Divisions of Laboratory Genetics and Genomics and Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, United States of America.
Clinical Microbiology, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, United States of America.
PLoS One. 2021 May 28;16(5):e0252621. doi: 10.1371/journal.pone.0252621. eCollection 2021.
Dried blood spots (DBS) are an established specimen type for clinical testing given their low cost, ease of collection and storage, and convenient shipping capabilities through the postal system. These attributes are complementary to the expansion of SARS-CoV-2 serologic testing, which may be used to inform community seroprevalence rates.
The Luminex xMAP SARS-CoV-2 Multi-Antigen assay utilizes magnetic beads labeled with three viral antigens (nucleocapsid [NC], receptor binding domain [RBD], spike S1 subunit) to detect anti-viral IgG-class antibodies, and has Food and Drug Administration (FDA) Emergency Use Authorization (EUA) for use in serum and plasma. This assay was modified for use with DBS and validated against paired sera tested by one of two reference assays: the Roche Diagnostics Elecsys anti-SARS-CoV-2 ECLIA or the Euroimmun anti-SARS-CoV-2 IgG ELISA.
159 paired DBS and serum specimens analyzed using the modified Luminex xMAP assay on DBS and the reference methods on serum showed an overall concordance of 96.9% (154/159). Use of multivariate pattern recognition software (CLIR) for post-analytical interpretation of the Luminex xMAP DBS assay results, instead of manufacturer provided interpretive thresholds, increased overall qualitative result concordance to 99.4% (158/159) between the modified Luminex xMAP DBS and reference results.
Use of DBS for detection of antibodies against SARS-CoV-2 provides comparable results to those obtained using serum. DBS concordance was improved with multivariate pattern recognition software (CLIR). We demonstrate that DBS are a reliable specimen type for SARS-CoV-2 antibody detection using the modified Luminex xMAP assay.
鉴于其成本低、采集和存储方便以及通过邮政系统方便运输的特点，干血斑 (DBS) 已成为临床检测的既定标本类型。这些特性与 SARS-CoV-2 血清学检测的扩展相辅相成，后者可用于了解社区血清流行率。
Luminex xMAP SARS-CoV-2 多抗原检测法利用标记有三种病毒抗原（核衣壳 [NC]、受体结合域 [RBD]、刺突 S1 亚单位）的磁珠来检测抗病毒 IgG 类抗体，并且已获得食品和药物管理局 (FDA) 的紧急使用授权 (EUA) ，可用于血清和血浆。该检测法经过修改后可用于 DBS，并通过两种参考检测法之一（罗氏诊断 Elecsys 抗 SARS-CoV-2 ECLIA 或 Euroimmun 抗 SARS-CoV-2 IgG ELISA）对配对血清进行验证。
使用修改后的 Luminex xMAP 检测法对 DBS 和参考方法对血清进行分析的 159 对 DBS 和血清标本显示总体一致性为 96.9%（154/159）。使用多变量模式识别软件 (CLIR) 对 Luminex xMAP DBS 检测结果进行分析后解释，而不是使用制造商提供的解释阈值，将修改后的 Luminex xMAP DBS 和参考结果之间的定性结果总体一致性提高到 99.4%（158/159）。
使用 DBS 检测针对 SARS-CoV-2 的抗体可提供与使用血清获得的结果相当的结果。多变量模式识别软件 (CLIR) 提高了 DBS 的一致性。我们证明了使用修改后的 Luminex xMAP 检测法，DBS 是 SARS-CoV-2 抗体检测的可靠标本类型。
