Evaluation of SARS-CoV-2 Total Antibody Detection via a Lateral Flow Nanoparticle Fluorescence Immunoassay

Background The coronavirus disease 2019 (COVID-19) endgame may benefit from simple, accurate antibody testing to characterize seroprevalence and immunization coverage Objectives To evaluate the performance of the lateral flow QIAreach anti-SARS-CoV-2 Total rapid nanoparticle fluorescence immunoassay compared to reference isotype-specific IgG, IgM, and IgA SARS-CoV-2 ELISA using S1 or receptor binding domain (RBD) as antigens Study design A diagnostic comparison study was carried out using 154 well-characterized heparin plasma samples Agreement between assays was assessed by overall, positive, and negative percent agreement and Cohen’s kappa coefficient Results Overall agreement between the QIAreach anti-SARS-CoV-2 Total and any anti-spike domain (S1 or RBD) antibody isotype was 96 0% (95% CI 89 8 to 98 8), the positive percent agreement was 97 6% (95% CI 91 0 to 99 9), the negative percent agreement was 88 2% (95% CI 64 4 to 98 0) The kappa coefficient was 0 86 (95% CI 0 72 to 0 99) Conclusion The QIAreach anti-SARS-CoV-2 Total rapid antibody test provides comparable performance to high-complexity, laboratory-based ELISA