National Center for Clinical Laboratories, Beijing Hospital, National Center of Gerontology and Graduate School of Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, P.R. China.
Department of Hematopathology, CBLPath/Sonic Healthcare, Rye Brook, NY, USA.
Clin Chem Lab Med. 2019 Apr 24;57(5):697-706. doi: 10.1515/cclm-2018-0915.
Background Flow cytometric enumeration of lymphocyte subsets in peripheral blood can provide important information about immune status. Commutable reference materials (RM) are crucial for maintaining accurate and comparable measurement results over time and space. Commutability assessment of RMs for lymphocyte subsets enumeration has not been reported elsewhere. Methods Lymphocyte subsets were measured in triplicate on 56 patient samples and eight RMs using two measuring systems commonly used in laboratories (FACS Canto II and Cytomics FC500). The first step was to determine the suitability of RMs and comparability of different systems with patient samples. After the requirements of suitability and comparability were met, the second step was to assess commutability following regression approach and difference in bias approach. Results Two RMs were not measurable on FC500 system for CD3-CD16/56+ and CD3-CD19+ percentages. The results of comparability showed no significant difference in the two systems. Eight RMs for CD3+CD4+ cell count, six RMs for CD3+ and CD3+CD8+ percentages, five RMs for CD3-CD16/56+ percentage, and three RMs for CD3-CD19+ percentage were commutable using the two approaches. For CD3+, CD3+CD8+ and CD3-CD19+ percentages, the results of regression approach showed that one RM was non-commutable for each parameter, while the other approach showed that the RM was commutable. Conclusions The suitability of RM and comparability of different measuring systems are prerequisites for assessing commutability. This study indicated that different approaches led to different results. The difference in bias approach is recommended for criteria relating to medical requirements and performance characteristics of measuring systems in use.
背景 外周血淋巴细胞亚群的流式细胞术计数可提供有关免疫状态的重要信息。可互换的参考物质（RM）对于在时间和空间上保持准确和可比的测量结果至关重要。对于淋巴细胞亚群计数的 RM 的可互换性评估尚未在其他地方报道过。
方法 使用两种实验室常用的测量系统（FACS Canto II 和 Cytomics FC500），在 56 个患者样本和 8 个 RM 上重复测量了淋巴细胞亚群 3 次。第一步是确定 RM 的适用性和不同系统与患者样本的可比性。在满足适用性和可比性的要求后，第二步是使用回归方法和偏差差异方法评估可互换性。
结果 在 FC500 系统上，有 2 个 RM 无法测量 CD3-CD16/56+和 CD3-CD19+的百分比。两个系统的可比性结果无显著差异。使用两种方法，有 8 个 RM 可用于 CD3+CD4+细胞计数，6 个 RM 可用于 CD3+和 CD3+CD8+的百分比，5 个 RM 可用于 CD3-CD16/56+的百分比，3 个 RM 可用于 CD3-CD19+的百分比。对于 CD3+、CD3+CD8+和 CD3-CD19+的百分比，回归方法的结果表明，每个参数都有一个 RM 不可互换，而另一种方法则表明 RM 是可互换的。
结论 RM 的适用性和不同测量系统的可比性是评估可互换性的前提条件。本研究表明，不同的方法导致了不同的结果。建议使用偏差差异方法来确定与测量系统的医疗要求和性能特征有关的标准。
