We evaluated the performance of a nucleoprotein-based enzyme-linked immunosorbent assay (ELISA) for detection of IgG antibodies to SARS-CoV-2.
The ELISA was based on serum IgG reactivity to a 46-kDa protein derived from the recombinant SARS-CoV2 nucleoprotein. Assay sensitivity was assessed using serum samples from 134 COVID-19 confirmed cases obtained > 15 days after symptom onset. Specificity was determined by testing sera from 94 healthy controls. Cross-reactivity was evaluated with sera from 96 individuals with previous dengue or zika virus-confirmed infections, with 44 sera from individuals with confirmed infections to other respiratory viruses or with bacterial and fungal infections that cause pneumonia and with 40 sera negative for SARS-CoV-2 nucleoprotein by commercial ELISA kits.
The majority of subjects were male and> 60 years old. Assay sensitivity was 90.3% (95% confidence interval 84.1% – 94.2%) and specificity was 97.9% (92.6% – 99.4%). There was no cross-reactivity with sera from individuals diagnosed with dengue, zika virus, influenza virus, rhinovirus, adenovirus, respiratory syncytial virus, seasonal coronavirus, Mycobacterium tuberculosis, Staphylococcus (S. aureus and coagulase-negative), Streptococcus pneumoniae, Klebsiella pneumoniae and the fungus Aspergillus fumigatus. The level of concordance of our test with results from commercial ELISA kits was 100%.
The nucleoprotein-based ELISA was specific for detection of IgG anti-nucleoprotein antibodies to SARS-CoV-2.. It utilizes a frequently employed low expense assay protocol and is easier to perform than other currently available commercial SARS-CoV2 antibody detection tests.
Copyright © 2021. Published by Elsevier B.V.
About The Expert
Tania Regina Tozetto-Mendoza
Kelly Aparecida Kanunfre
Lucy Santos Vilas-Boas
Evelyn Patricia Sanchez Espinoza
Heuder Gustavo Oliveira Paião
Mussya Cisotto Rocha
Anderson Vicente de Paula
Maura Salaroli de Oliveira
Daniella Bosco Zampelli
José Mauro Vieira
Lewis Buss
Silvia Figueiredo Costa
Ester Cerdeira Sabino
Steven S Witkin
Thelma Suely Okay
Maria Cassia Mendes-Correa
References
PubMed