Table 1.
Information on three chemiluminescence immunoassay used for testing antibody of COVID-19.
Table 2.
Demographic laboratory characteristics of patients on admission.
Fig 1.
Distribution of the SARS-CoV-2 antibody S/CO index measured by three chemiluminescence immunoassays according to days after onset.
Fig 2.
Pearson’s correlation coefficient r and p-value between S/CO index of the three automated immunoassays.
Alinity CoV-2 IgG, Access CoV-2 IgG, and Atellica CoV-2 Total antibody presented strong correlations.
Fig 3.
Samples with SARS-CoV-2 antibody levels at different time points after the onset of symptoms from patients who showed confirmed/indeterminate results of COVID-19 molecular tests.
(A) Alinity CoV-2 IgG, (B) Access-CoV-2 IgG, and (C) Atellica CoV-2 Total antibody presented positive in all specimens after 21 days from symptom onset.
Fig 4.
Dynamic profiling of serum SARS-CoV-2 antibody measured by three chemiluminescence immunoassays.
The black arrow indicates the specimens showing inconsistency among the three equipment. (A) Alinity CoV-2 IgG on days 9, 12, and 16 was negative, and Access/Alinity showed positive on the same specimens. Only the specimens measured by Access on the 3rd day after symptom onset was negative (B) and positive (C). (D) Atellica CoV-2 Total antibody was positive on the 12th day, whereas the other two reagents were negative on the same specimen.
Table 3.
Patients showed discrepancy in SARS-CoV-2 antibody positivity in three automated immunoassay system.
Fig 5.
Pairwise association between clinical biomarkers indicating disease severity and SARS-CoV-2 antibody index.
Fig 6.
Mann-Whitney’s U comparison between (A) patients with severity and non-severe group (B) patients with and without underlying disease (C) patients classified by mortality. Access CoV-2 IgG antibody had a statistically significantly higher S/CO index in severe patients, patients with underlying disease, and patients who died. Alinity CoV-2 IgG antibody had a significantly more increased S/CO index in severe patients than in those of the non-severe group. *P < 0.05, **P < 0.005.