Blois Shauna L, Banerjee Amrita, Wood R Darren
Department of Clinical Studies, Ontario Veterinary College, University of Guelph, Guelph, Ontario, Canada.
Vet Clin Pathol. 2012 Jun;41(2):223-7. doi: 10.1111/j.1939-165X.2012.00419.x. Epub 2012 Mar 27.
Thrombelastography (TEG) permits analysis of clot formation but it is not specific for platelet activity. TEG PlateletMapping (TEG-PM) is a modification of TEG that uses adenosine diphosphate (ADP) and arachidonic acid (AA) as platelet agonists to define the contribution of platelets to clot formation.
The objectives of this study were to determine values for TEG-PM in healthy cats and the interassay variation of TEG-PM.
TEG-PM analysis was performed on blood specimens collected from 12 healthy cats and was repeated using a second blood specimen collected 2 hours later. Maximum amplitudes generated by thrombin (MA(thrombin)), fibrin (MA(fibrin)), ADP-stimulated platelet activity (MA(ADP)), and AA-stimulated platelet activity (MA(AA)) were recorded.
Mean ± SD for MA(thrombin) was 51.1 ± 8.5 mm, for MA(fibrin) was 32.3 ± 17.7 mm, for MA(ADP) was 32.3 ± 15.0 mm, and for MA(AA) was 24.5 ± 12.2 mm. Mean MA(ADP) and MA(fibrin) were not significantly different, whereas mean MA(AA) was significantly lower than mean MA(fibrin). Results from the first and second specimens were not significantly different. Correlation between the first and second specimens was moderate for MA(thrombin), MA(fibrin), and MA(ADP), but was poor for MA(AA). A high degree of variability (coefficient of variation 47.7-60.0%) was observed for MA(fibrin), MA(ADP), and MA(AA).
As MA(ADP) and MA(AA) (AA) were the same as or lower than MA(fibrin), a valid baseline to determine platelet-stimulated clot formation could not be established. Considerable interassay variation and wide intervals for MA(fibrin), MA(ADP), and MA(AA) values in this study indicate that TEG-PM should be used cautiously in feline patients. Several preanalytical factors should be examined in further detail.
血栓弹力图（TEG）可用于分析血凝块形成，但它对血小板活性并不具有特异性。TEG血小板功能分析（TEG-PM）是TEG的一种改良方法，它使用二磷酸腺苷（ADP）和花生四烯酸（AA）作为血小板激动剂来确定血小板对血凝块形成的贡献。
本研究的目的是确定健康猫的TEG-PM值以及TEG-PM的批间差异。
对从12只健康猫采集的血液标本进行TEG-PM分析，并在2小时后采集的第二份血液标本上重复进行。记录凝血酶产生的最大振幅（MA(凝血酶)）、纤维蛋白（MA(纤维蛋白)）、ADP刺激的血小板活性（MA(ADP)）和AA刺激的血小板活性（MA(AA)）。
MA(凝血酶)的平均值±标准差为51.1±8.5毫米，MA(纤维蛋白)为32.3±17.7毫米，MA(ADP)为32.3±15.0毫米，MA(AA)为24.5±12.2毫米。MA(ADP)和MA(纤维蛋白)的平均值无显著差异，而MA(AA)的平均值显著低于MA(纤维蛋白)的平均值。第一份和第二份标本的结果无显著差异。第一份和第二份标本之间，MA(凝血酶)、MA(纤维蛋白)和MA(ADP)的相关性为中等，但MA(AA)的相关性较差。观察到MA(纤维蛋白)、MA(ADP)和MA(AA)具有高度变异性（变异系数为47.7 - 60.0%）。
由于MA(ADP)和MA(AA)与MA(纤维蛋白)相同或更低，因此无法建立用于确定血小板刺激的血凝块形成的有效基线。本研究中MA(纤维蛋白)、MA(ADP)和MA(AA)值存在相当大的批间差异和较宽的区间，这表明在猫科动物患者中应谨慎使用TEG-PM。应进一步详细研究几个分析前因素。
