Clinical validation of novel dried blood spot based collecting device using serum separation for measuring SARS-CoV-2 antibodies.

Accurate surveillance of coronavirus disease 2019 (COVID-19) incidence includes large-scale antibody testing of the population. Current testing methods require collection of venous blood samples by a healthcare worker, or dried blood spot (DBS) collection using finger prick, however this might have some logistic and processing limitations. We investigated the performance of the Ser-Col device for detecting severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) antibodies using a finger prick: DBS-like collection system that includes a lateral flow paper for serum separation and allows for automated large scale analysis. For this prospective study, adult patients with moderate to severe COVID-19 were included 6 weeks post-symptom onset. Healthy, adult volunteers were included as a negative control group. Venous blood and capillary blood using the Ser-Col device were collected and the Wantai SARS-CoV-2 total antibody ELISA was performed on all samples. We included 50 subjects in the study population and 49 in the control group. Results obtained with venous blood versus Ser-Col capillary blood showed 100% sensitivity (95% CI: 0.93-1.00) and 100% specificity (95% CI: 0.93-1.00). Our study shows the feasibility of SARS-CoV-2 total antibody screening using a standardized DBS technique with semiautomated processing for large scale analysis.

Schuurmans Stekhoven SJ ，Winkel KGT ，Souverein D ，Sondermeijer BM ，van Houten MA ，Euser SM ，van Lelyveld SFL ... -  《-》

Comparison of Dried Blood Spots and Venous Blood for the Detection of SARS-CoV-2 Antibodies in a Population of Nursing Home Residents.

Meyers E ，Heytens S ，Formukong A ，Vercruysse H ，De Sutter A ，Geens T ，Hofkens K ，Janssens H ，Nys E ，Padalko E ，Deschepper E ，Cools P ... -  《Microbiology Spectrum》

Evaluation of dried blood spots as alternative sampling material for serological detection of anti-SARS-CoV-2 antibodies using established ELISAs.

During the current pandemic, antibody testing based on venous serum helps to determine whether the tested person has been previously infected with SARS-CoV-2. Alternatively, capillary blood can be taken via a finger prick (dried blood spots, DBS). In this study, paired DBS and venipuncture samples were tested using two serological assays to evaluate the usability of DBS for the detection of anti-SARS-CoV-2 antibodies. Paired samples of DBS and venous serum were collected from 389 volunteers, of whom 75 had a recent PCR-confirmed SARS-CoV-2 infection, and tested for anti-SARS-CoV-2 IgG antibodies against both viral S1 and nucleocapsid protein (NCP) antigens using two ELISAs. Degree of agreement and correlation coefficients between ELISA results based on the two sampling methods were calculated. Results of DBS showed almost perfect agreement and high correlations with results from corresponding serum samples in both the S1-based ELISA and the NCP-based ELISA. ELISA results derived from DBS showed very high agreement to those obtained with serum, supposing adequate usability and robustness of DBS as sample material for detection of anti-SARS-CoV-2 antibodies. In the near future, large-scale epidemiological screening for antibodies against SARS-CoV-2 will be carried out. Since DBS reduce the strain on healthcare institutions regarding sample collection, they have a potential to facilitate efficient community- and population-based screening in the current SARS-CoV-2 pandemic.

Weisser H ，Steinhagen K ，Höcker R ，Borchardt-Lohölter V ，Anvari Ö ，Kern PM ... -  《-》

Validation of dried blood spot sampling for detecting SARS-CoV-2 antibodies and total immunoglobulins in a large cohort of asymptomatic young adults.

Detecting antibody responses following infection with SARS-CoV-2 is necessary for sero-epidemiological studies and assessing the role of specific antibodies in disease, but serum or plasma sampling is not always viable due to logistical challenges. Dried blood spot sampling (DBS) is a cheaper, simpler alternative and samples can be self-collected and returned by post, reducing risk for SARS-CoV-2 exposure from direct patient contact. The value of large-scale DBS sampling for the assessment of serological responses to SARS-CoV-2 has not been assessed in depth and provides a model for examining the logistics of using this approach to other infectious diseases. The ability to measure specific antigens is attractive for remote outbreak situations where testing may be limited or for patients who require sampling after remote consultation. We compared the performance of SARS-CoV-2 anti-spike and anti-nucleocapsid antibody detection from DBS samples with matched serum collected by venepuncture in a large population of asymptomatic young adults (N = 1070) living and working in congregate settings (military recruits, N = 625); university students, N = 445). We also compared the effect of self-sampling (ssDBS) with investigator-collected samples (labDBS) on assay performance, and the quantitative measurement of total IgA, IgG and IgM between DBS eluates and serum. Baseline seropositivity for anti-spike IgGAM antibody was significantly higher among university students than military recruits. Strong correlations were observed between matched DBS and serum samples in both university students and recruits for the anti-spike IgGAM assay. Minimal differences were found in results by ssDBS and labDBS and serum by Bland Altman and Cohen kappa analyses. LabDBS achieved 82.0% sensitivity and 98.2% specificity and ssDBS samples 86.1% sensitivity and 96.7% specificity for detecting anti-spike IgGAM antibodies relative to serum samples. For anti-SARS-CoV-2 nucleocapsid IgG there was qualitatively 100% agreement between serum and DBS samples and weak correlation in ratio measurements. Strong correlations were observed between serum and DBS-derived total IgG, IgA, and IgM. This is the largest validation of DBS against paired serum for SARS-CoV-2 specific antibody measurement and we have shown that DBS retains performance from prior smaller studies. There were no significant differences regarding DBS collection methods, suggesting that self-collected samples are a viable sampling collection method. These data offer confidence that DBS can be employed more widely as an alternative to classical serology.

Ferentinos P ，Snape D ，Koivula F ，Faustini S ，Nicholson-Little A ，Stacey M ，Gifford R ，Parsons I ，Lamb L ，Greeves J ，O'Hara J ，Cunningham AF ，Woods D ，Richter A ，O'Shea MK ... -  《-》

Performance of Immunoglobulin G Serology on Finger Prick Capillary Dried Blood Spot Samples to Detect a SARS-CoV-2 Antibody Response.

Nikiforuk AM ，McMillan B ，Bartlett SR ，Márquez AC ，Pidduck T ，Kustra J ，Goldfarb DM ，Barakauskas V ，Sinclair G ，Patrick DM ，Sadarangani M ，Ogilvie GS ，Krajden M ，Morshed M ，Sekirov I ，Jassem AN ... -  《Microbiology Spectrum》