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 ... -  《-》

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》

Detection of SARS-CoV-2 IgG antibodies in dried blood spots.

The COVID-19 pandemic led to development of numerous serologic tests. To obviate the need for phlebotomy services, we validated dried blood spots (DBS) for anti-SARS-CoV-2 serologic testing. Immunoglobulins were extracted from 3 mm DBS punches and the extracts were analyzed using the Euroimmun anti-SARS-CoV-2 IgG ELISA. Various pre-analytical factors were studied. Results were favorable for DBS stored for at least 67 days at or below 37°C. Comparison between paired serum and DBS specimens tested by the Euroimmun ELISA showed 96.8% and 81.3% positive and negative agreement, respectively, indicating that confirmatory testing of positive Euroimmun results on DBS extracts is necessary to achieve clinical accuracy. Our findings suggest that any SARS-CoV-2 antibody assay that requires pre-dilution of serum is amenable to DBS as an alternate specimen type that is relatively low cost, self-collectable, stable, can be shipped by standard mail and could be used to establish the seroprevalence of large populations.

Turgeon CT ，Sanders KA ，Granger D ，Nett SL ，Hilgart H ，Matern D ，Theel ES ... -  《-》

Validation of a multiplex flow immunoassay for detection of IgG antibodies against SARS-CoV-2 in dried blood spots.

Turgeon CT ，Sanders KA ，Rinaldo P ，Granger D ，Hilgart H ，Matern D ，Theel ES ... -  《PLoS One》

High seroprevalence for SARS-CoV-2 among household members of essential workers detected using a dried blood spot assay.

McDade TW ，McNally EM ，Zelikovich AS ，D'Aquila R ，Mustanski B ，Miller A ，Vaught LA ，Reiser NL ，Bogdanovic E ，Fallon KS ，Demonbreun AR ... -  《PLoS One》