Department of Infection Control, Amphia Hospital, Breda, the Netherlands; Microvida Laboratory for Microbiology, Elisabeth-TweeSteden Hospital, Tilburg, the Netherlands; Microvida Laboratory for Microbiology, Amphia Hospital, Breda, the Netherlands.
Microvida Laboratory for Microbiology, Bravis Hospital, Roosendaal, the Netherlands.
J Clin Virol. 2020 Dec;133:104686. doi: 10.1016/j.jcv.2020.104686. Epub 2020 Nov 8.
Studies describing the performance characteristics of the cobas®6800 system for SARS-CoV-2 detection in deep respiratory specimens and freeze-thaw stability are limited. The current study compares the clinical performance of the automated SARS-CoV-2 assay on the cobas®6800 system to a lab-developed assay (LDA) and the cobas impact of freeze-thawing combined with lysis buffer.
Both retrospective and prospectively selected deep respiratory samples and oro- and nasopharyngeal samples in either E-swab® or GLY- were tested using the SARS-CoV-2 assay on the cobas®6800 System and compared to a lab developed assay. Additonally, SARS-CoV-2 RNA stability was assessed after one freeze-thaw cycle with or without lysis buffer.
In total, 221 (58.3 %) oro- and nasopharyngeal swabs, 131 (34.6 %) deep respiratory specimens, and n = 25 (6.6 %) swabs of unknown origin were included to study clinical performance. Only 4 samples gave discrepant results, all being positive in the LDA and not the cobas®6800 system. For stability testing, 66 samples without and 110 with lysis buffer were included. No clinically significant difference was found in test results after one freeze-thaw cycle and addition of lysis buffer.
Based on our findings, the cobas®6800 SARS-CoV-2 RNA assay yielded similar results as the LDA in oro-/nasopharyngeal swabs and deep respiratory specimens. Moreover, the cobas®6800 SARS-CoV-2 RNA assay yielded similar results before and after a freeze-thaw cycle, with better preservation of low viral loads in lysis buffer.
描述 cobas®6800 系统用于检测深部呼吸道标本和冻融稳定性的 SARS-CoV-2 性能特征的研究有限。本研究比较了 cobas®6800 系统上自动 SARS-CoV-2 检测与实验室开发检测（LDA）和 cobas 的临床性能 冻融结合裂解缓冲液。
使用 cobas®6800 系统上的 SARS-CoV-2 检测对回顾性和前瞻性选择的深部呼吸道标本以及 E-拭子或 GLY-中的口咽和鼻咽标本进行检测，并与实验室开发的检测进行比较。此外，评估了一个冻融循环后添加或不添加裂解缓冲液对 SARS-CoV-2 RNA 稳定性的影响。
总共纳入了 221 份（58.3%）口咽和鼻咽拭子、131 份（34.6%）深部呼吸道标本和 n=25 份（6.6%）来源不明的拭子，用于研究临床性能。仅 4 个样本出现不一致的结果，所有 LDA 阳性而 cobas®6800 系统阴性。对于稳定性测试，纳入了 66 个无裂解缓冲液和 110 个有裂解缓冲液的样本。在一个冻融循环和添加裂解缓冲液后，检测结果没有发现有临床意义的差异。
根据我们的发现，cobas®6800 SARS-CoV-2 RNA 检测在口咽/鼻咽拭子和深部呼吸道标本中与 LDA 产生相似的结果。此外，cobas®6800 SARS-CoV-2 RNA 检测在冻融循环前后产生相似的结果，在裂解缓冲液中更好地保存低病毒载量。
