂获得的INR结果与使用世界卫生组织第二原发性国际参考制剂BCT/253获得的结果进行了比较。在测试的每一天，使用各种凝血活酶观察到INR值存在很大差异。因此，在抗凝治疗早期，不能依靠其中一些试剂的INR值。这可能是由于凝血活酶对维生素K依赖凝血因子降低的反应不同所致。与国际参考制剂的持续偏差表明，额外的误差可能是由于制造商对其产品校准不准确。然而，当比较各试剂对凝血因子II、VII和X的敏感性斜率时，用INR代替简单凝血酶原比值时，总体结果更接近国际参考制剂的结果。
