A Dried Blood Spot Protocol for high-throughput quantitative analysis of SARS-CoV-2 RBD Serology based on the Roche Elecsys System

Castelletti, Noemi; Paunovic, Ivana; Rubi-Acero, Raquel; Beyerl, Jessica; Plank, Michael; Reinkemeyer, Christina; Kroidl, Inge; Norena, Ivan; Winter, Simon; Olbrich, Laura; Janke, Christian; Hoelscher, Michael; Wieser, Andreas (2024): A Dried Blood Spot Protocol for high-throughput quantitative analysis of SARS-CoV-2 RBD Serology based on the Roche Elecsys System. A Dried Blood Spot protocol for high-throughput quantitative analysis of SARS-CoV-2 RBD serology based on the Roche Elecsys system. ISSN 2165-0497

Abstract

SARS-CoV-2 spreads pandemically since 2020; in 2021 effective vaccinations became available and 43 vaccination campaigns commenced. Still, it is hard to track the spread of the infection or to assess 44 vaccination success in the broader population. Measuring specific anti-SARS-CoV-2 antibodies is the 45 most effective tool to track the spread of the infection or successful vaccinations. The need for 46 venous-blood sampling however poses a significant barrier for large studies. Dried-blood-spots on 47 filter-cards (DBS) have been used for SARS-CoV-2 serology in our laboratory, but so far not to follow 48 quantitative SARS-CoV-2 anti-spike reactivity in a longitudinal cohort. We developed a semi-49 automated protocol or quantitative SARS-CoV-2 anti-spike serology from self-sampled DBS, 50 validating it in a cohort of matched DBS and venous-blood samples (n=825). We investigated 51 chromatographic effects, reproducibility, carry-over effects and calculated a positivity threshold as well 52 as a conversion formula to determine the quantitative binding units (BAU) in the DBS with confidence 53 intervals. Sensitivity and specificity reached 96·63% and 97·81%, respectively, compared to the same 54 test performed in paired venous samples. Between a signal of 0·018-250 U/mL we calculated a 55 correction formula. Measuring longitudinal samples during vaccinations, we demonstrated relative 56 changes in titres over time in several individuals and in a longitudinal cohort over four follow-ups. 57 DBS-sampling has proven itself for anti-nucleocapsid serosurveys in our laboratory. Similarly, anti-58 spike high-throughput DBS serology is feasible as a complementary assay. Quantitative 59 measurements are accurate enough to follow titre dynamics in populations also after vaccination 60 campaigns. This work was supported by the Bavarian State Ministry of Science and the Arts; LMU 61 University Hospital, LMU Munich; Helmholtz Centre Munich; University of Bonn; University of 62 Bielefeld; German Ministry for Education and Research (proj. nr.: 01KI20271 and others) and the 63 Medical Biodefense Research Program of the Bundeswehr Medical Service. Roche Diagnostics 64 provided kits and machines for analyses at discounted rates. The project is funded also by the 65 European-wide Consortium ORCHESTRA. The ORCHESTRA project has received funding from the 66 European Union’s Horizon 2020 research and innovation programme under grant agreement No 67 101016167. The views expressed in this publication are the sole responsibility of the author and the 68 Commission is not responsible for any use that may be made of the information it contains.

• Dokumententyp: Artikel (Klinikum der LMU)
• Organisationseinheit (Fakultäten): 07 Medizin > Klinikum der LMU München > Medizinische Klinik und Poliklinik IV (Endokrinologie, Nephrologie, weitere Sektionen)
• DFG-Fachsystematik der Wissenschaftsbereiche: Lebenswissenschaften
• DFG: Gefördert durch die Deutsche Forschungsgemeinschaft (DFG) - 491502892