Talstad I
Fürst Medical Laboratory, Oslo, Norway.
Haemostasis. 1996 Sep-Oct;26(5):266-75. doi: 10.1159/000217217.
The standardization of prothrombin time (PT) assays needs two steps: (1) calibration of PT assays towards a reference assay or reference thromboplastin, (2) correction of PT assays according to the calibration. The present recommended calibration by clotting times is favored for the linearity between assays; the clotting times of abnormal plasma are partly prolonged due to the protein induced by vitamin K absence (Pivka) inhibitor. Calibration by coagulation activities also demonstrated linearity between PT assays; the regression line for abnormal plasma deviated from the line of identity due to differences in sensitivity of assays for the Pivka inhibitor. The corrected PT assays demonstrated similar results using calibration by clotting time or coagulation activities, but the correction was simpler for coagulation activities. Patient plasma was the preferable material in calibration by clotting times as well as by coagulation activities. The corrections between the reference assay and other PT assays were equal to the differences in sensitivities for the Pivka inhibitor. The corrected PT assays did not differ from the reference assay by statistical analysis; any of the six PT assays tested might be used as reference assay.
凝血酶原时间（PT）检测的标准化需要两个步骤：（1）将PT检测校准至参考检测或参考凝血活酶；（2）根据校准结果对PT检测进行校正。目前推荐的通过凝血时间进行校准，有利于检测之间的线性关系；异常血浆的凝血时间部分延长是由于维生素K缺乏诱导蛋白（PIVKA）抑制剂所致。通过凝血活性进行校准也证明了PT检测之间的线性关系；由于对PIVKA抑制剂检测的敏感性差异，异常血浆的回归线偏离了恒等线。使用凝血时间或凝血活性进行校准，校正后的PT检测结果相似，但凝血活性的校正更简单。在通过凝血时间以及凝血活性进行校准时，患者血浆是首选材料。参考检测与其他PT检测之间的校正等于对PIVKA抑制剂敏感性的差异。经统计学分析，校正后的PT检测与参考检测无差异；所测试的六种PT检测中的任何一种都可用作参考检测。
