Tripodi A, Chantarangkul V, Arbini A A, Moia M, Mannucci P M
Angelo Bianchi Bonomi Hemophilia and Thrombosis Center, IRCCS Maggiore Hospital, Milano, Italy.
Thromb Haemost. 1993 Aug 2;70(2):286-8.
Hirudin prolongs the APTT when added to normal plasma and the extent of prolongation depends on the type of reagent used. The aim of this study was to compare the dose-response curves of 10 widely used APTT reagents for linearity and parallelism. On each of 10 working days a normal pooled plasma was mixed with increasing amounts of recombinant hirudin (HBW023) ranging from 0 to 5 micrograms/ml and tested for APTT by photo optical coagulometer. Within each working day, clotting times were measured in duplicate and the order of testing with each reagent was changed every day. Results were expressed as ratios of clotting times with hirudin to clotting times without hirudin, and the values plotted against the hirudin concentration on a log-log scale. The dose-response curves for all reagents were linear over 0.3-1.2 micrograms/ml. The reagent-related slopes ranged from 0.225 +/- 0.003 to 0.303 +/- 0.003 (mean +/- SE) and were significantly different. Precision studies indicated that the least sensitive reagent was also the least precise. These findings indicate that the clotting time values obtained for patients treated with hirudin will vary depending on the APTT reagent used.
水蛭素添加到正常血浆中时会延长活化部分凝血活酶时间（APTT），延长程度取决于所用试剂的类型。本研究的目的是比较10种广泛使用的APTT试剂的剂量反应曲线的线性和平行性。在10个工作日中的每一天，将正常混合血浆与重组水蛭素（HBW023）按0至5微克/毫升的量递增混合，并用光学凝血仪检测APTT。在每个工作日内，凝血时间进行双份测量，且每天改变每种试剂的检测顺序。结果表示为有水蛭素时的凝血时间与无水蛭素时的凝血时间之比，并将这些值在对数-对数尺度上相对于水蛭素浓度作图。所有试剂的剂量反应曲线在0.3至1.2微克/毫升范围内呈线性。试剂相关的斜率范围为0.225±0.003至0.303±0.003（平均值±标准误），且有显著差异。精密度研究表明，最不敏感的试剂也是最不精确的。这些发现表明，接受水蛭素治疗的患者所获得的凝血时间值将因所用的APTT试剂而异。
