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

Sibai, Mamdouh; Solis, Daniel; Röltgen, Katharina; Stevens, Bryan A.; Mfuh, Kenji O.; Sahoo, Malaya K.; Shi, Run Z.; Zehnder, James; Boyd, Scott D.; Pinsky, Benjamin A.

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.