tetano
Editor, Senior Moderator
Ann Clin Biochem
. 2020 Dec 3;4563220981106.
doi: 10.1177/0004563220981106. Online ahead of print.
EXPRESS: Development of a High Throughput SARS-CoV-2 Antibody Testing Pathway Using Dried Blood Spot Specimens
Stuart James Moat[SUP] 1 2 [/SUP], Wiola M Zelek[SUP] 3 [/SUP], Emily Carne[SUP] 4 [/SUP], Mark J Ponsford[SUP] 5 6 [/SUP], Kathyryn Bramhall[SUP] 7 [/SUP], Sara Jones[SUP] 8 [/SUP], Tariq El-Shanawany[SUP] 9 [/SUP], Matthew J Wise[SUP] 10 [/SUP], Annette Thomas[SUP] 11 [/SUP], Chloe George[SUP] 12 [/SUP], Christopher Fegan[SUP] 13 [/SUP], Rachael Steven[SUP] 14 [/SUP], Russell Webb[SUP] 14 [/SUP], Ian Weeks[SUP] 15 [/SUP], Brian Paul Morgan[SUP] 16 [/SUP], Stephen Jolles[SUP] 17 [/SUP]
Affiliations
Abstract
Background: Serologic assays for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) have roles in seroepidemiology, convalescent plasma-testing, antibody durability and vaccine studies. Currently, SARS-CoV-2 serology is performed using serum/plasma collected by venepuncture. Dried bloodspot (DBS) testing offers significant advantages; as it is minimally invasive, avoids venepuncture with specimens being mailed to the laboratory.
Methods: A pathway utilising a newborn screening laboratory infrastructure was developed using an Enzyme-Linked Immunosorbent assay (ELISA) to detect IgG antibodies against the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein in DBS specimens. Paired plasma and DBS specimens from SARS-CoV-2 antibody positive and negative subjects and PCR positive subjects were tested. DBS specimen stability, effect of blood volume and punch location were also evaluated.
Results: DBS from antibody-negative (n=85) and positive (n=35) subjects and PCR positive subjects (n=11) had a mean (SD; range) optical density (OD) of 0.14 (0.046; 0.03-0.27), 0.98 (0.41; 0.31-1.64) and 1.12 (0.37; 0.49-1.54), respectively. An action value OD >0.28 correctly assigned all cases. The weighted Deming regression for comparison of the DBS and the plasma assay yielded: y=0.004041+1.005x, r=0.991, Sy/x 0.171, n=82. Extraction efficiency of antibodies from DBS was >99%. DBS were stable for at least 28 days at ambient room temperature and humidity.
Conclusions: SARS-CoV-2 IgG RBD antibodies can be reliably detected in DBS. DBS serological testing offers lower costs than either point of care or serum/plasma assays that require patient travel, phlebotomy and hospital/clinic resources; the development of a DBS assay may be particularly important for resource poor settings.
Keywords: Clinical studies; Epidemiology studies; Immunoassay.
. 2020 Dec 3;4563220981106.
doi: 10.1177/0004563220981106. Online ahead of print.
EXPRESS: Development of a High Throughput SARS-CoV-2 Antibody Testing Pathway Using Dried Blood Spot Specimens
Stuart James Moat[SUP] 1 2 [/SUP], Wiola M Zelek[SUP] 3 [/SUP], Emily Carne[SUP] 4 [/SUP], Mark J Ponsford[SUP] 5 6 [/SUP], Kathyryn Bramhall[SUP] 7 [/SUP], Sara Jones[SUP] 8 [/SUP], Tariq El-Shanawany[SUP] 9 [/SUP], Matthew J Wise[SUP] 10 [/SUP], Annette Thomas[SUP] 11 [/SUP], Chloe George[SUP] 12 [/SUP], Christopher Fegan[SUP] 13 [/SUP], Rachael Steven[SUP] 14 [/SUP], Russell Webb[SUP] 14 [/SUP], Ian Weeks[SUP] 15 [/SUP], Brian Paul Morgan[SUP] 16 [/SUP], Stephen Jolles[SUP] 17 [/SUP]
Affiliations
- PMID: 33269949
- DOI: 10.1177/0004563220981106
Abstract
Background: Serologic assays for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) have roles in seroepidemiology, convalescent plasma-testing, antibody durability and vaccine studies. Currently, SARS-CoV-2 serology is performed using serum/plasma collected by venepuncture. Dried bloodspot (DBS) testing offers significant advantages; as it is minimally invasive, avoids venepuncture with specimens being mailed to the laboratory.
Methods: A pathway utilising a newborn screening laboratory infrastructure was developed using an Enzyme-Linked Immunosorbent assay (ELISA) to detect IgG antibodies against the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein in DBS specimens. Paired plasma and DBS specimens from SARS-CoV-2 antibody positive and negative subjects and PCR positive subjects were tested. DBS specimen stability, effect of blood volume and punch location were also evaluated.
Results: DBS from antibody-negative (n=85) and positive (n=35) subjects and PCR positive subjects (n=11) had a mean (SD; range) optical density (OD) of 0.14 (0.046; 0.03-0.27), 0.98 (0.41; 0.31-1.64) and 1.12 (0.37; 0.49-1.54), respectively. An action value OD >0.28 correctly assigned all cases. The weighted Deming regression for comparison of the DBS and the plasma assay yielded: y=0.004041+1.005x, r=0.991, Sy/x 0.171, n=82. Extraction efficiency of antibodies from DBS was >99%. DBS were stable for at least 28 days at ambient room temperature and humidity.
Conclusions: SARS-CoV-2 IgG RBD antibodies can be reliably detected in DBS. DBS serological testing offers lower costs than either point of care or serum/plasma assays that require patient travel, phlebotomy and hospital/clinic resources; the development of a DBS assay may be particularly important for resource poor settings.
Keywords: Clinical studies; Epidemiology studies; Immunoassay.