Lippi Giuseppe, Pavesi Fernanda, Pipitone Silvia
Laboratory of Clinical Chemistry and Hematology, Academic Hospital of Parma, Parma, Italy.
Blood Coagul Fibrinolysis. 2015 Mar;26(2):235-7. doi: 10.1097/MBC.0000000000000220.
The clinical applications of mean platelet volume (MPV) have recently broadened far beyond the differential diagnosis of platelet (PLT) disorders to embrace diagnosis and prognostication of a variety of thrombotic conditions. As the potential usefulness of this simple and inexpensive parameter may be challenged by instrument heterogeneity, we investigated the degree of analytical quality and interinstrument comparability. One hundred consecutive inpatient samples were simultaneously assessed on Abbott Sapphire, Mindray BC6800, Siemens Advia 2120, and Sysmex XE5000. The within-run imprecision of the four hematological analyzers was also assessed according to the Clinical and Laboratory Standards Institute document EP5-A2. The imprecision of PLT count ranged between 1.4 and 4.3%, and hence was always within the desirable quality specifications. The within-run imprecision of MPV ranged between 1.1 and 3.8%, and hence was also within the desirable quality specifications. The optical and impedance measurements displayed excellent correlations. Overall, the PLT count exhibited a modest instrumental variation, with bias always within the desirable quality specifications. A large bias was instead recorded for MPV, with between-instrument variations exceeding the desirable quality specifications in five out of six interinstrumental comparisons. No significant correlation was also observed between PLT count and MPV with any of the instruments tested. These results attest that although there is an optimal degree of analytical quality and comparability for PLT counting among different hemocytometers, the harmonization of MPV is poor, thus making the adoption of universal cutoffs virtually impossible.
平均血小板体积（MPV）的临床应用近来已大幅拓展，远远超出了血小板（PLT）疾病的鉴别诊断范围，涵盖了多种血栓形成性疾病的诊断和预后评估。由于这个简单且成本低廉的参数的潜在效用可能受到仪器异质性的挑战，我们研究了其分析质量程度和仪器间的可比性。对100份连续的住院患者样本同时在雅培 Sapphire、迈瑞 BC6800、西门子 Advia 2120 和Sysmex XE5000 上进行评估。还根据临床和实验室标准协会文件 EP5 - A2 评估了这四台血液分析仪的批内不精密度。PLT 计数的不精密度在 1.4%至 4.3%之间，因此始终在理想的质量规格范围内。MPV 的批内不精密度在 1.1%至 3.8%之间，因此也在理想的质量规格范围内。光学和阻抗测量显示出极好的相关性。总体而言，PLT 计数表现出适度的仪器间差异，偏差始终在理想的质量规格范围内。相反，MPV 记录到较大偏差，在六次仪器间比较中有五次仪器间差异超过了理想的质量规格。在所测试的任何仪器中，PLT 计数和 MPV 之间也未观察到显著相关性。这些结果证明，尽管不同血细胞分析仪之间 PLT 计数存在最佳程度的分析质量和可比性，但 MPV 的一致性较差，因此几乎不可能采用通用的临界值。
