Objectives We evaluated the performance of a nucleoprotein-based enzyme-linked immunosorbent assay (ELISA) for detection of IgG antibodies to SARS-CoV-2. Methods 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. Results 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 %. Conclusion 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.
【저자키워드】 COVID-19, SARS-CoV-2, ELISA, IgG antibody, Nucleoprotein antigen, 【초록키워드】 IgG, coronavirus, SARS-CoV2, protocol, Pneumonia, antibody, Infection, Influenza virus, virus, Adenovirus, cross-reactivity, Protein, sensitivity, specificity, infections, Antibody detection, Concordance, rhinovirus, respiratory syncytial virus, sera, male, Mycobacterium tuberculosis, Aspergillus fumigatus, Bacterial, Streptococcus pneumoniae, Staphylococcus, Fungal infection, Klebsiella pneumoniae, confirmed case, symptom onset, confidence interval, subject, individual, healthy controls, serum IgG, ELISA kit, SARS-CoV-2 nucleoprotein, serum sample, ELISA kits, objective, enzyme-linked immunosorbent, anti-nucleoprotein, Result, diagnosed, evaluated, was determined, majority, reactivity, other respiratory virus, 【제목키워드】 IgG,