Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON M5S 1A8, Canada.
Department of Clinical Biochemistry, University Health Network, Toronto, ON M5G 2C4, Canada.
Viruses. 2021 May 22;13(6):962. doi: 10.3390/v13060962.
Dried blood spots (DBS) are commonly used for serologic testing for viruses and provide an alternative collection method when phlebotomy and/or conventional laboratory testing are not readily available. DBS collection could be used to facilitate widespread testing for SARS-CoV-2 antibodies to document past infection, vaccination, and potentially immunity. We investigated the characteristics of Roche's Anti-SARS-CoV-2 (S) assay, a quantitative commercial assay for antibodies against the spike glycoprotein. Antibody levels were reduced relative to plasma following elution from DBS. Quantitative results from DBS samples were highly correlated with values from plasma ( = 0.98), allowing for extrapolation using DBS results to accurately estimate plasma antibody levels. High concordance between plasma and fingerpick DBS was observed in PCR-confirmed COVID-19 patients tested 90 days or more after the diagnosis (45/46 matched; 1/46 mismatched plasma vs. DBS). The assessment of antibody responses to SARS-CoV-2 using DBS may be feasible using a quantitative anti-S assay, although false negatives may rarely occur in those with very low antibody levels.
干血斑（DBS）常用于病毒的血清学检测，在无法进行静脉采血和/或常规实验室检测时，是一种替代的采集方法。DBS 采集可用于广泛检测 SARS-CoV-2 抗体，以记录既往感染、疫苗接种情况，并可能评估免疫情况。我们研究了罗氏 Anti-SARS-CoV-2（S）检测试剂盒的特点，这是一种针对刺突糖蛋白的定量商业抗体检测试剂盒。DBS 洗脱后，抗体水平相对于血浆降低。DBS 样本的定量结果与血浆高度相关（=0.98），允许使用 DBS 结果进行外推，以准确估计血浆抗体水平。在 PCR 确诊的 COVID-19 患者中，在诊断后 90 天或更长时间检测时，观察到血浆和指尖 DBS 之间高度一致（45/46 匹配；1/46 血浆与 DBS 不匹配）。使用定量抗 SARS-CoV-2 检测试剂盒评估 DBS 中的抗体反应可能是可行的，尽管对于抗体水平非常低的患者，可能偶尔会出现假阴性。
