Acibadem University, School of Medicine, Department of Medical Biochemistry, Istanbul, Turkey.
Marmara University, Arts and Science Faculty, Department of Statistics, Istanbul, Turkey.
Biochem Med (Zagreb). 2014 Feb 15;24(1):138-45. doi: 10.11613/BM.2014.015. eCollection 2014.
The ultra-large von Willebrand factor (vWF) multimers are very active and must be degraded by ADAMTS13 for optimal activity. A severe functional deficiency of ADAMTS13 has been associated with thrombotic thrombocytopenic purpura. The correct interpretation of patient vWF and ADAMTS13 plasma levels requires an understanding of the biological variation associated with these analytes. In the present paper, we aimed to determine the biological variation of ADAMTS13 and vWF in human adults.
Blood samples were collected weekly from 19 healthy subjects for 5 consecutive weeks. vWF activity and antigenicity were determined using aggregometric and immunoturbidimetric methods. ADAMTS13 antigenicity and activity were determined by ELISA.
The within-subject biological variations for vWF activity and antigenicity were 8.06% and 14.37%, respectively, while the between-subject biological variations were 18.5% and 22.59%, respectively. The index of individuality for vWF activity was 0.44, while vWF antigenicity was 0.64. Similarly, ADAMTS13 activity and antigenicity within-subject biological variations were 12.73% and 9.75%, respectively, while between-subject biological variations were 9.63% and 6.28%, respectively. The ADAMTS13 indexes of individuality were 1.32 and 1.55, respectively.
We report high biological variation and individuality in vWF antigenicity and activity levels. However, ADAMTS13 antigenicity and activity displayed high biological variation, but low individuality. Thus, population-based reference intervals may be useful for monitoring ADAMTS13 antigenicity and activity, but not for vWF, which displays high individuality. These findings should be considered when determining the reference interval and other clinical variables associated with ADAMTS13 and vWF levels.
超大的血管性血友病因子（vWF）多聚体非常活跃，必须通过 ADAMTS13 进行降解才能发挥最佳活性。ADAMTS13 的严重功能缺陷与血栓性血小板减少性紫癜有关。正确解读患者的 vWF 和 ADAMTS13 血浆水平需要了解与这些分析物相关的生物学变异。在本文中，我们旨在确定人类成年人中 ADAMTS13 和 vWF 的生物学变异。
从 19 名健康受试者中每周采集一次血液样本，连续采集 5 周。使用聚集和免疫比浊法测定 vWF 活性和抗原性。通过 ELISA 测定 ADAMTS13 抗原性和活性。
vWF 活性和抗原性的个体内生物学变异分别为 8.06%和 14.37%，而个体间生物学变异分别为 18.5%和 22.59%。vWF 活性的个体指数为 0.44，而 vWF 抗原性为 0.64。同样，ADAMTS13 活性和抗原性的个体内生物学变异分别为 12.73%和 9.75%，而个体间生物学变异分别为 9.63%和 6.28%。ADAMTS13 的个体指数分别为 1.32 和 1.55。
我们报告了 vWF 抗原性和活性水平的高生物学变异和个体差异。然而，ADAMTS13 抗原性和活性显示出高生物学变异，但个体差异较低。因此，基于人群的参考区间可能对监测 ADAMTS13 抗原性和活性有用，但对 vWF 则不然，因为 vWF 显示出较高的个体差异。在确定与 ADAMTS13 和 vWF 水平相关的参考区间和其他临床变量时，应考虑这些发现。
