National Center for Clinical Laboratories, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing Hospital/National Center of Gerontology, Beijing, P.R. China.
Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, P.R. China.
Clin Chem Lab Med. 2022 Jun 9;60(9):1393-1402. doi: 10.1515/cclm-2021-1283. Print 2022 Aug 26.
Accurate measurement of serum folate is essential for the diagnosis and management of various disorders. This study aims to investigate the between-method differences of four immunoassays and a rapid isotope-dilution liquid chromatography-tandem mass spectrometry (ID-LC-MS/MS) method.
Roche Cobas (USA), Abbott Alinity i2000 (USA), Beckman Coulter Access (USA), Mindray CL-6000i (China), and the ID-LC-MS/MS method were compared using 46 human serum samples. The results were analysed by Passing-Bablok regressions and Bland-Altman plots. A bias of 13.31% based on biological variation was used as the bias criterion.
All the within-run and total coefficients of variation (CVs) met the specification. The folate concentrations determined by all the assays were significantly different (p=0.0028). All assays had correlation coefficients over 0.97 with each other. The 95% confidence intervals (CIs) for the slope seldom contained 1 and few 95% CIs for the intercept contained 0 in the regression equations. Compared to ID-LC-MS/MS, the biases of all assays ranged from -20.91 to 13.56 nmol/L, and the mean relative biases ranged from -9.85 to 40.33%. The predicted mean relative biases at the medical decision levels rarely met the criterion.
Assays for serum folate had good correlations with each other but lacked good agreement. The accuracy and consistency of assays for serum folate should be measured and assessed routinely. Standardization work to improve the accuracy of serum folate assays, such as the extension of traceability to reference methods or materials, calibration standardization efforts, and assay-adjusted cut-offs should be promoted.
准确测量血清叶酸对于各种疾病的诊断和治疗至关重要。本研究旨在探讨四种免疫分析法与快速同位素稀释液相色谱-串联质谱法（ID-LC-MS/MS）之间的方法差异。
使用 46 份人血清样本比较罗氏 Cobas（美国）、雅培 Alinity i2000（美国）、贝克曼库尔特 Access（美国）、迈瑞 CL-6000i（中国）和 ID-LC-MS/MS 方法。采用 Passing-Bablok 回归和 Bland-Altman 图分析结果。以基于生物学变异的 13.31%偏倚作为偏倚标准。
所有批内和总变异系数（CV）均符合要求。所有检测方法测定的叶酸浓度均有显著差异（p=0.0028）。所有检测方法之间的相关系数均大于 0.97。回归方程中斜率的 95%置信区间（CI）很少包含 1，截距的 95%CI 很少包含 0。与 ID-LC-MS/MS 相比，所有检测方法的偏倚范围为-20.91 至 13.56 nmol/L，平均相对偏倚范围为-9.85 至 40.33%。在医学决策水平上预测的平均相对偏倚很少符合标准。
血清叶酸检测方法之间具有良好的相关性，但缺乏良好的一致性。应常规测量和评估血清叶酸检测方法的准确性和一致性。应推动标准化工作，以提高血清叶酸检测方法的准确性，如将溯源性扩展至参考方法或物质、校准标准化工作以及检测调整的截止值。
