Department of Laboratory Medicine, Busan, South Korea.
Biomedical Research Institute, Pusan National University Hospital, Busan, South Korea.
Am J Clin Pathol. 2022 Aug 4;158(2):206-211. doi: 10.1093/ajcp/aqac024.
Various preanalytical factors, including the collection tube, storage conditions, and centrifugation, affect the detection results of plasma cell-free DNA (cfDNA). We compared the effect of different centrifugation protocols on the detection of EGFR mutations in cfDNA.
We analyzed 117 plasma specimens from 110 patients with non-small cell lung cancer using the cobas EGFR Mutation Test v2 (Roche Diagnostics). We compared the identified EGFR mutations and semiquantitative index values from the 1- and 2-step centrifugation groups and confirmed the clinical impact of differences in the results after further high-speed centrifugation.
We detected EGFR mutations in 44 (37.6%) and 47 (40.2%) samples that were centrifuged once and twice, respectively; the 2 groups showed an 89.7% (105/117) concordance and a strong correlation in their semiquantitative index values (r = 0.929). Among the 12 inconsistent result pairs, 9 samples of 2-step centrifugation (75%) were consistent with the results of a recent tissue biopsy.
Additional high-speed centrifugation has been shown to increase the sensitivity of EGFR mutation detection in a commercial in vitro diagnostic real-time polymerase chain reaction device and is an optimal preanalytical factor for detecting low-allele frequency gene mutations using low concentrations of cfDNA.
多种分析前因素，包括采集管、储存条件和离心，都会影响血浆游离循环 DNA（cfDNA）的检测结果。我们比较了不同离心方案对 cfDNA 中 EGFR 突变检测的影响。
我们使用 cobas EGFR Mutation Test v2（罗氏诊断）分析了 110 例非小细胞肺癌患者的 117 份血浆样本。我们比较了 1 步和 2 步离心组鉴定的 EGFR 突变和半定量指数值，并在进一步高速离心后确认了结果差异的临床影响。
我们在分别经 1 次和 2 次离心的样本中检测到 EGFR 突变，分别为 44（37.6%）和 47（40.2%）；2 组的一致性为 89.7%（105/117），半定量指数值相关性很强（r=0.929）。在 12 对不一致的结果中，2 步离心的 9 个样本（75%）与最近的组织活检结果一致。
进一步高速离心可提高商业体外诊断实时聚合酶链反应设备中 EGFR 突变检测的灵敏度，是检测低浓度 cfDNA 中低等位基因频率基因突变的最佳分析前因素。
