The accurate and prompt diagnosis of SARS-CoV-2 infection is required for the control and treatment of the coronavirus infection disease 2019 (COVID-19). In this study, we aimed to investigate the time courses of the anti-severe acute corona respiratory syndrome coronavirus 2 (SARS-CoV-2) IgM and IgG titers and to evaluate the sensitivity and specificity of such tests according to the specific day after the onset of COVID-19 among a patient population in Japan. We measured the titers of SARS-CoV-2 IgM and IgG in sera from 105 subjects, including 26 symptomatic COVID-19 patients, using chemiluminescent immunoassay (CLIA) methods utilizing magnetic beads coated with SARS-CoV-2 nucleocapsid protein and spike protein. The results of a ROC analysis suggested the possibility that the cutoff values in Japan might be lower than the manufacturer’s reported cutoff (10 AU/mL): 1 AU/mL for IgM and 5 AU/mL for IgG. The sensitivity of the test before Day 8 after symptom onset was less than 50%; at Days 9–10, however, we obtained a much higher sensitivity of 81.8% for both IgM and IgG. At 15 days or later after symptom onset, the SARS-CoV-2 IgG test had a sensitivity of 100%. These results suggest that if the number of days since disease onset is taken into consideration, these antibody tests could be very useful for the diagnosis of COVID-19 and similar diseases.
【저자키워드】 Infectious diseases, Diagnostic markers, 【초록키워드】 COVID-19, Treatment, CLIA, SARS-CoV-2, IgG, IgM, Coronavirus infection, coronavirus, Diseases, SARS-COV-2 infection, Infection, Spike protein, Protein, sensitivity, Sensitivity and specificity, antibody tests, symptomatic, sera, Japan, Antibody test, chemiluminescent immunoassay, respiratory, COVID-19 patients, SARS-CoV-2 IgM, ROC analysis, Magnetic beads, disease onset, titers, IgM and IgG, IgG test, symptom onset, Cutoff, respiratory syndrome coronavirus, cutoff value, SARS-CoV-2 nucleocapsid, IgG titers, magnetic bead, coronavirus infection disease, patient population, Course, evaluate, reported, Day, required, less, subjects, suggested, much higher, coated with, diagnosis of COVID-19, diagnosis of SARS-CoV-2, the SARS-CoV-2, 【제목키워드】 COVID-19, IgG antibody, Sensitivity and specificity, symptomatic, anti-SARS-CoV-2 IgM, time, Course,