Abstract
Objective: Real-time reverse transcription-polymerase chain reaction is the gold standard for the diagnosis of COVID-19, but it is necessary to utilize other tests to determine the burden of the disease and the spread of the outbreak such as IgG-, IgM-, and IgA-based antibody detection using enzyme-linked immunosorbent assay (ELISA).
Materials and methods: We developed an indirect ELISA assay to quantitatively measure the amount of COVID-19 IgG, IgM, and IgA antibodies present in patient serum, dried blood, and plasma.
Results: The population cutoff values for positivity were determined by receiver operating characteristic curves to be 1.23 U/mL, 23.09 U/mL, and 6.36 U/mL for IgG, IgM, and IgA, respectively. After albumin subtraction, the specificity remained >98% and the sensitivity was 95.72%, 83.47%, and 82.60%, respectively, for IgG, IgM, and IgA antibodies to the combined spike subunit 1 receptor binding domain and N proteins in serum. Plasma and dried blood spot specimens were also validated on this assay.
Conclusion: This assay may be used for determining the seroprevalence of SARS-CoV-2 in a population exposed to the virus or in vaccinated individuals.
Keywords: COVID-19; S1 RBD; SARS-CoV-2; dried blood; iELISA; nucleocapsid protein; serum/plasma.
【저자키워드】 COVID-19, SARS-CoV-2, nucleocapsid protein, S1 RBD, dried blood, iELISA, serum/plasma., 【초록키워드】 IgG, IgM, Seroprevalence, virus, ELISA, nucleocapsid protein, Receptor binding domain, Spread, polymerase chain reaction, serum, sensitivity, specificity, enzyme-linked immunosorbent assay, Antibody detection, outbreak, nucleocapsid, IgA, Patient, N protein, albumin, gold, plasma, characteristic, Blood, S1 RBD, ELISA assay, receiver operating characteristic, determined by, Chain Reaction, subunit, enzyme, gold standard, IgA antibodies, specimen, serum/plasma, real-time reverse transcription-polymerase chain reaction, material, vaccinated individuals, U/mL, cutoff value, N proteins, enzyme-linked immunosorbent, remained, the disease, determine, IgA antibody, diagnosis of COVID-19, 【제목키워드】 detection,