Department of Hemostaseology and Hemophilia Center, University Hospital Frankfurt, Theodor Stern Kai 7, 60596, Frankfurt, Germany.
Department of Hematology and Oncology, Johann Wolfgang Goethe University of Frankfurt, Theodor Stern Kai 7, 60596, Frankfurt am Main, Germany.
J Thromb Thrombolysis. 2020 Oct;50(3):628-631. doi: 10.1007/s11239-020-02086-8.
Thrombotic thrombocytopenic purpura (TTP) is a life-threatening thrombotic microangiopathy caused by severely reduced activity of the von-Willebrand factor-cleaving protease ADAMTS13, mainly caused by anti-ADAMTS-13 antibodies. Although several test systems for ADAMTS13 measurement exist, long turn-around times hamper the usability in daily practice. We performed a method comparison study for two commercially available ADAMTS13 assays and evaluated the agreement between the fully-automated rapid turn-over HemosIL AcuStar ADAMTS13 Activity assay and the manually performed TECHNOZYM ADAMTS-13 Activity assay. Twenty-four paired test samples derived from 10 consecutively recruited patients (n = 8, acquired TTP; n = 1, atypical hemolytic uremic syndrome; n = 1, control), of which nine test samples were collected in case of clinically apparent TTP and 13 samples were collected from TTP patients in clinical remission were included. Overall correlation between the TECHNOZYM and AcuStar assay was good with a Pearson R of 0.93 (p < 0.001). Agreement between the assays assessed with the Passing-Bablok analysis showed high agreement with an Intercept of - 2.56 (95% confidence interval [CI], - 5.07 to - 0.86) and Slope of 1.04 (95% CI 0.84-1.17). The absolute mean bias was 2.54% (standard difference [SD], 6.38%; 95% CI to 10.0-15.05%). Intra-method reliability was high with an absolute mean bias of - 0.13% (SD 3.21%; 95% CI to 6.42-6.16%). The observer agreement for categorial thresholds (> or < 10% ADAMTS3 activity) was kappa = 0.82 (95% CI 0.59-1.0). Conclusively, overall agreement between the testing methods was sufficient and we support previously published data suggesting the AcuStar assay being a valuable and accurate tool for ADAMTS13 activity testing and TTP diagnostics.
血栓性血小板减少性紫癜（TTP）是一种由 von-Willebrand 因子裂解蛋白酶 ADAMTS13 活性严重降低引起的致命性血栓性微血管病，主要由抗 ADAMTS-13 抗体引起。尽管存在几种 ADAMTS13 测量的测试系统，但周转时间长阻碍了其在日常实践中的可用性。我们对两种市售的 ADAMTS13 检测方法进行了方法比较研究，并评估了全自动快速周转 HemosIL AcuStar ADAMTS13 活性检测法与手动进行的 TECHNOZYM ADAMTS-13 活性检测法之间的一致性。从 10 名连续招募的患者中获得了 24 对测试样本（n=8，获得性 TTP；n=1，非典型溶血性尿毒症综合征；n=1，对照），其中 9 个测试样本是在临床上明显 TTP 时采集的，13 个样本是从 TTP 患者的临床缓解期采集的。TECHNOZYM 和 AcuStar 检测法之间的总体相关性良好，Pearson R 为 0.93（p<0.001）。用 Passing-Bablok 分析评估的检测法之间的一致性显示高度一致，截距为-2.56（95%置信区间[CI]，-5.07 至-0.86），斜率为 1.04（95% CI 0.84-1.17）。绝对平均偏差为 2.54%（标准差值[SD]，6.38%；95% CI 至 10.0-15.05%）。内方法可靠性高，绝对平均偏差为-0.13%（SD 3.21%；95% CI 至 6.42-6.16%）。类别阈值（>10% ADAMTS3 活性）的观察者一致性为 kappa=0.82（95% CI 0.59-1.0）。总的来说，测试方法之间的总体一致性是足够的，我们支持先前发表的数据，表明 AcuStar 检测法是 ADAMTS13 活性检测和 TTP 诊断的一种有价值且准确的工具。
