Department of Pathology, University of Manitoba, Winnipeg, Manitoba, Canada.
Research Institute in Oncology and Hematology, CancerCare Manitoba, Winnipeg, Manitoba, Canada.
Int J Lab Hematol. 2019 Feb;41(1):133-140. doi: 10.1111/ijlh.12937. Epub 2018 Oct 25.
The "gold standard" diagnostic test for assessing in vitro platelet function, light transmission aggregometry (LTA), has limitations to application because of sample requirements. Whole blood or multiple electrode aggregometry (MEA) using the Multiplate analyzer (Roche Diagnostics) requires smaller blood volumes and less sample manipulation than LTA, making it an attractive clinical testing option. Direct comparisons of MEA with LTA for diagnosis of platelet aggregation abnormalities are few.
Ninety-nine patients (66 F/33 M; median age 26 [range 2-86] years), referred for initial laboratory evaluation of mucocutaneous bleeding, had parallel MEA/LTA testing. Concentrations of ADP, arachidonic acid (AA), collagen, and thrombin receptor-activating peptide (TRAP) that produced threshold responses in normal controls were used for testing patients.
Twenty-nine of the 99 patients (30%) had at least one abnormal agonist response by LTA; 15 of these patients had >1 abnormal agonist response. Thirty-six patients (36%) had at least one abnormal agonist response by MEA; 27 had >1 abnormal agonist response. Sensitivity/specificity of MEA relative to LTA: ADP, 0.70/0.72; AA, 0.71/0.85; collagen, 0.85/0.71; TRAP 0.25/0.84. Negative predictive values (NPVs) for MEA relative to LTA: ADP, 0.90; AA, 0.93; collagen, 0.97; TRAP, 0.96.
Specific abnormal results of MEA testing did not adequately predict specific abnormalities in LTA testing using threshold agonist concentrations. However, favorable NPVs suggest that MEA may be useful in screening patients for platelet aggregation abnormalities; those with normal MEA results not requiring further diagnostic testing by LTA.
评估体外血小板功能的“金标准”诊断测试——光传输聚集测定法（LTA），由于其样本要求，存在应用局限性。全血或使用 Multiplate 分析仪（罗氏诊断公司）的多电极聚集测定法（MEA）需要的样本量更小，样本操作也更少，因此成为一种有吸引力的临床检测选择。MEA 与 LTA 用于诊断血小板聚集异常的直接比较很少。
99 例患者（66 例女性/33 例男性；中位年龄 26 岁[范围 2-86 岁]），因黏膜皮肤出血的初始实验室评估而转介，并行 MEA/LTA 检测。在正常对照中产生阈值反应的 ADP、花生四烯酸（AA）、胶原和血栓素受体激活肽（TRAP）浓度用于检测患者。
99 例患者中，29 例（30%）的 LTA 至少有一个异常激动剂反应；其中 15 例患者有>1 个异常激动剂反应。36 例患者（36%）的 MEA 至少有一个异常激动剂反应；其中 27 例患者有>1 个异常激动剂反应。MEA 相对于 LTA 的敏感性/特异性：ADP，0.70/0.72；AA，0.71/0.85；胶原，0.85/0.71；TRAP，0.25/0.84。MEA 相对于 LTA 的阴性预测值（NPV）：ADP，0.90；AA，0.93；胶原，0.97；TRAP，0.96。
MEA 检测的特定异常结果不能充分预测使用阈值激动剂浓度的 LTA 检测中的特定异常。然而，有利的 NPV 表明 MEA 可能有助于筛选血小板聚集异常的患者；那些 MEA 结果正常的患者不需要进一步的 LTA 诊断性检测。
