A Multiplex Microsphere IgG Assay for SARS-CoV-2 Using ACE2-Mediated Inhibition as a Surrogate for Neutralization [Immunoassays]
The coronavirus disease 2019 (COVID-19) pandemic has highlighted the challenges inherent to the serological detection of a novel pathogen such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Serological tests can be used diagnostically and for surveillance, but their usefulness depends on their throughput, sensitivity, and specificity. Here, we describe a multiplex fluorescent microsphere-based assay, 3Flex, that can detect antibodies to three major SARS-CoV-2 antigens—spike (S) protein, the spike ACE2 receptor-binding domain (RBD), and nucleocapsid (NP). Specificity was assessed using 213 prepandemic samples. Sensitivity was measured and compared to that of the Abbott Architect SARS-CoV-2 IgG assay using serum samples from 125 unique patients equally binned (n = 25) into 5 time intervals (≤5, 6 to 10, 11 to 15, 16 to 20, and ≥21 days from symptom onset). With samples obtained at ≤5 days from symptom onset, the 3Flex assay was more sensitive (48.0% versus 32.0%), but the two assays performed comparably using serum obtained ≥21 days from symptom onset. A larger collection (n = 534) of discarded sera was profiled from patients (n = 140) whose COVID-19 course was characterized through chart review. This revealed the relative rise, peak (S, 23.8; RBD, 23.6; NP, 16.7 [in days from symptom onset]), and decline of the antibody response. Considerable interperson variation was observed with a subset of extensively sampled intensive care unit (ICU) pa...
Source: Journal of Clinical Microbiology - Category: Microbiology Authors: Cameron, A., Porterfield, C. A., Byron, L. D., Wang, J., Pearson, Z., Bohrhunter, J. L., Cardillo, A. B., Ryan-Muntz, L., Sorensen, R. A., Caserta, M. T., Angeloni, S., Hardy, D. J., Zand, M. S., Pecora, N. D. Tags: Immunoassays Source Type: research
More News: Coronavirus | COVID-19 | Intensive Care | Microbiology | Pandemics | Respiratory Medicine | SARS | Study