a Central Laboratory , Vestfold Hospital Trust , Tønsberg , Norway.
Scand J Clin Lab Invest. 2019 Jul;79(4):247-250. doi: 10.1080/00365513.2019.1590858. Epub 2019 Apr 7.
Metylmalonic acid (MMA) and homocysteine (HCY) are important biomarkers in the assessment of cobalamin and folate metabolism. Correct interpretation of patient results benefit from knowledge of biological variation. The aim of the present study was to determine within-subject (CV) and between-subject (CV) biological variations of serum MMA and HCY in healthy women. We collected blood samples from 12 healthy volunteers (33-61 years) on the same weekday for 10 consecutive weeks. Samples were stored at -80 °C until analysis in duplicate in a single analytical run in random order. The CV and CV biological variations were estimated by CV-ANOVA after the data were first subjected to outlier and homogeneity analysis. The CV (95% CI) for MMA and HCY were 7.2% (6.1-8.5) and 7.4% (6.5-8.5), respectively. The corresponding CV were 21.1% (14.0-32.2) and 24.2% (16.2-36.8). The index of individuality (II) was 0.34 for MMA and 0.31 for HCY and the reference change value (RCV) was -17.7; 21.0 (% decrease; increase) for MMA and -16.2; 19.4 for HCY. We provide within- and between-subject biological variation estimates for MMA and HCY in healthy women using an updated protocol. The results will contribute to a better clinical interpretation of these biomarkers and be of aid when setting analytical performance specifications.
甲基丙二酸（MMA）和同型半胱氨酸（HCY）是评估钴胺素和叶酸代谢的重要生物标志物。正确解释患者的结果受益于对生物学变异的了解。本研究的目的是确定健康女性血清 MMA 和 HCY 的个体内（CV）和个体间（CV）生物学变异。我们在连续 10 周的每个工作日从 12 名健康志愿者（33-61 岁）收集血液样本。将样本储存在-80°C，直到以随机顺序在单个分析运行中重复分析。在对数据进行离群值和同质性分析后，通过 CV-ANOVA 估计 CV 和 CV 生物学变异。MMA 和 HCY 的 CV（95%CI）分别为 7.2%（6.1-8.5）和 7.4%（6.5-8.5）。相应的 CV 分别为 21.1%（14.0-32.2）和 24.2%（16.2-36.8）。个体指数（II）为 MMA 0.34 和 HCY 0.31，参考变化值（RCV）为-17.7；21.0（%降低；增加）为 MMA 和-16.2；19.4 为 HCY。我们使用更新的方案为健康女性提供了 MMA 和 HCY 的个体内和个体间生物学变异估计。这些结果将有助于更好地解释这些生物标志物，并有助于制定分析性能规范。
