Department of Medical Biochemistry, Lüleburgaz State Hospital, Kırklareli, Turkey.
Department of Medical Biochemistry, Harran University Faculty of Medicine, Şanlıurfa, Turkey.
Scand J Clin Lab Invest. 2021 Oct;81(6):469-474. doi: 10.1080/00365513.2021.1947522. Epub 2021 Jul 8.
D-dimer is considered to be a reliable marker of both coagulation activation and fibrinolysis. However, data on biological variation (BV) of D-dimer is still limited, causing the use of empiric analytical performance specifications and lack of other implications related to BV. This study aimed to estimate the BV of plasma D-dimer employing a study design compliant with The Biological Variation Data Critical Appraisal Checklist. Blood samples were collected from a cohort of 25 healthy subjects (16 females, 9 males; age range, 19-61 years) from Turkey once weekly for 3 consecutive weeks. All plasma samples were analyzed in duplicate within a single run on Roche Cobas c501. The results were assessed for outliers, variance homogeneity, normal distribution, and trend, followed by nested ANOVA to determine BV and analytical variation estimates with confidence intervals (CIs). Gender stratified BV estimates were also calculated. Within-subject (CV) and between-subject (CV) BV estimates with 95% CIs were for D-dimer 21.2% (17.8-25.9) and 30.9% (21.3-46.2), respectively. No significant BV differences were observed between females and males. The index of individuality (II) and the reference change value (RCV) were calculated as 0.71 and 60.4%, respectively. Analytical performance specifications for desirable imprecision, bias, and total error were 10.6, 9.4, and 26.8%, respectively. This study provides well-characterized BV estimates for D-dimer, which may be helpful for setting objectively analytical performance specifications. Moreover, RCV should be preferred to decide whether a significant difference is present between serial D-dimer measurements from an individual.
D-二聚体被认为是凝血激活和纤维蛋白溶解的可靠标志物。然而，关于 D-二聚体的生物学变异（BV）的数据仍然有限，导致使用经验性分析性能规格和缺乏与 BV 相关的其他含义。本研究旨在使用符合生物学变异数据关键评估清单的研究设计来估计血浆 D-二聚体的 BV。从土耳其的一个健康受试者队列（16 名女性，9 名男性；年龄范围 19-61 岁）中每周采集一次血样，连续采集 3 周。所有血浆样本均在罗氏 Cobas c501 上一次运行中进行双份分析。对离群值、方差同质性、正态分布和趋势进行评估，然后进行嵌套方差分析，以确定 BV 和分析变异估计值及置信区间（CI）。还计算了性别分层的 BV 估计值。D-二聚体的个体内（CV）和个体间（CV）BV 估计值的 95%CI 分别为 21.2%（17.8-25.9）和 30.9%（21.3-46.2）。女性和男性之间未观察到显著的 BV 差异。个体指数（II）和参考变化值（RCV）分别计算为 0.71 和 60.4%。理想不精密度、偏倚和总误差的分析性能规格分别为 10.6%、9.4%和 26.8%。本研究提供了 D-二聚体特征良好的 BV 估计值，这可能有助于设定客观的分析性能规格。此外，应该优先选择 RCV 来确定个体的连续 D-二聚体测量值之间是否存在显著差异。
