van den Besselaar A M
Department of Haematology, Leiden University Hospital, The Netherlands.
Arch Pathol Lab Med. 1994 Feb;118(2):145-9.
The response of the prothrombin time to oral anticoagulant treatment depends on the thromboplastin reagent and method of testing. A prothrombin time assay system may be characterized by its international sensitivity index (ISI) with which a coumarin-treated patient's international normalized ratio can be calculated. Both the anticoagulant (sodium oxalate or sodium citrate) and calcium chloride concentrations influenced the ISI. An ISI of 2.0 was obtained for Quick's prothrombin time assay using rabbit brain thromboplastin. Replacing rabbit brain by human brain thromboplastin (Aggeler's method) resulted in an ISI of 1.3. The results described herein are mainly of historical interest and may assist in the interpretation of anticoagulation intensity in early American recommendations.
凝血酶原时间对口服抗凝治疗的反应取决于凝血活酶试剂和检测方法。凝血酶原时间测定系统可用国际敏感指数（ISI）来表征，通过该指数可计算香豆素治疗患者的国际标准化比值。抗凝剂（草酸钠或柠檬酸钠）和氯化钙浓度均会影响国际敏感指数。使用兔脑凝血活酶进行Quick凝血酶原时间测定时，国际敏感指数为2.0。用人脑凝血活酶替代兔脑凝血活酶（Aggeler法），国际敏感指数为1.3。本文所述结果主要具有历史意义，可能有助于解读早期美国建议中的抗凝强度。
